Making New Bridge to Replace Plastic Bridge on 1960s Gibson B-25

On the bench today is yet another Gibson with one of those clumsy molded plastic bridges. Some executive…who clearly was not a guitar player and VERY CLEARLY did not understand the legacy of this great brand…thought this would speed up production and cut costs. At least that’s the theory. I don’t know…

**So this is the “before” shot. Guitar top has small amount of bellying, but not terrible. Notice how unbelievably high the saddle has been adjusted.**

**So this is what goes on with these plastic bridges. Those four machine screws go through the top (and bridge plate) and into little molded holes on the underside of the “bridge”**

**See how the bridge is *hollow* underneath?** There are virtiually no points of contact with the body (well, four screws mounts). These flimsy bridges almost immediately began to fail. Tops distorted, bridge plates cracked or broke loose, and strings just got higher and higher off the fretboard.

To make matters worse, this guitar has Gibson’s adjustable bridge installed. I think they started this as an option around ’58. You often see guitars with stamps like “J-45 ADJ”. ADJ means adjustable. These big brass threaded inserts actually fit into the top and are attached with these big nuts. Then the saddlee fits into these adjustable posts.

This is your bridge plate. Look at that damage…They are traditionally made of thin, small pieces of maple or rosewood. This one is made of THICK plywood. As you can see, plywood chips easily. Especially when you drill twelve holes into it (remember, this is a six-string guitar). So now the ball-end of strings are no longer seating properly against the bridge plate. Over time, many of these guitars saw much more damage to their tops and bridge plates than this one.

Some people really love the sound of Gibsons with these bridges. And they are quite lovely, I’ll admit. Tone favors the midrange for sure, without definition or focus. Bass end definitely lacking.

So my customer and I decided that replacing the plastic bridge with a period correct wooden bridge would be the best option. After all, they only used this design for 2-3 years at best. The guitars made prior to this design, and after, all used traditional Gibson “reverse belly” rosewood bridges. So far I have removed all the screws and bolts, filled the six extra holes in the top, reglued a loose bridge plate and glued a thin bridge plate patch of maple to cover all the damage to the original plate. I carefully made a reproduction bridge from Madagascar Rosewood since Brazilian is impossible to find, and Madagascar is considered by most luthiers to be very similar in tone and appearance. The bridge is now glued, but I still need to route the saddle slot.

**Partially through the shaping process. Beautiful grain on this piece.**

If I were to simply make an exact copy of a vintage rosewood Gibson bridge from this era, it would not cover the imprint of the plastic bridge. The dimensions are slightly larger on the plastic bridges, plus over time they warp and dig into the finish on the guitar top. I always carefully contour the replacement to be a clean curve that will both cover the imprint and match the aesthetics of a vintage bridge. It’s always a compromise, so the replacements almost always are just slightly oversized from a vintage example.

I always install two small machine screws to hold the bridge in addition to glueing with hide glue. The screw heads are covered with pearl dots. This is exactly how Gibson made their bridges for decades. I still have some clean up around the edges, and will be routing the saddle slot and making a new bone saddle tomorrow.

I can’t wait to give this guitar back to its owner! Not only will it look better with the new bridge, it is going to sound so much better. Believe me…this is the fourth Gibson bridge conversion I have done since February, and they always always come out with a much stronger bass response, and a more rounded mid-range. More complex overtones and harmonics. He’s going to be happy.

UPDATE: Project. finished, and customer quite pleased.