[Rhodes22-list] Surface Coating for Floor Boards for an Inflatable Dingy

[Roger Pihlaja]

Bryan,

I would use epoxy to stabilize the plywood laminate against water intrusion.
The best way to do this would require a high pressure autoclave to force the
epoxy deep into the laminate.  Since you probably don't have access to such
a system, here's what I would do:

1. Sand off all any remaining varnish or paint on the plywood floor sections
& set them up as if you were going to varnish.

2. At room temperature, use WEST SYSTEM 105 epoxy resin, 209 extra slow
hardener, and cut the mixture to about 50%wt with acetone.  Mix the 105
epoxy resin with the acetone and get it blended up thoroughly.  Then, blend
in the 209 extra slow hardener.  You should end up with a mixture that is
very thin (low viscosity); but, still brushable.  WARNING: Acetone is very
flammable & the vapors are somewhat toxic.  So, be careful about ignition
sources and provide plenty of ventilation.  Wear personal protective gear
(PPG) such as rubber gloves, rubber apron, rubber boots, goggles, chemical
vapor respirator.

3. At room temperature, this thinned epoxy will have a pot life of about an
hour.  During this time, keep brushing the liquid onto your floor sections,
paying particular attention to the places where the plywood end grain is
exposed.  The thin epoxy should soak into the wood about as fast as you can
brush it on.  The acetone solvent will evaporate, leaving behind the epoxy,
which will cure up deep inside the plywood laminate.  If there is any
interior rot in the plywood, the epoxy will arrest the rot and should
permanently stabilize the laminate structure.

4. Leave the floor boards hanging at room temperature for at least 8 hours;
but, not more than 20 hours to allow the acetone time to evaporate & diffuse
out of the wood plus have the epoxy cure to a green state.

5. At room temperature, mix up another batch of WEST SYSTEM 105 epoxy resin
& 206 slow hardener.  Brush this mixture onto the plywood surface like it
was varnish.  Some of it may soak into the wood; but, most of it should
layer on the surface like varnish.

6. Leave the floor boards hanging at room temperature for at least 2 hours;
but, not more than 12 hours to allow the epoxy time to cure to a green
state.

7. At room temperature, mix up another batch of WEST SYSTEM 105 epoxy resin
& 206 slow hardener.  Add WEST SYSTEM 422 barrier coat additive until the
mixture has a viscosity similar to exterior latex paint.  Brush on two or
three thin layers of this material allowing 2 to 12 hours between coats.
Let the final coat cure for at least 24 hours

8. Wash away any waxy amine blush on the surface with acetone.

9. Do any required finish sanding at this point.

10. I would finish up with a good polyurethane topsides paint like Awlgrip
or Interthane Plus Two-Part Polyurethane in the color of your choice.
Consider sprinkling some coarse washed sand over the wet paint to provide a
nonskid surface.  NOTE: Even with the 422 barrier coat additive, epoxy does
not have good resistance to UV.  Therefore, this final coating of paint is
essential for long epoxy life.  This will be especially important in an
application like a floorboard where it may sit for long periods with water
on it and the hot noon day sun beating down.

All this probably sounds like a royal PITA; but, it should provide you with
a set of bulletproof, maintenance-free floorboards.

Good luck!

Roger Pihlaja
S/V Dynamic Equilibrium

----- Original Message -----
From: "Bryan Childs" <bchilds1 at peoplepc.com>
To: <rhodes22-list at rhodes22.org>
Sent: Wednesday, December 22, 2004 3:54 PM
Subject: [Rhodes22-list] Surface Coating for Floor Boards for an
InflatableDingy


> I use an inflatable dingy for my Rhodes when cruising and I am in the
process of rebuilding the floor boards.  (Heading to the Florida Keys in
late Jan) These are boards that are linked together that form the flooring
of the dingy.
>
> The original boards were varnished and did not last very long so I am
searching for a more durable coating.  Remember the edges of these boards
are submersed in water particularly the stern section.  I have marine
plywood but need opinions on the best coating: varnish,  epoxy paint, resin.
>
> I know Roger will have some good ideas.
>
> ________________________________________
> PeoplePC Online
> A better way to Internet
> http://www.peoplepc.com
> __________________________________________________
> Use Rhodes22-list at rhodes22.org, Help? www.rhodes22.org/list
>
>