Checks and splits in marine plywood...

[Ken]

I am "polling" for ideas...
Paul, Jay and I are renovating an old fir plywood covered Pelican sailboat. We stripped the sides due to lots of splits and checking in the paint(the bottom looked great with its layer of fiberglass). We filled a few low spots with Evercoat Light, sanded it smooth and primed with Prekote 1-part primer.
It looked great...until the paint dried and shrank, reexposing most of the old checks in the paint. "Master" Marty suggests filling those voids with Evercoat Light, sanding and priming again. I'm worried they will reappear...
Has anyone had similiar experiences that were successfully remedied over the long term? Far be it for me to doubt the guru: I am just trolling for additional experiences. Any thoughts out there? Thanks! -Ken

[Tim_Mattson]

Epoxy

Hey Ken,
This might be time for Epoxy to save the day.
It pretty much will not fail unless what you`re fixing is more dirt than wood.
Some thickener or gap filler will fill larger cracks.
TimM

[BrianVic]

fir plywood checking

I agree with Tim

I have built several dingy sailboats with Douglas Fir; El Toro, OK Dingy, and couldn't stop checking with paint only. Back then I remedied by using poly resin and cloth, but these days epoxy is better for this application. If you are concerned about weight, use peel ply over the layup. I have made a number of aircraft fairings and cowl modifications, and have become addicted to it. Google "peel ply." It is Dacron - really cuts down on thickness (saves money by reducing epoxy quantity), makes it much smoother, reduces the need for additional coats of epoxy to fill the weave, almost no sanding to get a smooth, faired surface. Not that expensive - I purchase it from Wicks Aircraft Supply. The finished layup will look like it came from Boeing.

I have been purchasing epoxy from www.aeromarineproducts.com. Way less expensive than West and System Three. As I recall, the three gallon kits are $140, including pumps. Shipping is from San Diego, so not that expensive.

Poly cures much faster then epoxy, but I consider this a positive because I’m a slow worker when doing layups. In a 60 to 65 degree shop environment, you have a good hour or two before it starts to noticeably thicken, and even then it is very gradual.

Brian Vickers

[BrianVic]

Estimating materials

PS - This website has a useful list of fabric vs. resin quantities. Very helpful in "ball parking" resin quantity needed for a given weight of fabric; mat, woven, biax, combos.

http://www.fiberglasssite.com/servle...and-How/Detail

Brian Vickers

[Ken]

Seek and you shall find!

Good ideas, gentleman! I will sleep better tonight! -Ken