Fiberglassing over wood

[topcar]

I did a comprehensive course in fibreglass and reinforced plastics at technical college here in Sydney. I am NOT proposing you use the thinned resin mix for laminating but use it to create a resin penetration into the wood. This gives a sound base for the following construction laminates to bond to. I have used this technique many times and have never had a delamination from the timber. Practice on a piece of plywood— brush in the penetration base thiinned resin then build up some layers of laminated glass. Hit it with a hammer to test the result. The lamination should not separate. You can get a breakdown of the plywood not a separation.

[coopec43]

Topcar


What about updating your profile!!

[rslifkin]

Topcar has a very good point. On plywood, you don't need an infinitely strong bond or anything. It just has to be stronger than the point where the plywood starts to fail.

[Chotu]

Originally Posted by rslifkin

Topcar has a very good point. On plywood, you don't need an infinitely strong bond or anything. It just has to be stronger than the point where the plywood starts to fail.

That’s the truth.

I made some plywood and epoxy and fiberglass outboard motor mounts. They were just temporary ones. I ended up using them for four years.

The failure point was that the Completely non-rotten, not wet, perfectly dry Layers of plywood pulled apart. I think I went above the engineering specs on that one. Ha ha

[BBill]

Originally Posted by coopec43

Sometimes I read an online opinion on (say) thinning resin with styrene (or acetone) and my immediate thought is "Does this guy know what he is talking about?"

I can't find it now but he doesn't approve of thinning with acetone either. He says to let the resin coating cure and then add the lay-up. "If it is not cured it will draw the resin out of the wood"

I just looked at the guys' background who advised against using more than 2% styrene to thin resin (See previous post) and I'll take his word as gospel

I wouldn't use that individual as a reference for anything. There is no way he has the experience in the frp trade he posts. Yrs back (on another web site) he said styrene wasn't a poly resin thinner. The problem with his statement is EVERY resin manufacturer on the planet says it IS a poly resin thinner...and cross links the poly chems together. Acetone cleans and doesn't crosslink. Regardless, 2% max thinning with styrene is what the majority of resin mfgs spec. None spec acetone for thinning. All this is very easy to confirm with the mfgs. Yrs later that guy changed his tune (on the web site you provided) and says styrene IS a poly thinner. There is other mis-information posted by him but I'll leave it alone.

[s/v Jedi]

I have been using Totalboat penetrating epoxy for a while now and thin it 40% with denatured alcohol. It works extremely well and a single coat does the job.

Edit: the picture shows a bad spot in cheap birch plywood. You can’t feel it anymore, the epoxy coating is glassy smooth. When you sand it, you get a surface that is rock hard wood fiber reinforced plastic, ready for laminating or painting. I used varnish over it which looked great as well.