As HPD is just about to tackle glassing the inside of his Merlin, it occurred to me that as I glassed mine I got a lot of air bubbles. I had to go back over the wet glass a number of times to get them all out and still ended up with some that came up when I was no longer willing to touch the glass. I ended up sanding these out as best I could. Any suggestions on how to prevent them?

JD

when glassing my paddles, i usually will apply a super thin layer of epoxy and let that cure fully before doing the glassing. A lot of the air bubbles seem to be air escaping from the wood, and this step eliminates the air coming from the wood.

So, thin layer of epoxy, light sanding, then glass...

It does wonders on the paddles anyway.

The problem you describe is out-gassing. What happened is your work room warmed up as you were glassing your canoe. The trapped air in the wood was expanding as the room, and your canoe was warming up.

This problem can be almost completely eliminated by warming up the room, before you glass and allowing the temp to remain steady or drop very slowly as you glass the canoe and allow the first two layers of epoxy to cure. The problem is almost non-existent by the third coat.

Some air bubbles will always form as the epoxy displaces the air trapped between the strips and in the wood fibers. They can be brushed out or touched with your finger as they form. As the layers of epoxy set-up, the bubbles will cease to form.

since you have already experienced the air bubbles and the small craters they form after the epoxy has cured, you will need to fill them with a small drop of epoxy and allowed to cure, then sanded smooth if you want them to become completely invisible. They cannot generally be sanded out.

tom