bottom coat

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Chris - 27 Mar 2006 21:18 GMT

Its almost warm enough to consider working on my old boat again, and so I
have a few questions.

My boat is near 16ft, and fiberglass from the 70's (Sunray).

It has a severely faded green colored bottom (like pea soup green) given the
many years its been around in the sun. Underneath where the sun never gets
to, it obviously looks greener and better though.

I don't think its ever been painted, but rather the green is from the
original gelcoat.

It hasn't been waxed for probably over 18 years if ever, although 2 years
ago I tried rubbing a bit of a fancy product on it that was suppose to
restore the colour and treat any oxidization - but I didn't notice any
improvement.

I'm looking to repair a few small things in the fiberglass and then paint
the entire bottom side to give it a darker, richer colour, and ensure things
are sealed.

Now, my questions:

1. I'm looking for a bottom coat paint then correct? And this should be
antifouling?

2. I don't think I need to dewax the boat, as the weather should have burnt
everything off long ago.. it really looks worm, there can't be anything on
it. Do I just start painting?

3. Should I spray it, or apply the paint with a brush?

4. How much paint would it take to do a boat this size would you think?

It's an old boat, not a show boat and I don't have a large budget for it, so
I'm looking to do things the cheaper way.

any help is appreciated

Reply to this Message

Ron Magen - 28 Mar 2006 14:33 GMT

Chris,

'Faded' or not, the bottom color may NOT be the gelcoat. Either way,
especially if you have used some product on it, you WILL have to clean /
scrub / sand the bottom. No big deal - these are things you should do to
inspect & repair the bottom, anyhow.

I use denatured alcohol as my initial cleaner. WEAR GOGGLES and use a LOT of
paper towels. It's cheap enough {by the gallon at Home Depot - Paint
Department}and fairly innocuous. After a good scrub with the alcohol {if you
see color come off, or discoloration on the towels, it's probably NOT
colored gelcoat}, use a stiff brush and mild soapy water. Hose off & let
dry. At this point inspect the hull . . . WELL.

If all is OK, 'scuff sand' the entire bottom. Repair whatever needs to be
done . . . with EPOXY. There are several books on how to do almost any type
of repair.

'Sealing' and 'Painting' are actually two different things . . . if done
properly. First apply a 'barrier coat' . . . about 15-20mils. There are
specific products, or you can simply apply two or three coats of epoxy. Use
a brush for detail & edge work, and a roller for the large areas. The type
of 'Paint' you use depends on the waters you sail in, and the length of time
the boat spends in the water. At one end is the boat that is placed in a
warm salt-water environment at the beginning of the season, and removed
several months later. On the other end is the boat that 'lives' on a trailer
and is occasionally 'dunked' in a freshwater lake or river. 'Warm salt'
equals an anti-fouling with a high concentration of biocide. The other could
get away with a good acrylic enamel {or Marine 'topside' paint} that has had
at least 14-days to cure before use.

A 16-foot boat probably has a water line of maybe 14-feet. Either way, a
quart of paint should give you two coats. The epoxy WILL be more expensive,
but it is only done ONCE, and it's nice stuff to have around the house.
Besides, the bottom, under the paint, is the part you don't see . . . until
there is a catastrophic failure.

Regards & Good Luck,
Ron Magen
Backyard Boatshop

> Its almost warm enough to consider working on my old boat again, and so I
> have a few questions.
[quoted text clipped - 34 lines]
>
> any help is appreciated

Reply to this Message

Chris - 28 Mar 2006 16:05 GMT

Fantastic Information Ron,

Yes, My boat will be in the fresh water occasionally and otherwise sit on a
trailer.

I'll look for some of that denatured alcohol you mention to start my
cleaning. Do you know if it damages silicone?

My hull has some cracks in it that I plan to fix. I have used Epoxy before
for other repairs and plan to do the repair with that rather than poly
fiberglass.

Based on my use of epoxy before I'd think using the epoxy for a barrier coat
would be pretty costly wouldn't it? We're talking the same epoxy that I use
for repair, just without any filler, or mat right - liquid only? How much
of that would you think would be required? Far less than for general
repairs?

Finally for a paint I guess I could use a good acrylic enamel or topside
paint if I find the right colour.

