Thread: bottom coat
View Single Post
  #3   Report Post  
posted to rec.boats.building
Chris
 
Posts: n/a
Default bottom coat

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.





"Ron Magen" wrote in message
news:SWaWf.15974$W75.13159@trnddc07...
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

"Chris" wrote in message
...
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