1923 Martin 2-17 repair (June 2020)
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. This is not unusual since the lightly-braced instruments were not prepared for the stress of heavy gauge steel strings.
This is the bridge that came with this repair. Even though this tie bridge doesn't require bridge pins, there were holes in the top that had previously been filled.
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.
 
In a previous repair, someone tried to reduce the bulge on the top by gluing the top and bottom to these two mini pillars. Even if it worked, imagine the effect on the sound.
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 was a bit of a mess, too!
I removed the upper tonebar to get at the large lower brace that was also glued in a previous repair in an attempt to level the top. The lower tonebar was cracked, so I removed it along with the broken bridge plate.
New maple bridge plate and spruce tonebars. I opted for a more robust bridge plate to help the top "remeber" its previous profile.
 
I further carved and tuned the tone bars before re-assmbly.
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.