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otterly2k
Nov-21-2013, 3:04pm
I am working on repairing an old A oval mandolin with a slightly canted top. I'm dealing with a cracked top as well as some cracked braces underneath... and I'm having trouble finding clamping solutions to get at those interior braces.

There are two transverse braces... one close to the sound hole which I was able to get at. It's the one that's farther back that is troubling me.

All my guitar clamps are too big, the nifty scissor jack thing that has worked so well in guitars is too chunky to even fit inside this mando. The braces are at about 3" from the soundhole... so the c-clamps I have are not deep enough, but the cam clamps I have are too deep and won't fit. The deep bridge clamps I have are too long.

Suggestions? Thanks in advance for any help...
KE

Dale Ludewig
Nov-21-2013, 4:07pm
Karen, I don't have the jpeg here, but some time ago, John H. posted a picture of some little clamps he'd made using guitar tuning machines. Perhaps he'll chime in. You'd have to drill a tiny hole through the top to get a string through, but then you could perhaps pass a guitar string through a block of wood (that would act as a caul) and then pass the wire through the top and use the guitar tuning machine to tighten things up. (I assume you're trying to glue a loose brace back up to the bottom of the top plate.)

sunburst
Nov-21-2013, 5:51pm
Those little string "gismos" are from the Don Teeter repair book. Really handy for cracks in guitar sides and some other things, but I wouldn't use them for the top of the mandolin in question (at least, without looking at it I'm pretty sure I wouldn't use them).
Assuming decent alignment of the top cracks and what you need is to lift the transverse brace into position and hold it there for glue curing, I'd probably make some little props, like sound posts, more or less, to prop between the brace and the back of the mandolin to lift the brace into position. For clamping, I would then use cam clamps and clamp the outside of the mandolin right over the ends of the props. That should do it. You can use a sound post setter, a pair of hemostats, any tool that will do the job to put the props in position.
It's a handy way to align top or back cracks too. Put a prop under the low side of the crack and clamp the high side. The clamp can then be used to "dial in" the alignment of the crack, then clamp the sides of the instrument to close the crack and glue it.

Doug Edwards
Nov-23-2013, 10:45am
I'm thankful for guys like John Hamlet, who are willing to provide his solutions and advice on so many different subjects.

fishtownmike
Nov-24-2013, 6:17pm
Here is a couple of youtube videos that shows these clamps in use. I originally got the idea from the Teeter book and made some out of wood. This guy used some type of plastic.
http://www.youtube.com/watch?v=0gjhTYHRtMg

http://www.youtube.com/watch?v=RcAPZ3oxi3Q