Brace Reglue on a ’37 Gibson J-35

January 13th, 2022

A structural issue we often discover on instruments that have had a bridge reglue in the past is a separation of the X brace and top directly under the bridge wing. This can happen as a result of the heat that’s used to remove a bridge, or can happen from improper clamping when the bridge is reglued. It’s easy to miss, but can spell eventual top collapse if it’s not fixed.

This ‘37 J-35 is a perfect example if this issue. It’s flawless inside except for one sneaky loose section of X brace right under the bass side bridge wing. The challenge with this otherwise simple glue up is that the clamp landed right at the seam of the slope of the bridge wing and the top, and there was no good way to to safely clamp.

Showing a loose brace under the bridge on a 30's Gibson guitar

This wing/top caul took 10 minutes to make, and ensures a safe and accurate glue up. The notched caul on the brace itself is cut to fit snugly over the brace and is specifically made for 30’s Gibsons, which I work on a lot.  It’s drilled on the back side to index with a Stewart MacDonald clamp, and it’s small enough to allow for easy clean-up of glue squeeze out.

When gluing a loose brace you get one chance to fix it properly.  It’s never guaranteed to hold if the repair fails and you have to glue it again, so it’s worth the extra time to give it its best chance of holding tight.

Showing a caul used to glue loose braces under the bridge on a 30's Gibson guitarShowing a caul used to glue loose braces under the bridge on a 30's Gibson guitar

Leave a Reply

Your email address will not be published or shared with any third parties.
Required fields are marked *