JEM Watercraft

Can't remember where I read it, but someone talked about dilluting epoxy with acetone and "saturating" thier plywood before proceding with thier build. If you're out there and see this, please write back with the details of this step, and what benifit you have experienced by doing it.
On the by...... thanks to all who participate in this forum and @ Southern paddler, you folks are lifesvers to the uninitiated.
Lee

Some builders add a small amount of acetone to their epoxy mix to thin it in hopes it will penetrate into the wood deeper.

There's some debate about how effective it is. One issue that raises a flag for me personally is that acetone eats adhesives so you might be attacking the glue that holds the plies together.

You can get deeper penetration by warming the wood and epoxy, but warming the wood is not always practical.

I've done the thinning trick when repairing some rotting window sill wood. But I used denatured alcohol instead of acetone.

Matt,
What ratio of dillution do you use with the alchohol for thinning?

I have pre sealed wood before adding fiberglass. I'm not sure it is necessary, but it is said to reduce outgassing.

I've used acetone and alcohol to thin epoxy. Right now, I think alcohol is safer.

Ratios? I don't know. I'm a painter by trade and just mix by "feel" For a pint of mixed epoxy certainly not much more than one or two small cap fulls.

Always add to thoroughly mixed epoxy and resin.

On warming wood.

Robb White, a small boat builder from Georgia, always heated his garage to "tropical temperatures" and also placed heat lamps on the hull before adding "googe". He wanted the wood and epoxy to be hot. He often said he had to epoxify in his scivvies in order to stand the heat.

Robb passed over the bar a couple years ago. He built canoes, pirouges and high end small rowing and sailing craft of his own design. His boats sold for thousands of dollars and there was a waiting list of clients.

Robb was a prolific writer. His short essays often appeared in Messing About in Boats magazine. He definitely had a way with words and would always entertain with his southern turn of phrase.

Robb has left a website (and a few short stories) at:
http://www.robbwhite.com/

I can't remember exact amounts. But it wasn't much. If you mixed a full (baking) cup, you'd only add a couple tablespoons. It doesn't take much.

It's pretty easy to just add a little, mix, and then decide if it's thin enough.

I add just a small amount , very small amount , of the acetone to the epoxy , just to make it runny and watery , it really soaks in the wood. Never have measured it just a spoon or two full, might say I do it more by eye.

Chuck.

Guess it's true, y'all have taken up the mantle for the "Shell" answer-man!

Here's another take. I read in a tutorial, I believe it was West Systems, that it is not a good idea to thin the saturation coat. While ti will get a bit more penetration, it has a bad effect.

As thinner evaporates, it exits through the epoxy, leaving a matrix of tiny holes. Water seeps in through these holes. The epoxy manufacturer was not in favor of thinning.

Lee,
I use West Systems exclusively - in tropical heat.

West advise against using acetone (or, if I understand correctly, anything else) to thin the epoxy. That is good enough for me. Part of their reasoning is as Jack said.

I have found that the epoxy will only "saturate" or more properly penetrate the ply to the first glue line anyway. In most cases, the outer veneer is only about a millimetre thick and 'straight epoxy should have no problem penetrating that thickness.

The varied replies I'm seeing reminded me of an old joke.....


"Mama, Mama, I'm tired of going around in circles!"

"Shut up or I'll nail your other foot to the floor!"

Thanks for all the imput guys.

Lee