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I have a mahogany body blank that is one piece 30 1/8 x 13 1/2 x 1 11/16 looks to be flat saw.

I've had it for a while now and it was given to me about 6 months ago I believe, it has been sitting in my shop ever since I cleaned out the space. I have no humidity control and I do not have a hygrometer as of right now.

My question is when I got the stock I checked it with a straights edge and it was very straight maybe .01 - .02 of a gap in the middle on the top, so the top was concave and the back was convex. At that point I figured I could just cut my body out and sand it smooth. its been very humid around here for a while I wish I could give you a RH % but I can't. Now looking at the top with a straight edge again one side is straight no gaps and the other side has a gap no more than .05.

The plan for this board is a semi hollow electric and I'm curious if I can sand both faces parallel to each other watch the board for a while and go from there. I will be using a walnut carved top on this. I think I should wait for the humidity to drop for a while see if it moves and glue up around the same RH as they do with acoustics.

I Appreciate your thoughts, Mike

I wouldnt worry about it. As long as your not doing a strat style hardtail where the bridge needs to be completely flat on the face of the guitar, I think you'll be fine. Hopefully somebody with a little more excperience than me chimes in. -Alex

It's a good thing, not a bad thing. The body blank has just adjusted to the ambient humidity. Since you refer to it as a "body blank," I'm assuming you had it shipped from somewhere? Having left it lying around for six months has given it the opportunity to do what it's gonna do, and it's better that it warp now than after you built with it. The best thing to do is get it flat again.

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David Morris

I suggest you ship it to me for disposal....

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"Act your age, not your shoe size" - Prince

Ill need an address... But if I sand it down in really high humidity once it drops back down or below avg wont it move back to its old shape so if I sand it flat it would just end up bowing the other direction right? or will the glue joint between body and top hold it in place?

No. We're not dealing with a thin acoustic plate. This wood is thick enough. If it's sitting aroung for 6 months, it's pretty much equalized as far as the internal moisture present in the wood. And it would take an awful long time(probably months) of high humidity for it to take on enough moisture to cause problems. and once you get a finish on it.... I'd flatten it and build. MHO.
Of course, this is assuming that by body blank, you mean a kiln dried blank bought from a reputable supplier. If not, I think the rule is 1 year per inch of thickness. Which, according to your measurements is near 2 years.

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Mike

The only thing nescessary for evil to thrive is for good men to do nothing.