Advice on fixing a crack on the top of my wife's '60s Kamaka?

Hello all.

I'm fixing my wife's old all-wood (not laminate) Kamaka soprano. The bridge came unglued, and I figure before I glue it back on, I want to fix a with-the-grain crack it has alongside the bridge. I'm guessing it got whacked on the bridge a long time ago, and low humidity made it worse. The crack is about 2" long. A friend who's worked on guitars (but has never seen this uke with his own eyes) suggested gluing a cleat or two across the backside of the crack, and maybe filling the crack with glue, if there's a gap.

I'm going to do it "right" and glue the bridge on with hide glue (Old Brown Glue, specifically), since it looks like it was originally glued on with hide glue.

Should I use hide glue to glue the cleat(s)? Or wood glue (since the cleats would be permanent, anyway)? Not sure about the filling-in-the-crack part.

I haven't measured, but I think this uke needs some humidifying (I'll probably get an Oasis ukulele humidifier). Should I get it back up to where it should be before I fix it? Does it matter?

Any other thoughts or advice?

Thanks!

pictures:
http://www.flickr.com/photos/mcgreivey/4405800447
http://www.flickr.com/photos/mcgreivey/4405800417

If you are going to use hide glue to reattach the bridge, you may as well use hide glue and percuss the glue into the crack. That simply involves spreading a line of glue above the crack and tapping rapidly with your finger above the crack, forcing the glue into it. Do that for thirty seconds or so and wipe off the excess glue with a damp cloth. Hide glue is great for this kind of repair because it will draw the edges of the crack together as it dries, no clamping is necessary. I would keep the uke fairly dry before the repair to make getting the glue into the crack easier and humidify immediately after the repair. That will also bring things together. If the glue gets into the crack OK, you probably do not need to cleat it.

Brad

I've read articles recently about crack repair. There is also a series of videos on YouTube by Bob Taylor of Taylor Guitars demonstrating how they rehumidify dried out guitars to close up cracks before gluing.

Stewart MacDonald now sells a perforated "glue knife" to help get glue down into the crack where it needs to be.

http://www.youtube.com/user/TaylorQualityGuitars#p/u/76/GS6GqjP-zMY

http://www.youtube.com/user/TaylorQualityGuitars#p/u/78/tB8tELj43RE

http://www.youtube.com/user/TaylorQualityGuitars#p/u/77/bWcGdWFiv4M

I agree with Dave humidify it first to see how far the crack will close before glueing it. My friend that has been a luthier for 20 uses this method. He also uses thin CA super glue to penetrate the crack and wood. You will have a hard time getting hide glue into a crack it is like honey when liquid.

Please let us know how it turns out....

I too, would use ca glue. The thin stuff first, so that it wicks into the crack, followed by medium to fill the crack. Super glues are very unforgiving so unless you are very familiar with how they work you may want to use a different method. Be prepared to refinish the area.

Thanks all.

I can see how a thin glue superglue would be nice to use, in a way--but I don't want to take a chance on having to refinish.

The crack may be just big enough to get hide glue in there with a thin blade. But first, I doing some "reconnaissance". I'm trying to get in there through the sound hole with a little flash light and a dental mirror to see what's going on. There are two ribs in that area: one running diagonally across the center seam between the two halves of the top, and another roughly parallel to it that seems to run across part of the crack. I want to see where the crack is in relation to that rib, because the crack is displaced a bit. Looking from the outside, the bridge side of the crack is lower by a mm or two, so a cleat or two might be a good idea, to get rid of that displacement.

It would be an easy fix if I could take the top off, but that would be a whole new kettle of worms.

(I'm calling them ribs, because I've worked on wooden boats, and I'm too tired to go look up the correct term)
(OK, looked it up -- brace?)

It is always difficult to offer specifiic advice without seeing the instrument. One trick for realigning the displaced sides and gluing cleats over the area is to use rare earth magnets. These powerful little suckers can do wonders in realigning things and applying clamping pressure to hard to reach areas. Stew-Mac sells them, but you can find them at a number of places.

Brad

^^ Magnets: great idea! Thanks.

I'm going to re-humidify it, then proceed from there.