Warped Ukulele Body

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Warped Ukulele Body

Postby Rich Friedeman » Tue Oct 04, 2016 5:56 pm

I just closed the box on my first acoustic build -- tenor ukulele with wenge back and sides, mahogany top. It had been going pretty well, but I now can see a critical issue. The body is very warped when I sight along the soundboard.

I doubt I can recover from this -- it's all titebond 1, so no joint is easily reversible -- though if anyone has ideas I'd love to give it a shot.

My question is more about how did I get here. I bent the sides on a form with a blanket, then clamped them into a mold after they were cool. I carved an arch into the back of the sides (so the body's thinner at the heel), added the blocks, kerfed, then kept it in the mold while I sanded a dish into the front and back. At that point, everything was even and matched up well. I braced the back and attached it, then removed it from the mold so I could cut in a soundport. I didn't return it to the mold to attach the top, because I couldn't get any spreaders in there anyway, with the top going on. I also didn't think to check for a twist before gluing on the top, but my braced back didn't seem out of order.


I'm going to finish the instrument, even if it's destined to be firewood, so I can make more first-time mistakes here.

Any thoughts about where I might have gone wrong or what I can do to either put it right or avoid it next time?

Rich Friedeman
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Re: Warped Ukulele Body

Postby Bob Gramann » Tue Oct 04, 2016 6:17 pm

Careful heating (like with an iron) will soften Titebond Original so the joint can be separated with a blade. Heating a spruce top is likely to stain it. But, you may not need to do that. Sanding the fingerboard flat after the neck and fingerboard are attached, and setting the saddle so that the string height above the fingerboard is right might be all that you need.

The top probably ought to have been attached while the instrument was in the mold and the top supported by the dish. You ought to be able to design a spreader that you can get out through the soundhole (or at least through that port).
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Bob Gramann
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Re: Warped Ukulele Body

Postby Chris Reed » Tue Oct 04, 2016 6:21 pm

Two suggestions:

1. For the future, don't cut the sound port before the top is on. Lock in the geometry, then do the extra stuff.

2. For this uke, carry on assuming the top is correct - ignore the directions in which back and sides go. That way your final instrument will be playable.
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Re: Warped Ukulele Body

Postby Rich Friedeman » Wed Oct 05, 2016 12:34 am

Thanks Chris and Bob. It sounds like good advice and I definitely feel better prepared for the next one. I am going to finish this build, since I have nothing to lose. It sounds like I may be able to get a playable instrument out of it, even if it's not a showpiece.

Rich Friedeman
Posts: 19
Joined: Fri Mar 02, 2012 12:06 am

Re: Warped Ukulele Body

Postby Clay Schaeffer » Sun Oct 09, 2016 10:36 am

Since it is a uke, you could carefully saw the top off the sides with a hand saw, clean up the glue residue on the top using vinegar to soften the titebond (then rinse with water before regluing), sand the sides on a flat sanding board to remove saw marks and true them up, add a couple of small ladder braces to the top that will touch the sides and hold them in the proper position, place the top on a flat board and reglue the sides to it clamping them flat to the top. When regluing make sure you put glue on the ends of the braces to glue them to the sides and avoid any annoying buzzes. You will lose a little bit of depth to the box, but not enough to worry about.
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