Sailboat Hull & Deck Repair

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/

THE INTERNATIONAL MARINE SAILBOAT LIBRARY

SAILBOAT HULL & DECK !T

^r

REPAIR

H^

DON CASEY

i.

THE INTERNATIONAL MARINE SAILBOAT LIBRARY

SAILBOAT

HULL & DECK REPAIR DON CASEY

S=-

m

^

INTERNATIONAL MARINE CAMDEN, MAINE

Public Llbrarj'

^ \.

c^.

Saiisaulo. California

949

)5

M.

CONTENTS

Introduction

4

Leaks

6

Choosing a Sealant

8

Rebedding Deck Hardware Preparing a Cored Deck for

30

Understanding Polyester Resin

66

Sanding

34

Grinding

69

Scratch Repair

36

The

15

— ATennporary 17

Rebedding Deadlights

18

Replacing Portlights

21

Mast Boots

24

Hull-to-Deck Joint

24

Centerboard Trunks

27

Through-Hull Fittings

27

Pressurizing to Find Leaks

29

Deck Repairs

40

Stress Cracks

42

Voids

45

Crazing (Alligatoring)

47

Renewing Nonskid

51

Teak Decks

55

Is

Essential

Basics of Fiberglass Lay-up

When 14

Solution

64

32

New

Sealing Chainplates

Laminate Repair

Buffing

10

Hardware

Sealing Portholes

Restoring the Gloss

to Use

Epoxy

70

74

M.

^)

f mr^

f0k

^. ' /

-4^

/

/

mS^ %r\^ Core Problems

78

Hull Repairs

92

Delamination

80

Gouges

94

Wet Core

82

Blisters

98

Damaged Core

85

Impact

Reinstalling the Skin

87

and Rudder Damage

Keel

Weeping

Strengthening

89

Stiffening a Skin

90

Damage

104

116

Keel

Keel/Centerboard Pivot Problems Hull

Damage Around

119 Fins

and Skegs

Damaged Rudder Blade/Shaft

Movement

External Ballast

Index

114

120 121

123

124

126

Copyright Information 134

—

INTRODUCTION: BEAUTY

MORE THAN

IS

Likewise molded glass-reinforced plastic boats.

Fiberglass.

Legendary yacht designer L Francis Herresiioff has

— somewhat inelegantly,

it

seems to

me

but

how many of Herreshoff's

boats have ended up as lobster condominiums or fuel for a

the

boat shed stove, while snot-built boats of

same

how

age, no matter

undeserving of

and estuaries? Wooden boats

regularly die

early deaths of natural causes; fiberglass boats

particular

I

wooden boats, and in Herreshoff's wooden boats. There is

love

decades.

much

to is

love

I

material of

If

you want

a boat to display,

recommend

it,

many boatowners to conclude that

often low,

difficult.

elicits

Any

we hope to quell

pages that

The craftsmanship of the builder

is

obvious:

pound

curves, knees cut

harness the tree's joints

wedding

evident

a natural

crook to

a thick layer of fiber

and

craft

a

is

far less

boat-shaped

sticky glop.

the dried glop pops out of the mold with the graceful curves yields

But

it

isn't

perspective. in

no redemption.

redemption that If

That

same

we open

is

called for;

china.

yachts,

Why

not

the leaded glass doors

we are likely to encounter fine wooden plates, woven bowls?

Because china dishes forced clay

—

a can of gelcoat paste or a bit of glass cloth resin

and give

it

a whirl. You'll

is

buy

to

and

wonder what you

were worried about. this

book

is

confined to

repairs to fiberglass boats,

it is

hull

glass repairs. Fiberglass boats are not

Decks, for example, balsa, or

foam,

may be cored

railed

and deck

not limited to fiberall

fiberglass.

with plywood,

with aluminum, covered with

teak, outfitted with bronze, interrupted with acrylic, it's

the galley of one of Mr. Herreshoff's classic

wooden

way you can

purge yourself of any nagging doubts

While

strength, precise dovetail

and beam. Such

formed by painting

in a hull

mold with

full

shelf

from

com-

fol-

the skeptics with astound-

fully

planks steamed to linguini and worried into

repair

assertion to the contrary too

raised eyebrows. In the

and manipulating boat.

fiber-

A lesser-known virtue of fiberglass is that it is repair. A fiberglass hull's seamless nature

ingly clear explanations, but the only

into the flowing contours of a

has

easy to

something magical about taking straight lumber it

wood

but for a boat to use,

hard to beat.

must be

me wrong;

malleable, durable, and easy to

choice for boat construction for more than three

leads

must be assassinated. Don't get

is

made fiberglass the overwhelming

glass

immortality, continue to ply the world's oceans, bays,

Fiberglass

maintain. These characteristics, widely known, have

Maybe beautiful wooden

called this versatile material "frozen snot." so,

SKIN DEEP

molded bone-rein-

— are infinitely more serviceable.

penetrated with stainless rubber. Virtually

all

steel,

of these

regular maintenance and

and booted with

components

require

occasional repair,

and

they must be assembled properly and carefully the boat

is

if

to be dry.

Watertight joints are our

first

order of business.

Boatowners today don't need even a passing

acquaintance with irons;

molded

oakum

hulls are

completely seamless, and

the fiberglass hull that leaks, no matter

rare

is

old.

Deck

The

dirty

boats with molded-in nonskid

how

leaks are, unfortunately, another matter. little

secret of fiberglass boats

is

that

most

more watertight than a colander. Wash-down water? A significant amount of all three finds its way below. are only slightly

drip

leaks don't just

on bunks, and

wood

wet the contents of

trickle across soles;

lockers,

they destroy

and delaminate

core, corrode chainplates,

bulkheads. Identifying and eliminating leaks

Those with planked decks in

essential. This

book

details the

most

effective tech-

It

instructs

you

in

Eventually, of course, a hull-and-deck-repair

book for fiberglass boats must come around

also

how to

locate pesky leaks.

Often

all

that

is

test

your work and

a fiberglass hull

is

gloss can be the easiest of repairs to fiberglass;

where we begin our exposition of this affect

a

An older fiberglass deck hairline cracks,

may have

is

likely

to be

webbed

it is

hulls.

with

even pocked with open voids, and

stress cracks radiating

5

shows you how to

hull repairs

from corners or

quick look

in

Chapter 7

in

Chapter

4.

of the materials

deck to perfection are

provided.

after

at

on

blis-

impact damage. A

common

repairmg will

rud-

have taken the

cannon.

When

boats were built of wood, a truly pro-

all

fessional repair required the

skills

of

someone with

years of experience. Not so with fiberglass. Pay

deck that

is

a

it

virtually

a try,

no

and you

will

discover

repair to a fiberglass hull or

motivated owner can't do as well

as quickly) as a pro.

by the necessity of

deck delamination and

der and keel problems, and you

that there

repairs are complicated

will find

— dealing with gouges, repairing

ways to

repair these blemishes. Step-by-step

repair

and reconstructing

attention and give

Deck

is

replace spongy core. Chapter 6 focuses

from beneath hardware. Fortunately there are easy

instructions for restoring the

You

answers to these questions and more

ters,

material.

decks more than

should you use

when epoxy? What

vinylester? Cloth, mat, or roving?

how to

wrong with

When

ready to take on more complicated repairs. Chapter

chalky surface or a few scratches. Restoring the

The ravages of time

providing clear and concise descriptions of the

involved and guided by clear illustrations, you are

portlight replace-

shows you how to

It

to

repairs requiring fiberglass lay-up, but not without first

Armed with an understanding

ment, hull-to-deck joints, and centerboard trunk repairs.

be more interested

overlay.

provides specific sealant recommendations for

various uses.

the included

the section detailing the care and repair of teak

polyester resin and

nique for sealing joints and bedding hardware, and it

will

various materials to be used.

is

will find

of

instructions for renewing those surfaces useful.

Spray? Rain?

Deck

Owners

providing effective nonskid surfaces.

caulking and firming

Frozen snot, indeed!

(if

not

ly

Q \ V -Vx^CVv.

!*ni

o

LEAKS

Leaks are insidious. A tiny leak, left unattended for months or years, can easily result in

dannage that

or take innumerable hours

will

if

cost thousands of dollars to have repaired,

you make the

repairs yourself.

There are the obvious things: ruined interior varnish below leaking ports,

mildewed upholstery from

trickles

from the hull-to-deck joint,

punky cabin

a

sole from "mysterious" rainwater intrusion.

As serious as these to the deck core,

age

is

are, they're small potatoes.

The biggest

and you may not see any evidence of a

from leaks

risk

leak until major

dam-

already done.

The decks of most fiberglass boats are made up of a plywood or sandwiched between two skins of fiberglass. saturation but

no

duction boats.) result

is

is

likely

If

less

(Closed-cell foam,

susceptible to delamination,

is

found

balsa core

more

resistant to

in relatively

few pro-

water penetrates the fiberglass skin and gets into the core, the

to be failure of the

bond between the core and the

core delamination weakens the deck. Delamination

is

skin(s).

accelerated

if

This

the boat

is

subjected to temperatures that cause the trapped water to freeze and expand.

The water entering like filling a jug.

a

cored deck cannot get back out; the flow

Balsa cores

become

saturated and mushy. Plywood soon

is

deck.

rots. In

cutting

prevented with four-bits' worth of caulk and an hour's worth of

become

one way,

away the fiberglass skin and replacing After you do this job once, knowing full well that it could have been

both cases, the only solution the core.

is

religious

about maintaining

a watertight seal

effort,

you

around any hole

in

will

the

—

CHOOSING A SEALANT You walk into a marine store and there they are, dozens of different cartridges and tubes standing on Geez,

how many

Three. That's

shelves, stacked in bins,

different kinds of it.

and hanging

in blister cards.

marine sealants can there be?

Three. Understand these three and you have the selection

process whipped.

POLYSULFIDE Polysulfide sealants;

is

Army

the Swiss

you can use

called Thiokol (a

for

it

best choice for bedding teak

marine

knife in

almost everything. Often

trademark for the polymer that

types of sealant, often taking a

is

reach

the main ingredient of all polysulfide sealants regardless of manufacturer), polysulfide

As a bedding

compound

ments associated with

stress

allows for

it

be sanded

after

it

Use polysulfide Polysulfide

bonds

compound

cures and

it

POLYURETHANE

since

causing

can

to harden

and

any

some

split.

attack both. or Delrin tings

Any

or PVC,

plastic fitting

— such as quality

— may be

safely

and polysulfide

made of epoxy,

plastic through-hull

bedded with

doesn't turn loose. Poly-

such a tenacious adhesive that

is

should be thought of as permanent;

you

will

want

if

will

nylon, fit-

its

there

to separate the

is

bond any

two

don't use polyurethane to seal them.

