I haven't tried it. Were I considering such a trick I'd write MAS and see what they think.

When I was doing electron microscopy decades ago we had a protocol of imersing samples in alcohol, acetone and other stuff that took about a week to embed them in epoxy. I'm not sure that's what you're looking for.

Your trailer beds are going to be covered in carpet or something else soft, no? If so, why do you need deep penetration of the wood? It won't be abused by the boat.

   About 5 years ago I built a stripper SUP and coated the inside with epoxy thinned with denatured alcohol to seal the wood. I don't recall the exact ratio but it was fairly watery.

Dan

After smoothing fillets of thickened MAS epoxy with denatured alcohol (ethanol-based) on my current build I've noted deposits left behind where the excess alcohol run-off had pooled, then evaporated. These deposits aren't sticky either once the fillets have cured, and won't come off after wiping with alcohol-dampened cloths.

Others here indicate thinning MAS products may cause an epoxy batch to cure with porosity, resulting from minute voids in the cured epoxy matrix being left as the solvent evaporates.

Years ago I used an epoxy from Clark Craft that had a solvent available under the same lable (Marine Epoxy I think it was; stuff cured slightly flexible too, not stiff/rigid as does MAS LV). Strong odor from this this product though kept me from continuing use.

I just put this question to the good folks at MAS, will report back here what their reply may be.

Copied directly from the e-mail reply I received from MAS tech support this afternoon:

"Denatured alcohol works well for thinning LV resin. You can also use xylene which works very well and I know a few users who actually spray LV by thinning it down 15%. Acetone also works but I understand your concern with it’s flammable nature. Make sure you don’t add more than 15% to the total mix ratio of epoxy which could potentially weaken the structural bond of the epoxy.

Let me know if you have any other questions.

Thanks

Derek Shurson |  Sales & Marketing

ENDURANCE TECHNOLOGIES

Direct:  651-554-4059  |  Toll Free:  800-755-8568  |  Fax:  651-451-9728"

I verified by phone call that it's 15% by volume for whatever thinner you choose to use, and that this is a maximum amount. Preferable to use as little as possible of course, and that 5% is often enough for what we do.

And that I could quote Mr. Shurson verbatim from his reply.

   I don't want to rain on your project, but I'm at 16 years on PT pine trailer bunks and they are in great shape. Carpet is on #2 installation. 

I had success thining MAS with acetone. It penetrated well and cured perfectly. It has to be done in a well ventilated area with absolutely no sources of flame or spark (like power tools). Works well, but you can asphyiate or blow yourself up if you aren't careful.   

Why do you feel the need to penetrate the plywood?   An epoxy coating is tough and waterproof and will seal the plywood without thinning. It works perfect on stitch and glue plywood boats so why not on your trailer bunks?.

I had the same thought, but it's been awhile since I'd read a forum thread about it so felt it worth the asking.

Certainly with interior softwood ply it might help some if thinned epoxy gets past the glue layer into interior veneers. With exterior softwood ply I doubt that'd happen to any significant degree.

With marine-rated ply? Probably not worth the effort.