Bridge Plate Repair
Bridge plates are most commonly made from maple or rosewood and less frequently, spruce.
String ends seated firmly against maple bridge plate.
While the size and thickness of bridge plates differ, it's purpose is to reinforce the top and keep it from bellying (arching) excessively at the bridge where the strings place incredible tension on the top.
Common Bridge Plate Problems
Wear and Tear Around Bridge Pin Holes
The ball end of the strings should hook around the edge of the bridge plate and be held there by the bridge pin. When the hole is enlarged by wear, the ball end of the string often pulls itself up into the hole instead of against the plate.
Why do my bridge pins want to pop out when installing new strings? The ball end of the string wears away at the bridge plate, causing a once round hole to take on a keyhole shape. This wear permits the ball end to pull "up" into the plate and does not allow them to lock against the plate.
When the ball end of the string no longer catches against the plate it often results in flying bridge pins.
Another commonly seen symptom ...the thicker string winding which wraps around the ball end can now come close too or even touch the saddle. When this occurs the saddle may incur damage and intonation may be affected.
The string's end winding is contacting the saddle.
This can cause excess wear on the saddle and problems with intonation.
Warped Bridge Plate
Many believe that smaller, thinner bridge plates attribute to good tone. They may also suffer from warping and cupping after years of string tension.
Several manufacturers have flip flopped when choosing bridge plate size and thickness. The catch 22 here is that smaller, thinner bridge plates sound good but often lead to more costly repairs due to top bellying. As a result , certain manufacturers have gone from too small, to too large to just about right thru the years.
A badly warped bridge plate may cause the top to belly excessively or distort in such a way that the bridge can not longer stay glued to the top due to the change.
Cracked Bridge Plate
Though not particularly common, bridge plates can crack. When this happens it often occurs thru the bridge pin holes.
Loose Bridge Plates
When checking for a loose bridge plate I will start by inspecting them with a light and mirror, if any doubt remains I will use a thin feeler gauge to insure there are no gaps present.
Removing Bridge Plates
As many of you have guessed, removing the bridge plate is not without risk. Heat and/or moisture is often used to soften the glue between the bridge plate and top. Because the top is relatively thin one must avoid overheating the area which can damage more vulnerable finish such as lacquer.
Unfortunately accessing the plate thru the soundhole leaves room for little else ...like mirrors. This is one task that is, for the most part, done by feel.
I use a number of hand made tools which allow me to work my way under the bridge plate and separate it from the top.
Once removed, a new bridge plate is made from scratch and glued in place. To avoid splintering the bridge pin holes (which is commonly seen on inexpensive instruments) the new holes are drilled undersized and reamed to the correct dimensions. Tear out, which is often seen when the holes are drilled improperly can promote premature bridge pin hole wear if chips and tear out occurs around the hole.
Repairing Worn Bridge Plates
While warped, cracked and loose bridge plates should be replaced, worn bridge pin holes can be repaired without replacing the plate in some cases.
Gibson guitar bridge plate showing signs of wear.
Note the screws which go thru the bridge and are hidden beneath inlay.
I have used a couple of different methods to repair worn bridge pin holes including plugging and re-drilling them. For simple wear and tear however an easier method is to install a PlateMate© which will completely cover the worn holes.
Rosewood bridge plate with PlateMate© installed
allowing the strings ball end to catch securely on the edge of bridge plate.
It can be very aggravating trying to string a guitar who's bridge pins continually pop out when string tension is applied. To lessen the effect I recommend you put a gentle bend in the end of the string at the ball end which will encourage it to hook and lock onto the edge of the worn hole. You can also turn a fluted bridge pin around, placing the groove away from the string to further close the gap as well.
Acoustic Guitar Repairs
- Action / Set Up
- Bridge Plate
- Bridge Pins
- Buzzing - Noise
- Care / Maintenance
- Convert Rt. to Lt.
- Fret Replacement
- Fret Types
- Neck Damage / Issues
- Neck Angle
- Neck Resets
- Part Glossary
- Strap Buttons
- String Changing
- String Choices / Effects
- Truss Rod
- Tuning Machines
- Tuning Troubles