Use polyurethane anywhere you want a permathe best sealant for the hull-to-

nent joint. This

is

deck joint.

also a

fittings

It is

and

good choice

fortoerails

and

for through-hull

rubrails,

but not

some teak cleaners

on most

plastics

—

acrylic,

if

they

soften

Like polysulfide, polyurethane should not

to bed plastic deck fittings

ABS

urethane

it

are raw teak because

or polycarbonate

(including portlight frames); plastic marine fittings

are generally either

the bulldog of marine sealants

gets a grip,

parts later,

use polysulfide to bed plastic port-

it

it

is

likelihood that

takes paint well.

as well to plastic surfaces as to

lights, either acrylic (Plexiglas)

(Lexan). Don't use

is

for everything except plastic.

them

Specifically, don't

it

once

by

seal

other, but the solvents in the sealant attack plastics,

week or more to

cure.

Polyurethane

gripping tenaciously to both surfaces. Polysulfide also an excellent caulking

full

move-

and temperature

change, yet maintains the integrity of the

trim.

a syn-

is

thetic rubber with excellent adhesive characteristics.

and

rails

Polysulfides are the slowest curing of the three

it.

be used

polycarbonate, PVC, or

ABS.

The cure time

for

polyurethane

shorter than polysulfide, but

still

is

generally

may be up to a

week.

polysulfide.

The black caulking between the planks of a teak deck

is

polysulfide. For this application, a

two-part polysulfide gives the best

Because polysulfide adheres well to teak cial

8

(a

spe-

primer improves adhesion), and because

unaffected by harsh teak cleaners,

>- LEAKS

SILICONE

results.

it is

it is

also the

seem like the snake oil of the marine sealant trio. A bead of this modern miracle is too often expected to cure any and every leak. And it Silicone can

A POLYSULFIDE USE: All purpose deck hardware, through-hull sealant for

wood

trim, etc.

Caulking

SILICONE

bedding

USE: Gaskets. Portlight bedding.

fittings,

compound

Insulation for

Good flexibility and allows removal of bedded parts. May

teak decks. for easier

attack plastics

1

— not recommended for $

1

3

per

1

0-ounce

joint,

then tighten after

cure.

cartridge.

CLEANUP: Trim and

METHOD OF APPLICATION: Snug joint,

"roll" off

excess after cure.

then tighten after cure.

CLEANUP: Trim and

me-

0-ounce cartridge.

Snug $9 to

dissimilar

METHOD OF APPLICATION:

portlights.

COST RANGE:

between

Not for use below waterline. COST RANGE: $6 to $ 1 per

tals.

CURE TIME:

peel off excess

SHELF

1

to 7 days.

LIFE: 10 to 20 years.

after cure.

CURE TIME: SHELF

2 to 7 days.

LIFE: 2 to 5 years.

POLYURETHANE USE: A permanent sealant for through-hull fittings and hull-to-

deck joints. May attack plastics— not

recommended

COST RANGE: ounce

for portlights,

S7 to $1 5 per 10-

cartridge.

METHOD OF APPLICATION: Bead between parts to be assembled.

CLEANUP:

Mineral

before

spirits

cure.

CURE TIME: SHELF

does

2 to 7 days.

LIFE: 5 to 10 years.

— for about as long as

magic

elixir

salesman to

bead releases tube

full

worm.

its

grip,

wrist action,

not

lost

up

is

at least catch dinner.

a gasket material — period.

number

you

will find

it is

abilities as

If

tempo-

the best product for a

of sealing requirements.

It is

between components that must be

periodically dismantled

— beneath hatch

slides, for

example.

as a

as a dangling rubber

you think of silicone's adhesive rary at best,

ket material

— with a hook and the right

you can

Silicone sealant

used to take the

out of town. Then the

and what started out

of promise ends

All is

it

slip

the only one

Silicone retains

resilience for

its

decades and

is

unaffected by most chemicals, but

it

should not be

used below the waterline. Because

it

depends upon

mechanical compression to maintain

cone

is

its

seal,

sili-

not the best choice for sealing hardware on

a cored deck.

Exposed

but repels paint

like

silicone

is

a

magnet

for dirt

an opposite pole, so never fillet

of the marine sealant trio than can be safely used to

with silicone, and don't use this sealant on any sur-

bed

face you plan to paint.

plastic.

It is

similar metals

an excellent insulator between

— use

it

when mounting

hardware to an aluminum

spar.

It is

dis-

stainless

the perfect gas-

Silicone sealants typically set in a

and usually reach

full

cure

in less

few minutes

than 24 hours.

CHOOSING A SEALANT

A USEFUL HYBRID THERE IS A BIG ADVANTAGE TO USING A SEALANT with good adhesive properties. An adhesive sealant maintains

its

seal

even when stresses

pull or pry

the

ness of silicone. Although silicone has amazing elasticity, its

lack of adhesion

bedded components apart, the sealant stretching and compressing lii- LEAKS

is

guaranteed to return greater

relative

Remove the fitting. This

is

usually the hardest part of

the job, either because access to the fasteners ficult to

gain or because the bolts are frozen

is

dif-

— or

both. Access sometimes requires removing headlin-

by simply

ers or cabinetry, but don't try to avoid this

running a bead of sealant around the

do

you

that, eventually

ting, only this

time

In

will

fitting.

If

you

be removing the

still

fit-

preparation for major deck

repair.

For access to the fasteners securing

wooden

components, the bungs hiding the bolt heads

will

have to be removed. This can be accomplished by drilling a small

hole

in

the center of the bung and

threading a screw into

when

it;

the point of the

screw finds the screw head below the bung, continuing to turn the screwdriver Extracting

the bung hole. with a

will

lift

the bung.

way can sometimes damage A safer method is to drill the bung

bungs

bit slightly

this

smaller than the diameter of the

bung, then carefully remove the remaining ring of material with a small chisel. If

the

fitting

was

installed with polyurethane,

removing the fasteners may have to pry the fitting loose

the deck and the cially

metal

is

fitting.

fittings) or

likely

little

to result

Heating the

effect. in

Trying

damage

to

fitting (espe-

the deck can coax the

polyurethane to release

its

grip.

HEADUNERS HEADLINERS ARE AS VARIED AS BOATS. If the headliner is fiberglass, you likely cannot remove it (without removing the deck). Occasionally manufacturers bolt

hardware to the deck before

the headliner. You liner

will

installing

have to cut or

drill

it

over

the head-

beneath the fasteners to gain access.

liner

and

pulling the liner loose at that end.

staples out with a flat screwdriver at the

Work the

seams

until

you

uncover the desired area. Be sure you use Monel staples

when you

replace the

liner.

For

Canvaswork and Sail Repair in

more on

headliners, see

this series.

Reinstall

the hardware with longer bolts through spacers and

deck

a backing plate that covers the cutout.

When

the headliner

is

made up of panels,

it is

usually captured by trim pieces screwed in place.

may also attach with Velcro. Sewn headliners are typically stapled to wooden strips across the overhead. You can't see the staples Panels

because they are through the excess material onthe back side at the seams. You gain access by removing the trim piece at the forward or aft

end of the

spacers

backing

headliner

V o

plate

B!a-j)rjnt*^*^wt'7j«

REBEDDING DECK HARDWARE

>-

11

Clean off the old bedding. Every trace of the old sealant

must be removed. Use

or a wire brush as required,

and the

fitting

a blade, sandpaper,

and clean both the deck

with acetone.

Mask adjacent

areas. Cleaning

up the squeeze-

out with solvent takes twice as long as masking

and

is

trace

ten times

around

it

more messy.

Dry-fit

with a pencil. This

is

strengthen the mounting location

"Deck

Repairs").

pencil line

Mask the deck

the part and

the time to

if

required (see

Vs inch outside the

and mask the edge of the

fitting.

Coat both surfaces with sealant. Cut the

tube or cartridge

at a 45° angle

tip of

— close to the

the

tip for

a thin bead, farther back for a thicker bead. (Cart-

ridges have an inner seal

with an ice

pick.)

you

will

have to puncture

Apply the sealant with a forward

motion, pushing the bead

in

front of the nozzle.

Coat both surfaces to make sure there

any gaps

in

will

not be

the bond; use a putty knife to spread the

sealant evenly, like buttering bread. Before inserting

the mounting bolts

— not screws — run

sealant around each just

a ring of

below the head. NEVER

apply sealant around the fasteners on the underside of the deck;

if

the seal with the outer skin breaks,

you want the water to pass into the cabin where will

12

5^ LEAKS

be noticed.

it

—

"

Assemble the parts and "snug" the fasteners enough to squeeze sealant out

all

the

Wait

until

silicone,

way around.

then

the sealant partially cures

24 hours

fully

for polysulfide or

— 30 nninutes for

polyurethane

tighten the bolts by turning the nuts only

to prevent breaking the seal around the shank of

the bolt.

If

the

fitting

draw them one

is

attached with screws, with-

at a time, run a

bead of sealant

around the shank beneath the head, turn,

7-^^::::r-

y^~^ ^**!>*^

"^s-i^

x^

then drive them

^

f^

C^^

^'7

/\^_i^

in

Trim away the excess squeeze-out

by running the

fitting,

a razor blade

around

then peeling away the

around the edge; dirt,

a

fillet

silicone attracts

polyurethane yellows, and

polysulfide

^M

each

home evenly.

masking tape. Never leave

/^ih ^ ^/^ ?

8

all

reinstall

so you

weakens

want the

sealant visible

in

least

of

fitting. Install

new bungs, matching and

amount

— only the thin

edge beneath the grain

the sun,

setting

color

and

them with

varnish.

REBEDDING DECK HARDWARE

>

13

—

PREPARING A CORED DECK

FOR NEW HARDWARE marine good Asnever depend on them the core of a deck or hole

in

Anytime you

drill

or cut a

large

A

procedure before

do

fitting,

chucked

nail

power

into a

cut oversize.

Vacuum cavity;

you

Redrill

the cavity with

way

a

is

remove

as a

the cured epoxy.

two-

Sand and clean the

First seal

area that

duct tape, then pour

under the

Now you

catalyzed epoxy into

the cavity

When

is full,

ture the tape

to

let

the epoxy run out back into

your glue container. Filling the cavity with unthick-

ened epoxy allows the epoxy to better penetrate the edge of the core. Retape the bottom hole. there are several mounting holes, drain in turn until

all

fill

If

each and

have been treated and

all

resealed.

