Top wood causing whole body to warp?

[Dan Hehnke]

So I noticed that my top piece of joined koa that I am using for the top of this latest guitar was warping a bit while sitting on the bench before gluing to my semi-hollowed out piece of Alder. Depending on which side was facing up it would warp the other way by the next day. The weather has been changing alot here (near Denver, CO), so I figured that was normal. But now that I've had it glued to the alder body for a while, the whole thing has warped noticeably down. (sides bent down as seen from side view from the bottom). I've never seen such a thick assembly of wood warp this much. It's kind of cool how it is, but the unpredictability is kind of irritating me. Has anyone experienced this kind of thing, and can you do anything about it? Both sources of wood were good ones, and stated that the wood was dry (I think koa was kiln dried, and body was air dried). Thanks for any input.

[Henrique Schneiter]

The body and top woods probably warped for the same reason (weather changing), I don't see the top forcing the core to warp, BUT, if you used a waterbased glue, it can be caused by the glue. In my limited experience in such cases, the warping is transient (until the glue dries out completely), you may just want to clamp the whole thing to a flat table for a few days.

[Dan Hehnke]

Thanks Henrique. Yeah I did use standard titebond wood glue. I am actually fine with the shape the guitar has taken now, I just hope it doesn't move around any more. And I wish I could do this on purpose to make a cool domed top again