Warpy Balsa Woes

I bought some 1/4" medium grained balsa sheets last week. The plan is to laminate two with epoxy to make a new 1/2" profile fuselage for the Yak-9 and also another one to make my speed plane. One was slightly bowed, so I chose it to laminate to another since the glue should fix it straight and stiff.

Monday evening I cleaned off my 3/8" glass worktop and collected my clamps. I cleaned both sheets with a paper towel and acetone and placed the first one on a strip of wax paper. Then I filled a mixing cup with an ounce of two part Loctite 60 minute epoxy, and squeegeed it evenly and very thin. I placed the other sheet on top, pinned it and applied 6 clamps, starting in the middle, across the 36" span of wood. I used the minimum pressure to hold it perfectly flat against the glass. A little glue oozed out of the edges, so I wiped it off and left it to harden. Later that night the remainder of glue in the cup was hard as a rock. It had cured nicely.

This afternoon, I took the clamps off and the damn board sprung free with a helluva bow. Not what I had expected. I soaked it with Windex and placed it back on the glass with a flat carpenter's pencil under each end and set a couple of weights on it to counter-bow it. I'll check it tomorrow to make sure I haven't bowed it back too much, and decide what to do. The humidity is high, so it may still be wet in the morning.

Meanwhile, I opened my new Skyray kit and of course the fuse is not only bowed to the inboard side, but twisted on the front end. It too dried under weights flat against the glass for 48 hours. Its bow is gone, but the twist is not, so I wet it again and weighted it down. I'll check it after another day or two.

Any tips on straightening and laminating would be welcome.

Rusty