Here's an example of a small fix to get that guitar in working order once again. This may have looked like a lost cause to some but it's definitely not the case. This parlor size Simon & Patrick came in from a school, took a hit at the butt end and the top separated- No damage to the binding or bracing! The school just needed it back in working order, so we applied a little glue & clamps and it's doing good again.
This guitar had an existing preamp from factory but we're doing an upgrade. Thankfully the new preamp is a relatively close footprint from the last. We just need to dremel out the space to accommodate the new preamp- relatively quick job. In a case like this, I would just tape off the footprint and free-hand the cut.
The bridge on this Seagull was literally falling right off. It appeared that someone had attempted to repair it but to no success (remnants of glue around the parameter of the bridge).
To be safe I used some heat to pry off the last of the bridge. It required a thorough cleaning and resurface before reinstalling. The guitar also required humidity treatment to settle the top (warped from being too dry).
I use a super sharp chisel to clean off the glue and prep the gluing surfaces. Once the glue is removed, I score both surfaces for better glue adhesion. Then I glue and clamp the bridge for a few days before stringing it up and getting it back to the customer.
This old Regal's bridge had been pullup up off the soundboard for years. Because of this, the bridge itself has actually warped and will need to be treated before it can be reinstalled. The guitar also has numerous cracks needing repair.
These guitars weren't top quality to start with so removing the bridge shouldn't be a problem. You can see in the pictures that there are two screws that need to be removed first. Once removed it pried right off. No heat needed (never force off a bridge- always use heat as required).
To treat the bridge, I soak it and press it back into shape. This will insure it seats on the guitar properly. Before gluing, score the underside of the bridge and guitar to to give the glue a better hold.
You can see, even from this view- that bridge is lifting off the corner. This particular bridge is lifting due to the instrument being too dry, causing the top to belly upward excessively. The pics below show in more detail. Apparently the bridge had been repaired prior, although I couldn't see any sign of it. All that had been left were scratch marks and glue residue.
After removing the bridge it had to be planed flat again. The second picture shows how badly warped it is. The areas unaffected by the sanding are warped upward significantly (several millimeters). After tons of elbow grease, I got 'er planed flat again - ready to be reinstalled.
This reglue was a challenge mainly because of the shape of the bridge. All the protruding edges have the tendency to pull upwards on a bulged top (or a top less than flat). I was successful in reseating the bridge - using epoxy for it's strength. Anything less would not work.