Violin Forum/Message Board

[Becky]

My husband is a music teacher and brought home some classroom guitars with cracks in the top plate. He was wondering if I'd be able to do anything about it. I've repaired violins with cracks, but know close to nothing when it comes to guitars. Before risking ruining any instruments I wanted to see if anyone here knows the similarities and differences between repairing bowed stringed instruments and guitars. Is the method for repairing cracks on a guitar similar to repairing cracks on a cello?
Thanks!

[Alaina Toadpipe]

Hello, we regularly repair cracks in guitar tops in our shop, and it, as far as I know about violin repair is similar. Usually, using a scalpel we create a cleaner "cut" that is easier to fill. Then using the same material as the top, we create a fill piece that will be set in and glued after the splints have been put in. The splints are just like the ones used when working on a violin. ~2mm high max, and about 6-8mm square, though that varies. We make a tiny hole in the splint, and using a ball end string we can us the ball as a sort of clamp as it dries. We've rigged a sort of jig out of machine heads to tension the string and it sits directly on the top of the instrument. The bottom is corked so it doesn't mar the top. Once the splints are dry, off goes the jig and out come the strings. Then in goes the fill piece with a bit of glue. After the glue there is set, plane down to the level of the top, and apply a bit of finish. I hope this helps, I have the feeling this will be an easy job for you, if you've already done repairs on arched instruments. Good luck!
PS sad to say too, but if these are really cheap guitars (no binding plywood top/back/sides) it might be just as easy to inject a bit of epoxy instead, since trying to fix a plywood top is a lot more hassle than a solid.

[Jack H.]

from what I have done n the past there are 2 methods, one is to use a shellac stick and fill it in with the proper color and the second is to fill in the crack with new wood cut perfectly to fit. I guess you can also use a plastic wood filler, but I do not think it would be strong enough.

[FiddleDoug]

My guitar repair experience is limited, but I did pick up a decent book so that I could take care of minor stuff n my son's guitars. "Guitar Player Repair Guide" by Dan Elwine (about $23). Cracks do get repaired about the same way, but for hairline cracks, cyanoacrylate glues are sometimes used. Final finish is often a spray lacquer rather than varnish.
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Doug Wall

www.wallindependent.com

[Geemac]

You may find some help by snooping around http://www.stewmac.com as there is quite a bit of free information there.
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GeeMac