Creative Clamping

I bought this blue Stagg guitar a while back, my children (now all adults) learned to play on this guitar, it has given excellent service for the £70 I payed. It had a hard life, but finally succumbed to having a set of heavy electric guitar strings applied. This broke the glue bonding the bridge to the body, pulling the bridge away more than a third of the way across. This messed up the tuning and intonation, raised the bridge, bent the neck forward, so messed up the action, to a point where it has become unplayable.

The guitar seemed to good to throw out, but I had no idea how to fix it and it wasn’t worth paying for it to be fixed, as it cost so little originally, and was never a high quality instrument. Having watched Jerry Rosa on his Rosa String Works channel bring similarly damaged guitars back to life, I thought I would try repairing the blue guitar using some of the techniques he applies.

First of all I removed the strings, relieving the tension. Once this was done I checked the neck with a straight edge. As best I can tell it appears to be straight. Using the edge of a woodworking square I checked for raised frets. There appears to be only one fret standing proud, so that may require some attention, but it looks like I can probably sort that out. But first the damage at the bridge end needed to be sorted, which has been this afternoon’s project.

excess finish and top ply carved and cleaned ready for reassembly

I had to lever the saddle out from the bridge using a sharp chisel as it was a very snug fit. The saddle is a plastic moulding, so in keeping with the price payed. Then the piezo pickup below the bridge had to be pushed back into the body so that it could not be damaged. After that I applied heat to the bridge with a hot clothes iron until the remaining glue had softened enough to use a thin flexible knife to separate the bridge from the body.

block shaped for underside of the bridge, masking tape rolls to hold it in place while clamping

Once the bridge was removed it could be seen that it was possible the bond failed due to it only being glued down in the middle. The finish on the front was under the edges of the saddle so it was never fully glued down. The front of the guitar turned out to be plywood, where the original glue had worked, the bonding of the top ply had failed before the glue. To get a good flat surface for a new bond I had to remove the excess finish and the remaining shreds of top ply. This will drop the bridge by about 1 mm, however since the action was high this might still be acceptable.

Unconventional, creative clamping with automotive repair equipment, and glazing wedges.

To re-glue the bridge I needed to clamp it down whilst the glue set. It needed a deep clamp to reach in through the sound hole and hold the it fast whilst the glue dries. None of my kit was suitable, but a good friend loaned me a valve spring compressor with a deep enough reach. To use this unconventional luthier’s tool I had to make an odd shaped block to fit under the bridge inside the body and cut a piece of CLS to pack out the top. I then used a couple of glaziers wedges (I knew I’d find a use for them one day) to hold down the ends of the saddle. This was all set up dry, then once it was proven I coated both the body and the bridge with strong wood adhesive and reassembled the clamp. On the final clamp up there was some excess that needed wiping up, after that it is a case of waiting until tomorrow to see if it has bonded successfully.

Tomorrow I will need to see if I can contrive some sort of levelling bar to deal with that raised fret. Friday new strings are due to arrive, so it may be possible to get a working instrument by the weekend.

P.S. Edited to get the terms saddle and bridge the right way around.

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