The second step is to thicken the epoxy (the same mix you have already poured through the holes) with colloidal

tency.

Now

fill

silica

each cavity

allow the epoxy to cure

>- LEAKS

will

be

fitting.

are ready

bed the new

hardware as

punc-

and

bottom holes

filler.

the mount-

the bottom hole with

the top hole.

14

whatever

ing holes through

epoxy. The most secure

from the

can't

will act

drill.

the pulver-

ized core

step process.

core

this easily with a

bent

doesn't need to be

Fill

to a

mayonnaise consis-

level

fully.

with the deck and

you are rebed-

time, be certain that

reinstalling the fitting.

the hole. You can

example

first

If

the core has been properly sealed, or follow this

within V2 inch of

hole— for a

through-hull

ding old hardware for the

Remove all the

fastener

holes oversize.

for

hull.

to keep water out of

the deck, seal the exposed core with epoxy

Drill all

1

before mounting any hardware.

sealants are, you should

as

detailed

in

the

previous section.

SEALING CHAINPLATES When water culprit

is

finds

way below, very often the

a leaking chainplate. Chainplates'

propensity to leak

understandable; they are bed-

is

ded under moderate sail

its

fixed stress, but

once under

usually not to the deck;

enough not to have chainplate openings located a cored section of the

yours).

It is

the

yanked and eased while the leeward chainplates

sealant lower

are virtually released. This tries the grip of any

before

They are also stressed

by poor sheet

leads,

in unfair

rig

deck (but you should check

that

is

at risk.

directions

shroud encounters with the

on the chainplate stops the leak

enters the cabin. This results

it

ure.

shroud or stay runs

down

the wire and across the

As annoying and potentially damaging as a leak

plates that

is,

the larger

is

often from chain-

appear to be watertight. The danger

Remove the trim

1

risk

plate ifthere

one.

is

lem

— short of catastrophic

is

Pull

bolts

chainplate.

necessary to

you

plate

shroud or stay by

check

if

corrosion.

doesn't

the

It Is

only

easily,

If it

come out

pass a long,

only one shroud at a

round screwdriver

time. Before releas-

shaft

ing a stay always set

pinhole and sup-

up

port the

end on

wooden

block

port the mast.

to pull the

for signs of

buckle and pulling

a halyard to sup-

is

you want to

It

slackening the turn-

Disconnect

—

prob-

remove the chain-

disconnect the

pin.

failure

this

below deck

way, but rebedding if

fail-

the mounting

taped up out of the

easier

chainplate

you rebed them.

and extract the

much

in

hidden by the deck

it. If you have never fully examined your chainplates, or if it has been a few years, you are strongly urged to pull them before

This can usually be

is

is

will,

chainplate and examine

turnbuckle directly to the chainplate.

into the cabin

Because the erosion

and/or sealant, the only way to detect

and spray gathered by the attached

the chain-

sion resistance of stainless steel, this situation

over time, almost certainly result

body support coming aboard. When the seal

in

plate sitting in a ring of water. Despite the corro-

dock, and by the use of shrouds for

rain

the seal at the

If

or as handholds for fails,

in

deck breaks, water penetrates, but additional

the windward chainplates are alternately

sealant.

most manufacturers know

while

through the

lifting

a

on the

handle.

SEALING CHAINPLATES

»

15

Dig

all

oftheoldcauikfromthehole. Apieceof

hacksaw blade can be

useful for this, but

be careful

not to enlarge the hole through the deck; the tighter the chainplate

fits,

the less

longer your bedding job trim plate,

it

move, and the

will

will last.

Clean the deck,

and chainplate of old bedding. Examine the caulk area carefully; any

the chainplate

in

ting, cracks, or

brown

ment. Wipe

pit-

discoloration indicate replace-

down the deck, trim

plate, chainplate,

and the inside of the hole with acetone.

Reinstall the chainplate

trim plate

and trace around

above the trim plate.

the

is little

install its fasteners.

to be gained by two-stage tight-

ening, so tighten these screws

squeeze out of the

16

>- LEAKS

slot

and

all

fully.

Sealant should

around the

line,

the chainplate

chainplate. Use the

flat

of a

and the bottom of the trim

plate

with sealant.

Because the trim plate screws are generally quite small, there

with a pencil. Mask

between the chainplate and the deck

Butter the deck

\\

and

the

flexible putty knife to force sealant into the crack.

\\

position

Dry-fit

and the top surface of the trim

way around the

>

- LEAKS

and the

through-hull threads and flange with polyurethane

all

and

tighten;

around the outside

away the excess and use some

the heads of the flange

bolts.

of

it

to

PRESSURIZING

TO FIND LEAKS

Some leaks into the cabin are obvious, but most aren't.

travel

Water may leak through the deck, then

along the top of a headliner

feet or

1

more

before finding an exit and dripping out. The traditional

way of finding

Shut

all

leaks

is

seacocks and close

moving the hose incrementally "up" the deck the drip appears. This method often

method

that requires a bit

more

fails.

effort,

until

Here

but

is

a

will

it

locate every leak.

to flood the deck,

all

hatches.

1

Use duct tape to to be airtight,

hawsepipes,

seal

i.e.,

all

openings you don't expect

ventilators, cockpit hatches,

etc. Seal

plastic sheeting (a

the

companionway with

garbage bag

will

be adequate)

edge-taped over the hatch and the dropboards.

Insert the nozzle of a small electric leaf

blower into

an open ventilator or deck plate and seal tape.

it

with

A shop-vac with the hose on the "blow"

side

will also serve.

With the blower running (give pressurize

all

water over

it

five nninutes to

the internal spaces), sponge soapy

ports, hatches, and hardware. Anywhere you see bubbles, you have a deck

After

all

you rebed the

identified fitting,

leak.

you can

pressure-test again to confirm that the leak

is

resolved, but don't leave the tape in place for

than a few hours

have great

— never overnight — or you

difficulty

removing

more

will

it.

FINDING LEAKS

>-

29

30

RESTORING THE GLOSS Production fiberglass

boats are built by laying

nnultiple laminates into a

The bright

interior of

the mold

and coated with

then the

first layer,

polished mirror-

to get a reasonably

is

agent (wax);

a releasing

is

sprayed onto

layer of fiberglass

initial

is

added

the builder achieves

until

due

This

is

opposite of the

are manufactured, tion

is

son

to spray

it's

way most other products

where the

on the

finish

last

produc-

in

— presumably the rea-

called the finish. Gelcoat

the

is

Gelcoat also differs from paint tant ways.

step

in

is

mechanical

start.

other impor-

— that Passion

Crimson enamel on your old Roadmaster ing

on

(or not)

hang-

by gripping microscopic scratches

put there by sanding or chemically etching the metal.

Between gelcoat and the underlying

nates, the

bond

is

chemical; the resin saturating the

layer of glass material

first

This

a single

— not unlike pouring warm gelatin over cold.

is

called chemical cross-linking,

because gelcoat

resin

and

and the polyester

it

occurs

resin

used

to saturate the layers of fiberglass material are the

same basic product. Gelcoat mented polyester resin.

is

essentially pig-

Good

is

paints are self-leveling

much

—

like

water

— drying

to a smooth, glossy finish, but gelcoat resin

new fiberglass

boats

is

thicker than a paint finish. For

finish (Awlgrip)

to 0.002 inch) thick. layer of a boat just mils, give or

to 2 mils (0.001

popped from the mold In

is

is

20

other words, the

typically thinner

page of this book, while

a single will

is 1 .5

The thickness of the gelcoat

take 3 or 4 mils.

than

a layer of gelcoat

normally be about 10 pages thick.

A well-applied

gelcoat

(like

everything

else,

there are quality differences between manufacturers) will

generally

last

care. Protected with

compounded its

10 years with minimal or no

an annual coat of wax and

in later years,

gelcoat can maintain

gloss for 20 years or more. is

due

primarily to

its

The longevity of gel-

thickness.

When

the sur-

face dulls and chalks, the "dead" layer can be

abraded

off

and the fresh surface underneath

pol-

ished to restore the gloss.

Thickness can also be the enemy.

If

the builder

— often done with the best intentions on early fiberglass boats — applies the gelcoat too thickly

it

eventually cracks

Gelcoat resin has poor flow characteristics.

but the "wet-

example, the dry film thickness (DFT) of a typical

coat

combines with the

exposed surface of the gelcoat to form

mass

lami-

finish,

entirely to the highly polished interior surface

Gelcoat

Fruit is

smooth

paint on a painted surface

The bond between paint and the under-

lying surface

taking on the texture of

can be thinned and sprayed

of the mold.

polyurethane

the desired thickness.

It

look" gloss characteristic of

applied to the "back" side of the gelcoat, and additional layers are

like plaster,

boat-shaped mold.

called gelcoat,

the mold surface. The

behaves more

the application tool.

like

dried

mud. A

faulty resin for-

mulation can also cause cracking and crazing. Except for color matching, gelcoat repairs are easy and straightforward.

31

BUFFING The most common surface malady of fiberglass boats

is

a dull finish. This

is

brought on almost entirely by exposure and can be delayed significantly by regularly

waxing the gelcoat.

perhaps even chalky, waxing

When will

unprotected gelcoat becomes

no longer restore the

gloss.

dull

and porous,

The damaged surface

must be removed by buffing the gelcoat with rubbing compound.

START WITH A CLEAN SURFACE

Wash. Scrub the surface thoroughly with

1

of

1

a solution

cup of detergent per gallon of water; choose

liquid detergent,

even more phate

such as Wisk. To make the solution

effective, fortify

(TSP), available at

surface

a

it

with trisodium phos-

any hardware

store.

shows any signs of mildew, add

a

If

the

cup of

Degrease. Soap solutions

surface,

sweep

in

MEK

suspension longer.) Protect

your hands with rubber gloves and turn the rag often,

available.

dry.

or

with an MEK-soaked rag. (Acetone

holds contaminants

oughly and

it

it

can also be used, but the slower-evaporating

chlorine bleach to the mix. Rinse the surface thorlet

may fail to remove oil

grease from the porous gelcoat. To degrease the

changing

it

when

a clean area

Dewax. Rubbing compound works

no longer

is

like

very fine

sandpaper, and wax on the surface can cause

uneven cone on

cutting. In addition, it

if

the surface has

(nine boats out often do), the

sili-

compound

drags the silicone into the bottom of microscopic scratches,

which

paint the hull.

will

cause you grief

Wipe the

hull

if

you ever

with rags soaked

toluene or a proprietary dewax solvent. Wipe single direction, usually diagonally

toward the waterline.

