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I glued up four sitka braces on my new EIR back. Each brace was carefully radiused to 15 feet and I used a 15 foot dish in my go bar deck. I left the braces mostly rough shaped and set the piece aside. About a month later after I returned home from the GAL convention I noticed that the back had lost the radius and was pancake flat. All braces were solid and glued firm. My shop has controlled humidity at 45%. What happened and is it salvageable ??

I've seen this before when I left a braced back flat on a bench for a few days. I put it down to moisture differential between the top and the bottom of the back. Turn the back over and leave it for a few days.....it might go back to being a nice "bowl" shape again. If not, you're probably going to have to remove the braces and start over.

Cheers,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

You could try laying it out in the sun on a bright day, braces up. Wood has a tendency to curl towards the sun. An old Mentor of mine used to do a demonstration with a 3/4 board. He would pick a nice straight one and lay it out in the sun in the morning and it would cup and warp toward the sun, lunch he would flip it over and buy the end of the day it was back to straight. Or nearly so. The point he was making was not how to warp a board or straighten it, but demonstrating the power the sun had over wood and how it caused it to change. Something we needed to be mindful of in building entry doors and exterior millwork. Any way could be worth a shot before carving off the braces.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Read William Cumpiano's Newsletter #22 for the why and what to do next.

http://www.cumpiano.com/Home/Newsletter ... ntytwo.htm