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Hello, Friends,
I have an x-braced back with induced arch in both axis. Earlier this spring, I ran out of time and ideal humidity to glue this back to the box. Predictably, it has "potato chipped". The effect isn't bad, but it has definitely straightened along the heel-to-tail axis. I have no plans to resume this project until late autumn or early winter when the humidity lowers in my shop. I'm curious as to what I should expect from this back. I know this has happened to many of you from time to time. Do braced plates tend to return to their original shape with lower humidity, or do they tend to remain "deformed"? It's not a huge problem nor an expensive one either way. The back plate is locally obtained black walnut and I have plenty of it. I'm just curious about my chances of resurrecting this particular plate sometime in early winter. What experiences have you had in this kind of situation? Thanks to all.
Patrick

I had a back do the same a long time ago and since then have never braced a back until I'm ready to attach it to the sides. In other words, I don't leave a back braced longer than overnight before attaching to the sides. On a top, if it moves a little, you have the advantage of string tension to pull it back up and take out a little flattening that might have happened. With the back, you don't have that benefit. If you are using a go-bar deck you can put the back on the hollow dish and press it down with go-bars when you glue it to the sides. This will help re-form the arch a little.

Thanks, Glen. Actually, I planned an immediate glue up as you suggested, but then got delayed a week and by then the humidity was quite a bit higher. But your idea about the radius dish is a good one. I'll try clamping the back in the radius dish. If it conforms to the dish, I'll just store it that way until I can glue it. If it doesn't conform, there's no reason I can't make another back next winter.
Patrick

It should return to normal when the humidity returns to the level it was at when you braced it.

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Thanks, Tony, I suspected that was the case. I'm not on a schedule and have plenty of other things to do over the summer months, so I'll just wait and we'll see how it goes.

Patrick

Ain't no thang!

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