32

>-

RESTORING THE GLOSS

in

in a

downward

CHOOSE THE RIGHT COMPOUND Gelcoat

AUTDMDTIVE

much

is

compound. coat

is

in

softer than paint

Select a

and requires

compound formulated

a gentler

rubbing

for fiberglass.

If

the gel-

especially bad shape, the heavier abrasion of an automotive

compound can

provide faster surface removal, but

it

must be used

with caution to avoid cutting through.

FIBERGLASS „,,^n RUBBING CDMPDLiNU

•^

PLUG

IN

Rubbing compound can be buffed out by hand the area

is

small, but hand-buffing

an entire boat

not recommended. An orbital polisher

cheaper than an

artificial

a buffing disk into

your

through the gelcoat, or ning

it

if

is

is

far

elbow. Don't try chucking

electric you'll

eat right

drill; it will

burn up the

drill

run-

slow.

THE RIGHT PRESSURE How much

of the surface the

relates directly to

Since you always

how much

You

much

that

will

pressure you apply.

want to remove

as necessary, never use any required.

compound removes as

the process

is

how

it

hull

a small repair

with the aid of a machine,

the same. Working a small area at a

time, apply the

compound

to the surface by hand,

with a circular motion. Use heavier

initially,

then progressively reduce the

pressure until the surface If

is

is.

by hand or an entire

pressure

gelcoat

have to experiment with

Whether you are compounding

then buff

little

more pressure than

becomes

glassy.

the gelcoat shows swirl marks, buff them out

with a very fine finishing

compound.

BUFFING

>-

33

SANDING Sometimes the dead

layer of old gelcoat

compound becomes by sanding the surface through the gelcoat, restore

its

interminable.

first.

In

so deep that removing

is

with rubbing

that case, the process can be accelerated

This only works

if

the gelcoat

too thin to restore and you

it is

it

will

is

thick;

if

you sand

have to paint the surface to

gloss.

HIGH SPEED AND HIGH RISK Don't

let

the sander

run over any high spots, ridges, or

corners, or

It

will

cut

through the gelcoat regardless of

how thick it

is.

Change paper

when

the

amount of sanding dust

diminishes.

/^S^'-'^V

'•.-..

M> / The

1

220-grit

way to sand gelcoat is by hand, but you the time required to remove the dead sur-

safest

can slash

face layer by using a

power sander. You

V4-sheet finishing sander

Load

it

with

brown). spot to

It is

1

a

make

20-grit

good

— called

working

at

a

aluminum-oxide paper

sure your gelcoat

about 200

in

is

thick

^

maintain contact. This

much first

to

mind that the sander

orbits per second, so

seconds. Apply only as

keep a

is

Hi

it

few

pressure as needed to

pass removes most of

the material;

if

good

from the remaining steps are

>-

a

(it's

enough

moving and don't sand any area more than

results

need

will

palm sander.

idea to start in an inconspicuous

take this treatment. Keep

34

='i^^t

the gelcoat doesn't get transparent,

RESTORING THE GLOSS

likely.

When you have

run the sander over the entire area,

change to 220-grit paper and do

it

again.

WET SAND

Remove the

1

scratch marks

power sanding

left

behind by wet sanding the surface with 400-grit wet-or-dry (silicone carbide) sandpaper.

Hand sand

To ensure

a

uniform surface, backing sandpaper

with a rubber or idea,

but

—

when you

wooden

the

grit

is

block

is

usually a

very fine

same

good

— 320 or and perhaps

with a circular motion, keeping a trickle of water

higher

running on the sanding area.

better control from finger-backed sanding. Fold the

will

get the

results

sandpaper as shown to keep the paper from sanding

itself

and to provide three

fresh faces

from each

piece of paper.

J

Wear

cloth

garden gloves

— the

kind with the

hard dots

— to

save the tips of your fingers.

Make

X

\

I

a final pass with 600-grit wet-or-dry

paper

and the surface should be ready to buff to

a like-

new gloss.

WHAT? THE HIGH SPEEDS OF PALM SANDERS— about 14,000 rpm— can result damaging shriek. Earplugs are available from any drugstore for about

in

an ear-

buy and use them. Not only will they save your hearing, but by eliminating the fatigue that accompanies such an assault on the senses, they actually make this a buck;

a pair

job

much

easier.

SANDING

>

35

SCRATCH REPAIR Scratches

are less visible

ferent color base.

good

If

some

the surrounding gelcoat

condition, always

though the gelcoat application may

on gelcoat than on

paint since they don't cut through to

make

is

dif-

in

blend imperceptibly with the

damage

surface

try to repair a

You

too thin to

is

and

if

paste. Paste

the

you want

thickened to a

permanent

or screwdriver

chamfer on both

matching the

selection of pigments

down

can be purchased for

sides.

Even prohave diffi-

color.

is

one of the few

for conditioning yourself to

be

happy with a self-assessment of "not bad." You can purchase gelcoat as unpigmented resin, in a kit

with a half-dozen different colors of

inorganic pigments, or

most popular

in "factory"

colors won't

colors for the

boats. Because pigments fade,

boat has seen a few years

match

in

if

a

the sun, even factory

exactly.

For small repairs to a white boat, a

kit

with

pigments should serve; getting close is much easier with white, and once the repair is buffed out to a gloss, smalt shading differences will be unnoticeable.

36

containing

amount of gel-

less

RESTORING THE GLOSS

than $20.

For colored hulls

repairs daily

culty getting a perfect match. This

may call

what

ener along with a

a

it.

and

places that

is

coat paste and hard-

filling

THE HARDEST PART OF A REPAIR TO THE SURFACE is

thicker

for scratch

repair. Kits

a small

WHAT COLOR IS WHITE?

do gelcoat

in a

putty form called

the

fill

and

rather than

draw the corner of a scraper

fessionals that

gelcoat

bridges the scratch

To get

of a fiberglass boat

will find

resin

with

it

paste, the paste

a

damage the

painting over

resin

and put

For

available as both a

scratch,

it

hull.

scratch by simply

is

the scratch to open

the

GELCOAT CHOICES

gelcoat. Gelcoat resin

repair,

be

underlying laminates, see "Hull Repairs."

OPENING A SCRATCH FOR REPAIR Never

rest of

dealing with deeper gouges that also

Even

repairs with gelcoat rather than paint.

it

initially

can be sanded smooth and polished to

rough,

larger repairs,

getting an adequate

match cult.

It

is

more diffi-

essentially

requires tinting an

ounce of gelcoat with one drop of pigment at a time and touching the resulting mix to the hull until you get a match. Keep track of the number of drops of each tint per ounce to reach the right color. Guys, get your wives or girlfriends to help you with this part; men are eight times more likely to have defective color vision a minus that becomes a plus if your repair

—

is

slightly off (you

won't notice).

For additional assistance

see Sailboat Refinishing

in

matching

in this series.

colors,

CATALYZING The hardener for gelcoat

is

the

same

as for

any polyester

ketone peroxide, or MEKP. Gelcoat resin usually requires

resin 1

— methyl ethyl

to 2 percent of hard-

ener by volume (follow the manufacturer's instructions). As a general

drops of hardener

will

catalyze

1

ounce of

resin at

kick (start to harden) in less than 30 minutes.

probably

\dea\.

Always

err

the hardener thoroughly; repair will

on the side of too if

you

fail

1

percent.

Hardening

little

in

rule,

four

The mix shouldn't

about two hours

hardener. Also be certain to

is

stir in

to catalyze every bit of the resin, parts of the

be undercured.

SPREADING GELCOAT PASTE

Apply gelcoat paste

like

any other putty;

a plastic

spreader works best. Let the putty bulge a

behind the spreader; polyester as

it

cures,

and you're going to sand the patch any-

way. Just don't extra

Original gelcoat

1

is

bond between

is

strictly

it

bulge too

much

or you'll

make

bond

mechanical

applies

a long-cured hull

and an application of fresh gelcoat over scratch

let

for yourself.

chemically bonded to the under-

lying laminates, but this molecular

only to lay-up; the

work

little

resin shrinks slightly

—just

a ding or

like paint.

Wiping

the scratch with styrene just prior to coating can partially reactivate

some chemical ter this step

is

the old gelcoat and result

in

crosslinking, but as a practical mat-

usually omitted.

Scrape up any excess beyond the patch area.

SCRATCH REPAIR >

37

I

COVERING THE REPAIR

Gelcoat

will

not

fully

cure

in air.

remain smooth and the gelcoat

Large repairs require a

will

not adhere to

it.

coating of polyvinyl alcohol (PVA) to seal the surface

Tape one edge of the

(see "Laminate Repair"), but to seal a scratch repair,

the repair, then smooth the plastic onto the gelcoat and

cover

it

with a sheet of

plastic.

A

section of kitchen "zip-

per" bag works especially well because

it

tape

down

plastic to

the remaining sides.

tends to

SANDING AND POLISHING GELCOAT REPAIRS After

24 hours, peel away the

plastic.

The annount of sanding required

on how smoothly you applied the gelcoat.

For a scratch repair, a 5-inch length of

1

1

x 2

makes

convenient sanding block. Wrap the block with or

1

fine

50-grit paper,

1

and use the narrow side to con-

your sanding to the

new

strokes, taking care that the

gelcoat. Use short

paper

is

sanding only

the patch and not the surrounding surface. Never

do

this initial

sanding without a block backing the

paper.

38

RESTORING THE GLOSS

a

20-

will

depend

the surface just beyond

When

the

new gelcoat

is

flush,

put 220-grit wet-or-

dry paper on your block and wet sand the repair, feathering

it

into the old gelcoat until

you can

Switch to 400-grit wet-or-dry, abandoning the block,

and wet sand the surface appearance. Follow

until

it

has a uniform

with 600-grit wet-or dry.

this

detect no ridge with your fingertips.

Dry the area and use rubbing gelcoat a high gloss.

On

compound

small repairs,

to give the

you can buff

the gelcoat up to a gloss by hand. Give the repair area a fresh coat of wax.

If

sonably good, the repair

your color match

will

be

virtually

is

rea-

unde-

tectable.

SCRATCH REPAIR

>

39

40

DECK REPAIRS

A

fiberglass boat

molded

in

Most of the furniture and machinery before the deck goes on

If

you

good

life

stay off the rocks

—

two

like filling a

and don't smash

It is

is

born to a

life

assaulted by

of abuse.

