Gibson LG-0 Plastic Bridge

I have to laugh whenever I read the words "special bridge", but that's what Gibson called their hollow, bolt on, plastic bridges which were used from the early to mid-1960's on their Gibson LG-0 small body guitars.
They were special alright. lol

Plastic Gibson bridge replaced with handmade ebony bridge

These bridges were not glued to the top, instead, 4 screws pass thru the bridge plate and screw into the bottom of the hollow bridge.

Screw holes

Compounding The Problem


Unfortunately the hollow plastic bridge wasn't the only issue this instrument had working against it. Couple the hollow bridge with a soft spruce bridge plate and ladder braces and you begin to understand why many have developed problems.

Excessive top belly (upheaval) 

Loose ladder bracing contributes to problem  

Here we see a Gibson LG-0 guitar which was braced with ladder braces (parallel bracing resembling rungs of a ladder), a spruce bridge plate (most are made with maple or rosewood) and bolt on plastic bridge.

A feeler gauge shows a loose brace which has really exasperated the condition. Without the structural support of the braces the top is free to pull upward and create what we call "belly". While a certain amount of top bellying is normal on aging acoustic flat top guitars, excessive bellying is often an indication of a problem.

Cracked screw hole

Plastic Likes To Crack & Warp


When a top deforms it makes it difficult for the bridge to conform to the changing shape. This can cause the top and bridge to part ways. For a bridge made of wood that means a failing glue joint. On our plastic bridge this means warping and cracking.

Often we see the delicate screw holes crack or completely sheer off as the aging plastic looses it's battle against tension. Gluing and repairing a cracked plastic bridge is a lesson in futility, especially when other issues are present.

A warped plastic bridge

An Interesting Re-Repair

This mahogany topped Gibson LG-0 came into the shop with a replacement bridge already in place. The problem? It was a Guild bridge! Obviously everyone who does guitar repair does not make replacement bridges from scratch. When that is the case they often resort to whatever they have on hand.

While this one certainly looked bad cosmetically, it also produced very poor intonation. The instruments saddle slot must be precisely located to allow the instrument to play in tune up and down the neck.

LG-0 that had a Guild bridge installed. Note the original screw holes.

With the Guild bridge removed I was faced with a large area where the finish and some wood had been removed. This area would have to be touched up as a complete top refinish was not in the budget.

I created an oversized ebony replacement bridge to not only cover some of the  previous damage caused by the Guild bridge, but it also added additional mass behind the bridge pin holes. Look again at the plastic bridges and see how closely the bridge pins sit to the back edge of the bridge. That may work on plastic but it isn't going to cut it on a wood bridge.

An oversized ebony bridge is used to conceal the damage done by the Guild bridge

See my photo gallery of bridge replacements