One of my best customers asked me to put a bridge on his guitar. The guitar is a Martin 2-17, built in 1923. The 2-17 was Martin's first venture into steel strings but this one came to me with a classical bridge made of Brazilian rosewood that had been pulled off.
I took a look inside, and then things got interesting. There were two large wooden blocks glued to the back and an additional huge brace glued to the top.
There were wooden pads glued to the top that corresponded to the wooden posts, but there was also a considerable gap, so the posts were ineffective. (And that's assuming they had a reasonable purpose in the first place.)
I decided to remove the back in order to take care of the problems on the inside.
I used heat and several blades to carefully remove the Brazillian rosewood binding so it could be re-used.
The binding was very thin and delicate.
Once the back was off, the large blocks on the back and the strange brace on the top contributed to making this an interesting repair. The back had several cracks. I made some cleats out of mahogany and filled the cracks with liquid hide glue.
The top showed holes for bridge pins that it seems someone tried to fill, so this was not the original bridge.
I removed the top tonebar to get at the large brace. The lower tonebar was cracked, so I removed it and the broken bridge plate.
At first glance the top seemed to have only a slight dome to it, but when I put a straight edge along the fingerboard, the geometry was off.
Finally, I understood why the previous repair person had tried to pull the top down using those massive posts and brace.
Over several days I used a combination of heat, steam and pressure to gently encourage the top to return to its original shape and it was successful.
The heating blanket caused the finish to wrinkle badly, but using French polishing techniques even 97 year old shellac responded and the finish looks good.
The straight edge on the fingerboard now has a much better trajectory to the bridge. It's a bit early in the process, but I used a piece of ebony to fashion a new bridge.
New maple bridge plate and spruce tonebars. The tonebars were reduced in mass before the back was reattached.
The alignment was still off, so as I reattached the back I placed a slight wedge under the tail instead of doing a neck reset.
This is an approach used by classical and flamenco builders.
With the back in place I used a router to cut a binding channel. I then made rosewood bindings and glued them in place. Used scrapers and a sander to match the bindings to the sides and back.
Glued new bridge in place. I used three clamps and a couple of aligning pins to secure it into place as it dried.
Interesting facts: This wooden clamp was used by the Levin guitar company in Sweden in the 1960s. The scale for a 2-17 is 622.2 mm from the nut to the high e string.
Put on a set of silk and steel strings, light gauge. A restored guitar and a very happy customer.