It

rain, pollution,

sits

and the deck.

open

hull

box before putting on the

lid.

into the dock, the hull has a pretty

out

and

sections: the hull

installed inside the

is

— coddled by the water and always half

other hand, desert.

typically

is

in

foot.

in

the shade. The deck, on the

the sun It is

like a

piece of Nevada

eviscerated by openings,

pierced by hardware, pried by cleat and stanchion.

You might think that

to stand

up to such treatment, decks are

the hull they cover. You'd be wrong. Weight carried low

built as

—

as strongly

in a

boat has

lit-

make the hull as thick as he feels like but weight carried high reduces stability. A deck must first be light; strength is defined by "strong enough." As a result, the need for deck repairs is far more

tle

detrimental impact

common

^^

Deck

than the need for repairs to the

is

a

hull.

be more complicated (but not necessarily "harder").

repairs can also

While the surface of a

deck

a builder can

hull

is

flat

or uniformly curved

and

landscape of corners, angles, curvatures, and textures.

extends under deck-mounted hardware. Backside access

molded

relatively featureless, a

headliner.

And

Damage

may be

often

inhibited by a

to provide stiffness without weight, deck construction

generally involves a core. In this

chapter

constraint;

we will

confine repairs to surface damage. This

most deck problems are

is

hardly a

limited to the deck's top surface.

41

—

STRESS CRACKS RECOGNIZING STRESS CRACKS Stress cracks are easy to identify

by

their shape. Typically the cracks run

You will see parallel cracks in molded corners, such as around the perimeter of the cockpit sole or where the deck intersects the cabin sides. These suggest weakness in the corner. Parallel cracks also show up on either side of bulkheads or other stiffening components attached to the inside surface of the hull or deck. The concentration of flexing stresses at such "hard spots" causes the gelcoat, and sometimes the underlying laminate, to crack. parallel or fan

Starburst cracks are also caused by flexing, but

case the

movement

falling against lifelines or

in this

by pulling oneself aboard with

the top of the stanchion, which

up around the socket mounting

3^

in starburst pattern.

centers at a point rather than along

an edge. The most common starburst cracking extends from beneath stanchion mounts, brought about by

42

out

DECK REPAIRS

literally levers

holes.

the deck

Another cause of starburst cracking is point impact, such as dropping an anchor or a heavy winch handle on deck. (Exterior like

impact may instead

the pattern of a target.)

result in concentric cracks

ELIMINATING THE CAUSE Backing plates. Starburst cracking can usually be stopped by

generous backing plates on the underside of the deck beneath the offending hardinstalling

ware to spread the

load.

Wooden

plates are the

easiest to fabricate, but stainless steel or bronze

are better because of their resistance to crushing. Bevel

the edges of the backing plate to

avoid causing a hard spot. Polished stainless steel plates with

threaded holes make for an

attractive installation.

Hard spots.

Stiffening.

Hard spots are more

common on the

hull

than the deck,

and usually appear where bulkheads attach. Stress cracks around hard spots are likely to return unless you eliminate the hard spot. This typically involves detaching the offending

fixture,

then reattaching

the work required

bulkhead

is

around cockpit

soles,

can

be prevented by stiffening the area with additional laminates. Laminating instructions are provided in "Laminate

some material from the edge, mounted on a foam spacer. Realistically,

strength, which translates into laminate thickness; use

may exceed

fiberglass

shaving it

Stress cracks related to general laminate weakness, such

as those that too often appear

the benefit, but anytime a

detached or a new bulkhead

is

installed,

Repair." In this case

mat

you are trying to add

stiffness,

not

to quickly build additional thickness.

it

should always be mounted with a foam spacer.

STRESS CRACKS >-

43

REPAIRING THE CRACKS Cracks layer,

in

the deck typically affect only the gelcoat

and perhaps the

first

layer of

mat beneath

the gelcoat. Repairs are identical to scratch repair detailed

in

may need

the previous chapter, except that you to

remove deck hardware to get

full

access to the damage. Occasionally flexing has

Gain access to the entire length of the crack.

been so severe that

woven

fabric of the laminate.

the strength of the laminate

with gelcoat paste.

'^l

44

DECK REPAIRS

extend into the

When

is

this

is

the case,

compromised, and

the area must be ground out and relaminated to restore

it.

repair are

Detailed instructions for this type of

found

in "Hull

Repairs."

Open the

crack with the corner of a cabinet scraper.

Sand and

buff.

1

Fill it

stress cracks

VOIDS Voids are thankfully rare in the flat expanses of

common

in

when

first

the

hull lay-up,

but

all

too

fiberglass decks. Voids occur layer of cloth

is

not com-

pressed against the gelcoat (or

subsequent laminate

is

when

a

not compressed

against the previous one). They are often as

much

a

consequence of design

as of work-

manship. While crisp angles and corners look

stylish,

they are more

may

mold

difficult to

with glass fabric. The fabric resists being forced into a tight corner and after saturation

may take

a

more

from the gelcoated mold. The void

—

result

is

a

pocket of air beneath the thin

a

gelcoat, perhaps "bird caged" with a

random

strands of glass.

pressure like

away

natural shape, pulling

is

The

first

few

time

applied, the gelcoat breaks

away

an eggshell, revealing the crater

beneath.

Deck voids are a cosmetic problem and

Break away the cracked gelcoat to

easily repaired.

Use

a rotary

grinding point chucked

in

your

drill

to

grind the interior surface of the cavity. Chamfer the

gelcoat

all

fully

expose the void.

1

Clean the cavity with acetone. For a better bond,

wipe the cavity with styrene.

around the void.

VOIDS

>-

45

Fill

the cavity to the bottom of

the gelcoat with a putty

made

and

from polyester

resin

chopped

Be sure you use

glass.

laminating resin.

resin,

Epoxy

is

not finishing

not recom-

mended because you

are going

to finish the repair with a layer of gelcoat,

and gelcoat does

not adhere as well to epoxy as to polyester.

When

the patch hardens,

fill

the remaining depres-

sion with gelcoat, overfilling slightly. Roll a piece of plastic into

the repair and seal the edges with tape.

When the gelcoat cures, sand

it

flush

with the surrounding surface and buff it

with rubbing

the gloss.

46

>-

DECK REPAIRS

compound

to restore

CRAZING (ALLIGATORING) Crazing, sometimes called alligatoring, is a random pattern of cracks that, at its worst, can cover the entire surface of a fiberglass boat

deck and flexing

hull.

There are two primary causes:

and excessively thick gelcoat.

the culprit, the crazing

will

to be successful, stiffening

deck

in

be

If

flexing

is

localized. For a repair

must be added to the

the area where the crazing has occurred.

Fortunately the is

— both

more common cause

of crazing

gelcoat thickness (or occasionally gelcoat

formulation). As the hull heats

and

expands and contracts. A thin

layer of gelcoat

cools,

accommodates these changes, but not reinforced

like

it

thick gelcoat,

the underlying laminates, tends

to crack. In this case, the crazing extensive. That's the

is

likely

to be

bad news; the good news

is

that the repair doesn't require any structural alterations.

mi

LOCALIZED CRAZING

Stiffen

1

the crazed area. See "Core Problems" for

alternatives

and step-by-step

instructions.

CRAZING

5>

47

Trace each crack with the corner of a cabinet scraper, or

if

the pattern

is

too

fine,

with a 36-grit sanding disk. Stop

grind the area

when

the disk

begins to break through the gelcoat; don't grind

al

the gelcoat away.

Paint the cracks or

ground area with color-matched

gelcoat paste. Seal the surface to cure.

48

>-

DECK REPAIRS

let

the gelcoat

Fair

the

a gloss.

new

gelcoat by block-sanding, then buff to

WIDESPREAD CRAZING Sanding and polishing surface-applied gelcoat is

worthwhile

when

relatively small

good

the

and the

condition, but

original gelcoat

is

new

gelcoat area

the gelcoat

rest of

when

is is

in

the majority of the

damaged, the labor

intensive

nature of gelcoat application suggests a different

approach. The best alternative entire

deck with

Remove

1

ble.

as

a two-part

is

painting the

polyurethane paint.

much deck hardware and

The quality of your

trim as possi-

refinishing job

is

directly

—

how much hardware you remove how unobstructed the deck is when you apply the paint. related to

i

Clean, degrease,

and dewax

all

the

smooth surfaces of the deck. (Nonskid surfaces are restored

in a

Sand the gelcoat thoroughly with paper and wipe

it

1

20-grit sand-

dust-free with solvent.

separate

process.)

CRAZING >

49

Mask nonskid

surfaces

elected not to remove.

and any hardware you have

Paint the

sanded gelcoat with

a high-build

primer. Apply the primer with a

coats are generally necessary to porosity;

foam fill

all

epoxy

roller.

Two

crazing and

machine sand each coat with

1

20-grit

paper.

Paint the primed surfaces with

two coats of two-part

polyurethane, following the manufacturer's instructions for rolling and/or brushing the paint. For

plete instructions

on repainting decks

other boat surfaces

book

50

>-

DECK REPAIRS

series.

— and

— see Sailboat Refinishing

com-

all

in this

RENEWING NONSKID you paint the smooth surfaces of the deck, you

will

probably want to

refin-

If ish

the nonskid surfaces as well. Painting nonskid surfaces tends to reduce

their effectiveness.

Always

refinish

You can

by adding

grit to

the paint.

the textured sections of the deck after the smooth portion.

There are two reasons for a

easily offset this

this order. First,

the nonskid surface

darker color than the smooth surfaces, and

with a darker one than the other

done on the textured

surface,

it

it is

easier to cover a lighter color

way around. Second,

will

almost always

is

if

the

be hard to get a sharp

masking

final

line

is

between the

two. Prepare textured surfaces for refinishing before painting the other parts of the deck.

ENCAPSULATED GRIT Scrub the nonskid

1

thoroughly with a stiff

brush, then use

terry cloth

— sec-

tions of old bath

towels

— to dewax

the surface. The

rough surface of the terry cloth penetrates the craggy

nonskid.

You

can't sand the bot-

tom

surfaces of the non-

skid,

but abrade

it

with

coarse bronze wool, using short, quick strokes. Fortunately

most of the

new

on the

stress

paint will be

on the

top surface, which you can sand with 120-grit paper. Flood the surface

and brush-scrub then

let

it

it

again,

dry.

RENEWING NONSKID

>-

51

— After the

smooth

surfaces are

painted and dry, mask them at the mold line of the nonskid.

Mix a nonskid paint additive into the paint and

on with

a

reason to This

is

medium-nap "tip

roller.

