need your thoughts..

I've just bought a second-hand Martin S-O with a back that has detached from the sides for 5 inches or so.

The problem is that the side needs to be pushed inward to align with the edge of the back along half of the detachment. On the other half, however, the side needs to be pulled outward to align with the back.

There are no linings on this model uke.

I have tried wrapping doubled twine around the uke along the side and twisting it to pull the side in and that works along the part where it needs to come in...but it does not result in springing the other part outwards where needed.

How would you repair this? What adhesives would you use?

I was thinking of using an instant glue to reattach most of the part that needs to move in, as I can hold it in place while the glue sets...and then putting some sort of temporary brace inside to flex the side out where needed, and then glue that with red cap titebond.

Having trouble posting pics from my tablet but there are pics on a thread I posted here in the Uke Talk section

I would use a heated block and hot knife to remove the back completely. Then inspect and repair any other faulty interior glue joints and install a 1/16” thick solid lining. Then, build a work board using 2” long pieces of a 1” dowel around the perimeter. The dowels are drilled 1/16” off center and are used as cams to control the outside shape. Thin, flexible lengths of wood are used in the interior to press the sides against the dowels as necessary. Then glue the back on with red cap Titebond.

I agree with Brad. The back usually needs to come off. When you start taking the back off these old ones they almost fall apart usually . A lot of guitar guys make a quick form the shape of the guitar before they take the back off to hold the shape. I don't see why you couldn't use the top to make a quick form of 3/4 mdf slice it in half then clamp it around the uke.. You will need a band saw to do this effectively. If I take a bck off I figure I will need to resand flush the sides. I use hide glue in a squeeze bottle and go around all the joints while inside.

Thanks for the input!

I hope not to have too many problems removing the back. It's not a particularly old uke... probably less than 10 years, and the back has no cracks.

Another feature of this uke, as designed, is that the braces on the back do not extend fully across the back, they stop short of the sides by something like .5" on either side at the lower bout, and .25" at the waist.

Assuming I installed lining, would you also replace these short braces with new braces that extend all the way across the back?

I wouldnt take it apart. I would make a patch to fill the open space. I think you will have more problems if you take it apart .

Take what I'm saying with a grain of salt because I'm new to this... but if you’re not feeling comfortable with the idea of pulling it apart, I'd probably file or cut one or two tiny divots into the side on the section that's pulled into the body. Then I'd take a couple paper clips and shape/bend them so that they hook through those divots and behind the side, pulling it flush to the edge of the back (and holding it there). Then I'd place some strips of masking tape to hold down the back tight and wick crazy glue to into the seam (check YT videos of people doing tape/CA to glue down binding). Remove the tape and wick it into the remaining gaps. Then snip the paper clips off a bit long and push them inside and shake them out. On the part that's sitting proud on the side, you wouldn’t need the paper clips but just tape it all down and wick in the glue.

Somebody with more experience - please feel free to raise a warning flag.

Paul Bouchard said:

Somebody with more experience - please feel free to raise a warning flag.

Click to expand...

Red flags! Red flags! Probably not gonna work too well... If you feel up to it, do as others recommend: remove the back, make a simple form from the back outline, put uke in form, spread sides with dowels or whatever, put in linings (solid or kerfed), glue back to ukulele with Titebond.

These Mexican Martin S0 ukes are relativley a new cost effective instrument design based on the vintage Martins and they dont have any linings, if they did ! this wouln't have happened.. So I would be tempted to fit some linings while the back is off to make it a stronger job.