Owner’s Manual Page 105Fiberglass and Hull - Section P
Gel coat, like paint, will change colors with time
and exposure to sunlight (ultraviolet). For this rea-
son, “matching” gel coat obtained from Four Winns
may not match the gel color of a boat that has
been exposed. However, this is the closest match
commerciallyavailable.Aberglass/gelcoattech-
nician can tint the gel to be used in the repair to
provide a closer color match.
Moresevereberglassdamage,especiallywhen
structural, requires the expertise of an experienced
berglassrepairtechnician.SeeyourFourWinns
dealer for assistance.
NOTICE
Improper repair techniques can lead to further
berglass component damage.
C. Osmotic Blistering
Osmotic blistering or “boat pox” is an unfortunate but
notuncommonoccurrenceinberglassboats.Fiber-
glass is water retardant, not waterproof. When a boat
isleftinthewaterforaperiodoftime,theberglass
will absorb water. It is a natural process that can not
be eliminated in production methods or material selec-
tion and usage. However, there are ways to control
and possibly prevent blisters (see Section P-6). If you
do encounter blisters, be assured that the blisters are
merely cosmetic. They do not indicate a defect in the
boat structure or lamination. Four Winns, along with
most boat manufacturers, regard gel blisters as a
standard maintenance item.
The repair procedure for gel coat blisters is similar
to the procedures outlined in the previous section on
cracks and gouges. There is an exception however, in
that the hull must dry out for several days or possibly
weeks before repairs can proceed.
Todetermineifthehullhasdriedsufciently,tapeone
square foot of household plastic wrap securely to the
hull bottom. Make sure all edges are sealed and let it
stand for twenty-four hours. If condensation has ac-
cumulated under the plastic, the hull is still “wet” and
must be allowed to dry longer before repairing.
When the repair is completed, an application of an
epoxy barrier coat should be considered. This will help
prevent the possibility of reoccurrence of blisters. Your
Four Winns dealer or local ship store will have informa-
tion on barrier coat products.
structural integrity of the boat. In most cases, they are
cosmetic and can be treated. Cosmetic surface dam-
a
ge can be repaired as follows:
1. Sandthesurroundingareawithmediumornegrit
sandpaper. Clean all marine growth, dirt, antifoul-
ing paint, etc. from the immediate area. DO NOT
excessively scratch or gouge the surrounding area.
2. Use a hard, pointed tool to open the gel crack.
Take care not to damage the surrounding gel coat.
3. Sand the crack or gouge so the edges are smooth
and will allow proper “feathering” of the area.
4. Clean the area thoroughly. Make sure the area is
dry before proceeding.
NOTICE
Be sure the structure and the ambient tem-
perature are above 60 degrees F (15 degrees
C) and the relative humidity below 70%
immediately before, during, and after the
repair.
5. If the nick or gouge is deep and penetrates
throughthegelcoat,lltheareawithberglass
patching paste. Follow the directions on the can
when mixing the paste with the catalyst.
6. Afterthegougeislledandhasdried,sandthe
patchedarea.Beginbyusingmedium-negrade
sandpaper.Progressivelyusenergradesandpa-
per until the surface is very smooth. If necessary,
addllerandthensandthesurfaceagain.
7. Applytwoorthreelightcoatsofmatchingber-
glass gel coat to the repaired area. Enough gel
coat should be used so that the entire area is
covered.
T
he gel coat must be catalyzed using up to 2% MEK
Peroxide which can be purchased at a supplier han-
dlingberglassreinforcedproducts.ContactyourFour
Winns dealer for assistance.
8. After ample drying time, sand the area using very
newet/drysandpaper.Iftheappearanceofthe
area is still not satisfactory, repeat steps 2 through
8 as necessary.
9. If above the waterline, polish the area using a
berglassrubbingcompoundandthenwax.If
the repaired area is below the waterline, the area
should be primed and painted in accordance with
the antifouling paint manufacturer’s instructions.
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