(There

is

roll

it

never any

out" the paint on a nonskid surface.)

the easy

way to

introduce

but because the additive

grit into

the paint,

— usually polymer beads

tends to settle to the bottom of the paint

tray, dis-

persion of the grit on the painted surface can be irregular.

For a

more

aesthetically pleasing result,

first

coat the nonskid area with an epoxy primer and

cover the wet epoxy with gers or a large shaker.

sweep

off the grit that didn't

on another nonskid that remains with

52

grit sifted

from your fin-

When the epoxy

area),

two

DECK REPAIRS

kicks,

gently

adhere (you can use

and encapsulate the

rolled-on coats of paint.

it

grit

RUBBERIZED OVERLAY For the best footing, you

may want to

consider a

rubberized nonskid overlay, such as Treadmaster

good choices

or Vetus deck covering, also

for

M

com-

worn-out nonskid textures. For

pletely hiding old,

overlay application, carry the paint V2 inch into the

nonskid area

when you

paint the deck.

Preparing the surface. Eliminate all molded texture. Most

of

can be quickly

it

taken off with a disk sander and a 36-grit

disk. (A belt

sander can also be used.) Be careful not to get outside the textured area. desirable to grind

away all the

depressions with epoxy putty.

sand the surface to

fair

It is

pattern.

When

the sander

Fill

the remaining

the epoxy cures,

and prepare

it

let

neither necessary nor

it

for the adhesive.

Cutting patterns. /

Make

1

a pattern

from

oversize, then place

cut

in

kraft it

on deck to trace the exact

the center of the paper to hold

it

lid

leave at least

between adjacent

nonskid and

1

inch

rails,

avoid confusion

A

in

place.

Use

Tape across holes

a flexible batten to

Jff

draw

uniform corners. For appearance and drainage,

curved edges, a can

for

outline.

coamings, or cabin

when you

sides. Write

cut the overlay, and

ll\

between the

panels, at least twice that

u

"TOP" on the pattern to

draw

a line

on

it

parallel to

\

°

paper for each of the nonskid panels. Cut the paper

//

i\i

"^Wx |\\\ TOP

\\\

[Wm ^yL^\\

the centerline of the boat, with an arrow toward the bow.

1

ICmlK ["ivA Do

not cut patterns for only one side, expecting to reverse

them

for the

opposite panels. Boats are almost never symmetrical, and hardware to be

in different locations.

Cut a separate pattern for every panel.

the patterns have been cut, tape effect before proceeding. Trace

them

all in

certain all

place and evaluate the overall

around each pattern with

the deck area to be coated with adhesive.

is

When

a pencil to outline

1^

RENEWING NONSKID

i-

53

Cutting the overlay. Place the patterns topside

1

ial.

Position

down on

the back of the overlay nnater-

the patterns on your material to minimize the waste

all

before making any cuts. Depending on the overlay you have chosen,

it

may be

necessary to align the patterns; use the line you

drew on eaCh pattern

for this purpose, aligning

it

parallel to the

long edge of the sheet of material. Trace each pattern onto the overlay.

Cut out the pieces with

tin snips or

heavy

scissors.

Applying the overlay.

on

Pick

the deck and press

flat,

putty knife, and clean

adhesive, glue the nonskid to

beginning with pressure

the deck with thickened epoxy.

the middle and working

dampened

Coat both the outlined deck

outward to

applying each section

the overlay manufacturer

area and the back of the nonskid with the adhesive, using a

serrated trowel.

54

up any squeeze-out with

Position the nonskid

doesn't specify a different

If

1

>>

DECK REPAIRS

all

it

edges.

in

residue with an acetone-

until

all

cloth.

Continue

are installed.

a

away the

in

turn

TEAK DECKS CLEANING Left untreated, good-quality teak

would normally weather to an

attractive ash gray, but the assault of

turns bare teak nearly black. Clean

does the job.

Start with a

it

modern-day

air

pollutants

with the mildest cleaner that

75/25 mixture of liquid detergent and

chlorine bleach (no water), boosted with TSP. Apply this with a brush, scrubbing lightly with the grain. Leave the mixture

wood dirt,

for several

stiff

on the

minutes to give the detergent time to suspend the

and the bleach time to lighten the wood, then

rinse

thoroughly

by flooding and brushing.

LIGHTENING As good as chlorine socks,

it's

you need

is

at bleaching cotton sweat-

not a very effective oxalic acid.

wood

You can get

bleach. For that

by buying a

it

commercial single-part teak cleaner the active ingredient

in

most

— oxalic acid

is

— or for about one-

tenth the price you can buy a can of Ajax house-

hold scouring powder. Whichever you select, brush

the cleaner onto wet teak and give

then scrub the

wood

it

time to work,

with Scotchbrite or bronze

wool. (Never, ever, ever use steel wool aboard your

boat

—

it

will

leave a

trail

of rust freckles that will be

impossible to remove.) Oxalic acid dulls paint and fiberglass, so

before you

wet down surrounding surfaces

start,

and keep them

Rinse the scrubbed

wood

free of the cleaner.

thoroughly; brushing

is

essential.

For potential treatments for teak decks, see

Boat Refinishing

in this series.

TEAK DECKS

>-

55

TWO-PART CLEANERS Two-part teak cleaners are dramatically effective restoring the color to soiled, stained,

at

and neglected

teak, but these formulations contain a strong

acid

— usually hydrochloric — and should only be

used

when

all

other cleaning methods have

Wet the wood

1

to be cleaned, then use a nylon-bristle

brush to paint part

1

onto the wet wood, avoiding

contact with adjoining surfaces. bristle brush, is

I

failed.

the cleaner

will

If

you use

a natural-

dissolve the bristles;

it

doing the same thing to your teak.

Scrub with the grain.

Part 2 neutralizes the

acid in part

usually has

1

and

some

cleaning properties. Paint sufficient part 2

onto the teak to get

a

uniform color change.

Scrub

56

>-

DECK REPAIRS

lightly.

Flush

away

wood

dry.

a//

traces of the cleaner

and

let

the

SURFACING After a

number

of years, bare teak decks

This unevenness traps dirt

become rough and

and harbors mildew, making the deck

harder to clean and harder to keep clean. The solution the deck with a belt sander, using a

moving

at

all

times,

ridged.

and sand

at

1

20-grit belt.

about

1

5° to

is

to resand

Keep the sander

the grain.

RECAULKING The

instructions that follow are for recaulking a sec-

tion of a single seam, but the steps are the

same

for

an entire deck.

With a razor

1

knife, cut

the seam caulk at a diagonal a

couple of inches beyond the bad section, then

slice

the section to be replaced free from the planks on either side, taking care not to nick the

wood.

Dig out the old caulk. This

made by about

heating the

90°.

planks,

When

tail

every

vacuum the

is

of a

bit of

much file

easier with a rake

and bending

the old caulk

is

it

off the

scrapings out of the seam.

TEAK DECKS

>

57

A

Use an acid

Mask the

sur-

brush or a

face of the

Q-Tip to

planks.

thoroughly

prime both plank edges.

Use the primer

recommended for the caulk

you are using.

Two coats are generally required.

The

"right" caulk for

deck seams

is

two-part polysulfide. Mix the catalyst

into the sealant per label instructions, taking care not to introduce bles,

then

fill

an empty caulk tube with the mixture. (For limited

a single-part polysulfide will also give

good

convenient.) Cut the tip of the tube and

When the entire seam into the

is

seam by dragging

IDENTIFYING DECK CAULKING FAILURE HOW DO YOU KNOW WHEN THE SEAM caulking on a teak deck has released

its

grip

on the wood? The wood usually tells you. On a sunny day, scrub the deck, then keep it wet for half an hour or so before letting it dry. Areas along the seams that stay wet longer than the rest of the deck are suspect; spots that stay dark a

lot

longer definitely

indicate caulk failure. Using the point of a knife,

you

will

see that you can separate the

caulk from the wood, and the

plank

will

be wet. Repair

before they result

in

edge of the

"flagged" seams

bigger problems

beneath the teak.

58

all

DECK REPAIRS

the seam from the bottom.

a putty knife over

Remove the masking

knife,

but

it

repairs,

and may be more

slightly overfilled with sealant,

hump up slightly behind the cures.

fill

results

bub-

will

it

firmly.

compress

The sealant

it

will

shrink almost flush as

carefully while the caulk

is still

tacky.

it

BUNG REPLACEMENT The most

common problem

popped bungs. Years

of teak decks

Just tapping a

is

of scrubbing thins already-

thin overlay planks until the grip of the

bungs

is

new bung

rary repair at best. cial

in

place

will

be

a

tempo-

Deck overlay bungs require spe-

procedures.

insufficient to hold against flexing or expansion.

Remove and rebed the screw

1

in polysulfide.

Deck

core problems often occur beneath teak overlay

because the screws holding the overlay penetrate the top skin of the deck. Always rebed exposed screws.

It is

a

good

idea to check the core for

sponginess with a piece of wire. (See "Core Problems.")

•^

Reduce the plug bevel.

In a

shallow hole, you

Use a Q-TIp to wipe both the hole and the plug with

cannot afford the generous bevel found on most

acetone to remove surface

commercial teak plugs; sand the bottom of the plug

install

to reduce

it

to the bare

oils.

Wait 20 minutes to

the plug.

minimum.

TEAK DECKS

-j^

59

—

COLLOIDAL SILICA (FILLER)

Mounting

a plug

permanently

in a

After the

shallow hole

epoxy

is

dry, place

the point of a chisel

down — against the

plug about Vs inch

requires the tenacious grip of epoxy glue. Paint the

beveled side

hole and sides of the bung with unthickened epoxy.

above the surface of the plank and tap the

chisel

Thicken the epoxy to catsup consistency with

with a mallet. The top of the plug

away.

(colloidal silica)

plug. will

will split

and coat the sides of the hole and

Tap the coated plug

go.

filler

into the hole as far as

Wipe up the excess

it

glue.

Working from the lowest edge of the trimmed plug, pare

away the plug

until

it is

nearly flush with the plank. Finish

the job by block sanding the plug with paper.

60

>-

DECK REPAIRS

1

20-grit sand-

PLANK REPLACEMENT Occasionally a teak plank splits or

damaged and

is

otherwise

requires replacennent.

More often

teak overlay problems have an underlying cause usually a

wet core

— and to effect repair the teak

must be removed. Since the cause of the leakage

some

boat-

elect not to replace the overlay, but

most

often turns out to be the screw holes,

owners

are unwilling to give

teak decks.

A

up the beauty and footing of

careful installation minimizes the risk

to the core.

If

1

you are replacing more than

ber and Crosshatch

all

a single plank,

num-

the planks to be removed so

you can put them back properly.

