Gibson Bridge Plate Repair:
As you may or may not know, an essential element of acoustic guitar bracing is that of the Bridge Plate. The bridge plate, which rests directly under the bridge on your guitar, executes a number of crucial purposes. It reinforces the sound board under the bridge, provides a surface for the string ball ends to rest against, & acts as a tone transfer point (if fitted correctly) between the bridge, strings, top, and braces. The image below is a fairly average x-brace pattern found in most acoustic guitars. The bridge plate is the rectangle with the holes in it fit into the X.
Over time, the pull of the strings against the bridge plate eventually causes it to wear. Bridge plates are usually made of hard maple (and sometimes rosewood) so that it can handle the constant pressure of the metal string ball ends. At some point, every bridge plate needs repaired or replaced. I personally feel that, except in the case of a completely cracked though plate, repair is preferable. This Gibson came in for some routine fret work,- but upon assessment I discovered an incredibly damaged bridge plate. The plate was also made of spruce – not the best material choice!
This picture is taken from inside the guitar. You can see the tremendous damage to the soft spruce bridge plate. The balls had pulled all the way through and were resting directly on the sound board. Another year or less like this and the bridge would have likely torn off, tearing up the soundboard in the process!
My fist step was to clean up the break area (not shown) and plug it with a new piece of spruce.
Here’s the plug before it went in:
Once I had the fit just perfect, I used a cam clamp, plexiglass call, and hide glue to install it.
Using a small sanding block followed by a razor blade scraper I then cleaned it up flush with the bridge plate.
The next steps was to make maple bridge plate overlay. This was especially important on this guitar because the soft spruce bridge, if left with just the matching spruce plug, would have just worn down and chipped out again .
Step one was to dimension and size the overlay.
Then to thickness and size a piece of hard maple for the overlay, drill holes for the bridge set screws, and taper the edges..
I made a custom hardwood caul, rubbed with paraffin wax to prevent sticking, to install it. Again, hide glue was used.
Installed with cam clamps, you can faintly see the plexiglass caul on top to help spread the pressure out.
I let the hide glue set up overnight, cleaned up any excess glue, reattached the set screws, and then re-drilled the bridge pin holes.
The final step was to taper the bridge pin holes so the pins fit just right and then establish a groove for the windings with a needle file.
Thanks for reading!