Thanks
C.

> Chris,
>
[quoted text clipped - 91 lines]
>>
>> any help is appreciated

Reply to this Message

Chris - 28 Mar 2006 16:54 GMT

To clarify,
Would I use regular epoxy resin? like e.a.s.t-or..w.e.s.t
or are we talking an epoxy paint?

> Fantastic Information Ron,
>
[quoted text clipped - 121 lines]
>>>
>>> any help is appreciated

Reply to this Message

Chris - 28 Mar 2006 17:12 GMT

such as an interlux epoxy sealer paint as those made by w.e.s.t versus boat
building epoxy resin?

> To clarify,
> Would I use regular epoxy resin? like e.a.s.t-or..w.e.s.t
[quoted text clipped - 129 lines]
>>>>
>>>> any help is appreciated

Reply to this Message

Ron Magen - 28 Mar 2006 23:00 GMT

Chris,

First - in speaking about 'protection' DON'T 'think cheap'. YES - shopping &
researching for the best deal and a product specific to the task is prudent.

There are products SPECIFICALLY designed for 'Barrier Coats'. These are
'task specific'. While not necessarily cheap, they are less costly then an
equal volume of WEST epoxy. Epoxy - no matter which GOOD brand {I use RAKA}
is a 'multi-task' item. While I get my epoxy in 3-gallon 'batches' {which I
find is a good balance for use & economy} you only have a 16-foot boat and
no 'future plans' for other epoxy uses. With that in mind, also remember
that you are doing repairs, then coating, a relatively 'non-absorbing' hull.
Rather then having to 'fill the pores' on a wood hull, then saturate the
cloth sheathing, you will only be 'painting on' a couple of coats of
'finish'.

Buying epoxy, or 'barrier coat', or good paint by the single quart is the
most expensive way to do it. If memory serves, good paint and un-filled
epoxy {as a 'finish coat'}will give about 400 sq.ft. per gallon. A 16-ft
waterline with a 5-ft beam is about 120 sq.ft. {While you are doing whatever
it s that you are doing, I'd add 'striking a waterline' and painting or
taping a 'boot top' to my list.}In this case 'More IS Better' - 3 coats will
be about 360 sq. ft. You should have more than enough left to do this after
the repairs. WEST is NOT 'cheap stuff', but readily available. Other brands
may seem cheaper . . . however, remember to add the shipping for a single
gallon 'kit'.

I'd use the same thinking for the paint topcoat. Typically, the cost of 2-3
individual quarts equals the price of a full gallon. 2 evenly applied finish
coats should use about a quart apiece. Nobody says you can't give a third
coat . . . especially if the boat will 'live' on the trailer and be subject
to the abrasion of repeated launch & recovery cycles, as well as weathering.
I also like to have some 'extra' available for touch-ups and the like. Buy a
gallon and 2 or 3 empty quart cans. Do all your work / painting. Decant the
remainder into the empty cans. Fill COMPLETELY and label, including the
DATE, seal tightly and store up-side down.

Regards & Good Luck,
Ron Magen
Backyard Boatshop

SNIP

> Based on my use of epoxy before I'd think using the epoxy for a barrier coat
> would be pretty costly wouldn't it? We're talking the same epoxy that I use
> for repair, just without any filler, or mat right - liquid only? How much
> of that would you think would be required? Far less than for general
> repairs?
> SNIP

Reply to this Message

Chris - 29 Mar 2006 22:45 GMT

Thanks Ron, your information is superb.

As it was warm enough today I just took off the cover on the boat to inspect
how it made it through the winter, and I examined the hull. Given a few
spots where it obviously struck something, rocks, etc over the years, I can
see that it has got to be gelcoat, and definitely not a layer of paint.

I think I may go with doing the repairs with the epoxy, and then putting a
coat of epoxy over the whole darn thing to seal it up. You're right, as it
isn't porous, it shouldn't use too much. but is still far better than
something else for protection.

The paint I end up using will then have to serve the role of paint and
nothing more.

> Chris,
>
[quoted text clipped - 62 lines]
>> repairs?
>> SNIP

Reply to this Message

Boat Forum / Building / March 2006

bottom coat