/

J 9

[i^

—

r

\

1 I

'i:',";i;';'i!:'.i',i' iM/i'', With bungs removed (carefully

if

you

will

be reusing the

the screws. Slice the plank free of the caulking

all

plank), extract

around, and pry the

plank up from the bedding compound, using a block under your prying tool to protect the adjacent plank.

organic it is

compound,

bedded

should slowly

in polysulfide,

plank to remove rest of

it

it.

you are

If

the plank

pull free

likely

—

is

like a

bedded

an

in

gum-stuck

to have to destroy the

heel.

If

first

With side access, you should be able to separate the

the planks from the deck with a thin, sharpened putty knife. A

length of steel leader wire connected to two lengths of dowel

times effective

in

is

some-

"cutting" deck planks free.

TEAK DECKS

>

61

Scrape and sand away

all

old bedding connpound.

If

the core

is

dry, protect

of epoxy. Give the

epoxy

it

a

by injecting the hole

full

few nninutes to saturate

the edge of the core, then draw out the excess with a small

brush or a

stick.

For greater security,

drill

each hole oversize and, after painting the sides with unthickened epoxy,

ened with redrill

62

>-

fill

each hole with epoxy thick-

colloidal silica.

When the filler hardens,

the center for the screw.

DECK REPAIRS

If

you are

installing

new

planks,

fill

holes with epoxy putty, but don't

the

new

plank Into position, then

the deck. Counterbore the hole

in

half the plank's thickness but not thirds.

Epoxy the new holes

two methods just

detailed.

in

the old screw

redrill drill

them.

Wedge

the plank and

the plank at least

more than two-

the deck

in

one of the

Wash the deck and the underside

of

the plank with acetone. For better adhesion, prinne the teak. Coat the

deck with black polysulfide (two-part preferred) a

Hold or

down.

much

wedge the

plank

in

position

Select Philips-head screws less likely to

and screw

and you

damage the edge

will

of the

and

distribute

it

evenly with

saw-toothed spreader.

it

be

bung

hole with the screwdriver.

8

Install

bungs (with epoxy) and trim

them. Caulk the seams.

Belt

sand the

deck fair.

TEAK DECKS

5>

63

64

LAMINATE REPAIR

The

and deck

hull

— problems that can be fixed with a proper topical applica-

leak related

tion of

have either been cosnnetic or

repairs described so far

one glop

or another. But

sometimes the problem

is

below the

face: the original laminate lacks the requisite stiffness; moisture has

integration or delamination; or the glass fibers have

These problems require more extensive Fiberglass has of

its

of fiberglass boats.

healed with a

And the

it is

repair

is

repair.

repairability that

less

can of

patch than graft

material because

accounts for the near immortality

The most horrifying hole

bit of glass fabric, a

dis-

been broken by impact.

become the predominant boatbuilding

durability, but

caused

sur-

in a fiberglass hull is

resin,

and equal parts

quickly

skill

and

care.

— a new piece of skin indistinguish-

able from the old. Fiberglass lay-up can hardly be simpler.

It is

nothing more than layers of

glass fabric saturated with polyester (or epoxy) resin. With a paint brush, a

of water,

and

a piece of old T- shirt,

you can practice

all

the requisite

skills

cup for

fiberglass lay-up.

Don't misunderstand: because of blocked access or complex shape, lami-

nate repair cannot always be honestly characterized as easy, but such problems

what make most boatowners shy away from attempting a repair. It's the lay-up. Most boatowners imagine a self-applied laminate as only slightly more

aren't

durable than a wet Band-Aid. That

provided

in this

chapter

what you can expect

is

a false concern. Follow a

— and your lay-up

a yard to do.

And

it

will

will

few simple

rules

be as good as or better than

remain that way a decade

down

the road.

65

UNDERSTANDING POLYESTER RESIN Polyester

resin

is

the glue that binds glass fibers

into the hard substance

we

call fiberglass.

On

the other side of the Atlantic, the same product

— glass-reinforced

called

GRP

British

take

plastic.

is

As usual, the

more care with the language than we is exactly what it is.

do; glass-reinforced plastic Polyester resin, plastic

when

— not one of those tough plastics that

deflects bullets or that 1

catalyzed, hardens into

00 years

you can use as

a

hinge for

— but an amber-colored, rather seems more

plastic that

building material. But

like

when

brittle

combined with

sum

is

greater

than the parts. Polyester resins

come

in

(see sidebar), although

you

kind a particular brand

is

various formulations can't always

from the

priate for the repair

what

tell

label. Generally,

you don't need to know. When polyester (sometimes epoxy

is

appro-

resin

is

a

better choice), whatever laminating resin your

supplier carries should prove satisfactory. Below-

the-waterline repairs are the exception; avoid

rock candy than boat-

ortho resins

polyester resin

immersed.

is

glass fibers, the

if

the repair

will

be continuously

LAMINATING VERSUS FINISHING You do need to choose between laminating and fin-

1

ishing resin. Laminating resin

is

"air-inhibited,"

ing that the resin will not fully cure while air.

That

may sound

solidifies

mean-

exposed to

odd, but remember that polyester

not by drying,

like paint,

but by a chemical

reaction (called cross-linking) induced by adding a catalyst. Air interferes

with this curing process.

For any job that requires the laminates to be

applied

in

more than one operation, you need

lami-

nating resin. The fact that the surface remains tacky after the resin sets allows

you to apply the subsequent

laminates without any intermediate steps, and the

new application will one to form surface

a

link

chemically with the previous

LAMINATING

powerful chemical bond. For a tack-free

on the final

RESIN

application, coat the resin with

polyvinyl alcohol (PVA) or seal

it

.

AlRlNHlBlTfc'^

with plastic wrap.

Finishing resin

is

identical to laminating resin, but

with an additive that "floats" to the surface of the curing resin. This surfactant (once wax, but ally a

drying

oil)

seals the resin

from the

air,

now

usu-

thus

allowing the surface to fully cure to a tack-free,

•FINISHING ,„^ . '^'IR

66

>>

RESIN

NOT INHIBITED

sandable

state.

Use finishing

done

in a

be used

resin for laminate jobs that

can be

single operation. Finishing resin can also

for the final layer of a multilayer lamination.

LAMINATE REPAIR

I

r ORTHO,

ISO,

OR VINYLESTER?

FOR THE FIRST 30 YEARS OF FIBERGLASS BOAT MANUFACTURING, the only resin widely in use was orthophuntil fiberglass boats thalic resin. Ortho resin was cheap, easy to work with, and had no apparent failings

—

began to

blister.

Isophthalic resin, slightly it

more expensive, has largely replaced ortho resin in boat nnanufacturing because due to its higher solvent resistance. A packaged polyester resin sold

seenns less prone to blistering, probably

for repair work,

good

if it is

Vinylester has long

resistance, but

turers hulls.

its

be iso resin. performance boats because of its superior adhesion qualities and impact

quality, will likely

been used

in

superiority as a moisture barrier has led to

now use vinylester laminating

resin

and

more widespread

use.

Many new boat manufac-

produce

vinylester gelcoat in theii quest to

For repair work calling for polyester resin, vinylester's better adhesio. makes ,

it

a

blister-resistant

good

choice.

I. HOW MUCH The

CATALYST?

catalyst for polyester resin

MEKP

not confuse

with the

is

methyl ethyl ketone peroxide, or MEKP. Do

common

Polyester resin usually requires

low the manufacturer's ener

will

catalyze

1

solvent MEK; they are nof the same. to 2 percent of hardener by

1

ounce of

resin at

thoroughly or part of the resin

will

1

percent. Be certain to

weather, and the thickness of the laminate is

is

(fol-

the catalyst

all

less catalyst.

just as

of too

little

weak

lamination.

catalyst;

good \f

in

affect curing times.

about two hours

unless the wait

will

you add too much, the

is

probably

in

lay-up.

Temperature,

Some

experi-

generally required. The mix shouldn't kick (start to harden)

than 30 minutes. Hardening overnight

stir

be undercured, weakening the

You can adjust the cure time by adding more or mentation

volume

As a rule of thumb, four drops of hard-

instructions).

ideal,

in less

but

hold you up. Always err on the side resin will "cook," resulting in a

FIBERGLASS MATERIAL Fiberglass material

weave repair,

ing,

is

exactly

what

it

sounds

of glass fibers. For boat construction

the glass comes

and

cloth.

in

like,

a

and

chopped-strand mat, rov-

Chopped-strand mat. Chopped-strand mat is made up

of irregular lengths of

glass strands glued together randomly. Generally speaking,

CSM

the easiest fabric to shape, gives the best

is

resin-to-glass ratio, yields the

most watertight, and

is

smoothest surface,

is

the

the least subject to delamination,

but the short fibers do not provide the tensile strength of a

woven Mat

material. is

sold by the yard from a

ous weights designated

ounce mat

is

a

in

roll

and comes

ounces per square

good choice

in vari-

foot;

1

Vi-

for general use.

UNDERSTANDING POLYESTER RESIN

>-

67

-;:^;^^::^M^

Fiberglass cloth. Fiberglass cloth looks like shiny canvas but not tightly. Cloth

is

stronger for

its

prone to pulling and unraveling process,

Roving. Roving

parallel, flat

is

bundles of continuous glass

unwoven roving

stitched together;

parallel

in

straight,

in

woven

in

unwoven

roving

is

usually a better choice because

strength

in

two

full

strength

in all directions.

is

directions

is

a better choice for

commonly available

any, fiberglass

the direction of the strands but

roving

provides

Cloth

ounces. For any boat over

continuous strands

strength perpendicular to them. For hull and deck

repairs,

better.

While

most

repair work.

woven roving assembles the bundles

add excellent strength little

the laminating

and the finished product looks

and roving, mat and cloth

bundles are cross-

directions in a loose weave.

The

in

1

in

weights from 4 to 20

5 feet, there will

be

work that you cannot do with

mat and 10-ounce

cloth.

If

you have

1

a choice,

little, if

V2-ounce

buy 38-

inch width. it

and good

(You can accomplish the same

thing by rotating the orientation of alternating laminates of

unwoven

strength

roving, but unless

you need additional

in a particular direction,

using

woven

roving

is

OTHER MATERIALS

simpler.)

Roving laminated to roving, either unwoven or

woven,

is

unacceptably easy to peel apart. Always bind

layers of roving together

by using a layer of mat between

For most repairs, select 18-ounce roving. That

sound heavy

relative to

I

GLASS I5NT THE ONLY MATERIAL THAT CAN be combined with

resin. Increasingly,

1

may

V2-ounce mat, but don't be con-

Weight designations

for

mat

are per square foot,

while for roving (and cloth) they are per square yard;

ounce roving weighs the same

as 2-ounce mat.

1

8-

composites with special characteristics weight, rigidity (or flexibility), impact

als

include graphite (carbon

None of these deck

repair.

a material's strengths

you use

k LAMINATE REPAIR

light

resis-

fiber), Kevlar,

polypropylene, xynole-polyester, Dynel, and

cal hull or

>-

—

tance, tensile strength, or others. These materi-

ceramic.

68

boat-

builders are using "exotic" materials to create

each layer of roving.

fused.

as

less

manufacturers generally use alternating layers of mat

strands. In

two

woven

weight than roving,

it.

is

essential for the typi-

You should understand and weaknesses before

GRINDING During the lay-up form

IS

ESSENTIAL

process, each application of resin links chemically with the previous application to

a solid structure

— as though

deceiving; a better analogy

all

the layers were saturated at once. The layer-cake look of fiber-

Jell-0 salad

— the

may be

glass

is

solid.

Chemical linking between resin layers occurs because each layer

fully

is

cures (the reason for using air-inhibited

Unfortunately, no matter

how strong the

fruit

in layers, is

but the encapsulating Jell-0

applied before the previous one

resin).

laminate-to-laminate bond, the

initial

mechanical, not chemical. This need not weaken the repair as long as the surface

means

is

is

bond of any

repair

is

properly prepared. That

grinding.

Before grinding, always wash the area thoroughly with a dewaxing

1

solvent.

The

original fiberglass will

have traces of mold release on

the outer surface and wax surfactant on the inner surface. to

remove the wax

first,

surface scratches and

grinding

will

drag

it

into the

If

you

fail

bottom of the

weaken the bond. Protect your eyes

with goggles and

your lungs with a

good dust mask. A paper mask is inadequate for

all

but

the smallest grinding task. will

Long sleeves

reduce skin

irritation.

Outline the area of the

loaded with a 36-grit

bond and grind

disk. Tilt

inside the outline with a disk sander

the sander so that only one side of the disk

touching the surface and the dust

is

is

thrown away from you.

Brush away the dust and wipe the area with an acetone-dampened rag. The surface should have a uniform dull look;

if

any areas remain glossy, make

another pass over them with the sander.

GRINDING

IS

ESSENTIAL

'^

69

THE BASICS OF FIBERGLASS LAY-UP PREPARATION

Dewax and

1

applied later

grind the surface the lay-up

to. Specific

types of repairs

will

be

— detailed

— require additional surface prep.

Protect

all

surrounding surfaces by masking.

Waxing below the

repair area will

make

unantici-

pated runs easier to remove.

--

^^

-^-^i^^Mm^^^^

Cut the fiberglass pieces to the correct

them out

in

the order you

will

a rule, apply the smallest piece last.

70

>-

LAMINATE REPAIR

Always

start

and

finish

size

and

lay

be applying them. As first,

the largest piece

with mat.

APPLYING THE INITIAL LAYER

Catalyze the resin and mix

it

Hold the

thoroughly.

1

line

first

around

layer of fiberglass in place

It.

and

pencil a

Use a throw-away brush to coat the

outlined area with resin.

Apply the

first

layer of

a vertical surface, use fabric in place.

and press

it

Use

a

mat

to the wetted surface.

On

masking tape to help hold the

squeegee to smooth the mat

into the resin.

With a brush or a it is

roller,

wet the mat with

resin until

uniformly transparent. White areas are dry spots

and require additional

resin.

Brush or

roll

gently to

avoid moving the fabric or introducing bubbles.

THE BASICS OF FIBERGLASS LAY-UP

71

ADDITIONAL LAYERS

Apply the next layer

1

the saturated mat.

— cloth or roving — on top of

Smooth

it

against the mat with a

Wet out the grooved any

squeegee.

air

cloth with resin. Use a

roller

to

squeegee or

a

compact the laminates and force

bubbles to the surface. Remove excess

resin

with the squeegee.

If

the weather

is

cool or the repair area

is

can apply up to two more layers without cure generating so

much

heat that

or warps the repair.

72

>-

LAMINATE REPAIR

it

small, risk

you

of the

cooks the resin

Allow the resin time to apply two

(or

process until

gel,

then mix fresh resin and

more) additional all

layers,

repeating this

the layers have been laminated.

FINISHING For a smoother

1

finish, roll

After the last coat

an

of resin kicks,

additional coat

brush or spray on

of resin over the

an unbroken coat-

final layer of

ing of polyvinyl

material.

alcohol (PVA) to seal the surface so it

will

cure

This

isn't

sary

if

fully.

neces-

you use

fin-

ishing resin for

the

last coat.

WORKING OVERHEAD Alternative application

1

techniques are required to laminate fiberglass

overhead. Mix a small batch of

more

resin,

adding

catalyst than usual,

and use

it

to

wet the

repair area.

For an overhead repair, always work with small pieces of fabric. Roll the

mat onto

a

dowel or

a

cardboard tube, and wait for the resin to

edge of the mat and

surface feels tacky, carefully position the

keep

it

smooth. The tacky

fresh resin.

Use

a roller or

resin will hold the

squeegee to

mat

in

piece of

start to kick.

unroll

it,

When

the

taking care to

place while you saturate

it

with

distribute the resin.

When

the surface of the mat

the next layer of fabric onto

keep

it

Repeat are

first

smooth. Saturate this step for

is it,

tacky,

this layer

each layer

you can

unroll

again taking care to with fresh resin.

until

all

the laminates

in place.

THE BASICS OF FIBERGLASS LAY-UP

73

WHEN TO

USE EPOXY

Epoxy is almost always better than resin for repair

bond job

—

forms

it

worth the

work because the mechanical

— the weakest

stronger. Laminate

is

also superior

less significant,

polyester

link in

made

Do not use epoxy

any repair

with epoxy

is

is

more than twice

of polyester, manufacturers rarely use nating. For repair

it

if

polyester, the reverse

epoxy

for lami-

repair will not

for boatbuilding.

The

two most common brands are West System (Gougeon Brothers) and System Three, but there are others. The main difference you are likely to notice between competing brands

tend to make

the mix

is

ratio,

but metered

this difference of

pumps

consequence.

little

ADDITIVES For saturating fiberglass laminates, use the epoxy as

course

— but

bonding and

for

cific characteristics.

filling,

short fibers for small putty needs, but for fillers

are easy to mix, provide

Microballoons. Microballoons produce ily.

a fairing

comes

it

and

for filling

good

more than strength,

for

hull

and deck

it

spe-

repairs.

bonding where there

is

a

glass cloth diagonally to generate

that

buy packaged microfiber filler.

and have excellent finish

are tiny hollow beads of plastic.

compound, microballoons

— catalyzed, of

epoxy and give

Three of these are especially useful for

gap between the surfaces being bonded. You can snip

Fiber

it

additives thicken the

Fibers. Fibers added to epoxy will thicken

Added

yield a putty that spreads

to

properties.

epoxy to

and sands eas-

Microballoons reduce the strength of the epoxy and should not be used for bond-

ing or laminating. Also avoid using microballoons below the waterline because the resulting putty

is

porous and

Colloidal Silica.

Silica is

than microfibers and

it

will

absorb water.

perhaps the most versatile of fillers.

74

5^

It

provides better strength

doesn't affect the permeability of the cured epoxy.

thickened putty cures with a rough texture and

LAMINATE REPAIR

resists

is

will

be finished

not true; the bond

be gelcoated, use polyester

is

Don't buy epoxy by the tube.

epoxy formulated

the repair

be strong.

SELECTING EPOXY

Select an

well

between polyester gelcoat and an underlying

that

work the additional expense

is

with gelcoat. While epoxy bonds tenaciously to

— stronger and more durable — but

because the cost of epoxy

and the added strength

cost.

abrasion

Silica-

— including sanding.

If

the surface

will

resin for the repair.

MIXING Metering pumps. While polyester requires only a few drops of catalyst per ounce of resin to start the chennical reaction, the combination ratio for epoxy is much less one-sided. The resinto-hardener ratio

is

some formulations

typically at least five to one, but call for a

two-to-one mix. Epoxy man-

ufacturers typically have calibrated will

to

meter out the correct

one pump of

resin.

ratio

Epoxy

so the purchase of metering

mended. flat

Stir

mixing

is

pumps

available that

— one pump of hardener very sensitive to mix

pumps

is

ratio,

strongly recom-

the two parts together thoroughly, using a

scrape the sides, bottom, and corners

stick to

of the container.

Regulating cure time. Unlike polyester, the cure time of epoxy cannot be

adjusted by altering the fied proportion of

amount

of hardener.

—

./"'^

speci-

hardener must always be used.

However, epoxy manufacturers generally

two hardeners

The

fast

and slow

offer at least

— and they often have

additional hardener formulations for special require-

ments, such as tropical use. Pot temperature, but you

will

life

varies with

quickly learn

available. Limit batch size to the

ambient

how much

amount

of

time

is I

epoxy you

1

can use

in

that

amount

pot, so the quicker

to

work

of time. Epoxy cures faster

you apply

it,

the longer you

will

in

the

\

have

it.

W

Thickening. Always add the thickening agent after the resin and hardener have been mixed. Stir in

^^^tfrH

the thickener until the

®

\}

^= (D

^-x-^

^^^^ (-yr-

MICROBM

1

®

mixture reaches the desired consistency.

''

Y

WHEN TO

USE EPOXY

75

PRECAUTIONS People to

in significant

numbers develop

epoxy so that any exposure

tion

and

course.

Avoiding

rash.

Wear

all

a sensitivity

results in skin irrita-

skin contact

plastic gloves

the safest

is

when working

with

epoxy. Goggles are reconnmended.

Avoid breathing the fumes of curing epoxy. Be sure you have

good

ventilation.

The heat generated by curing epoxy to melt a plastic container

flames

if

you leave the mixture

—

until

sufficient

ignite into

the pot too long.

in

the mixture begins to heat up, put

from anything flammable

is

and may even

it

it

outside

If

— away

cools.

LAMINATING WITH EPOXY Do not use chopped-strand mat when

1

laminating

with epoxy resin. The binder holding the strands

may

together

react with the epoxy, affecting both

the adhesion and the permeability of the epoxy.

Epoxy

is

a strong

enough adhesive

cloth without risk of delamination,

to bind cloth to

and multiple

lay-

ers of fiberglass cloth create an extremely strong

laminate.

^?^