rock blues guitarist : How to install a guitar bridge and how to angle a Tune-o-matic bridge?

1) Airline Town and Country guitar

Vintage 1960 Airline Town and Country guitar

This is a 1960 Airline Town and Country guitar that belongs to Australian blues guitarist Gerry Joe Weise, the former owner of this guitar had been the bassist from Arizona's Badland, and Gerry Joe acquired this guitar for only $300 in Phoenix.

Due to several tuning problems and guitar strings regularly slipping off the bridge saddles. Gerry Joe contacted me about this problem and we opted for replacing the old bridge with a new 1960s style Tune-o-matic bridge for the vintage look. It is equipped with adjustable intonation screws and height adjustment with threaded mounting posts.

2) Tune-o-matic bridge for electric guitar

Tune-o-matic bridge with studs and bushings in chrome

The Tune-o-matic bridge consists of 2 adjustable posts, that each have a wheel on a stud that screws into a bushing, which are implanted into the guitar body. And a bar called the bridge, is placed onto and between these posts.

The bar has 6 saddles, one per string. Each saddle has a small groove that matches a string shape, and this is where the guitar strings are placed onto. Each saddle can be adjusted, moving them back or forward with a screw to control intonation.

The Tune-o-matic bridge for electric guitars, was originally designed by Gibson and introduced on the Gibson Les Paul guitar in 1954. It was later accepted as a standard bridge on mostl Gibson electric guitars.

3) Preparing the guitar for the new bridge

First take the strings and the original bridge off the guitar. You can see the traces left by the bridge on this guitar in the photo.

NOTE : On this guitar there were no drill holes, as the original bridge was only placed onto the guitar body. If you have holes on your guitar that do not correspond with the new bridge posts, then I suggest you fill them up with wood filler, leaving it to dry before drilling.

4) Measuring the guitar for the new bridge

Use a metal Tape Measure, and place it onto the guitar as in the illustration. I use a metric measurement tape on this guitar repair (I am in Australia right? and we use the Metric System down here), but you may use one in inches. The following calculations in the next steps, are for any type of measurement, both Metric or Imperial.

NOTE : Turn the guitar around to this side as in the photo, so it will be easier to work through all the following steps accurately.

5) Measuring from the Nut of the guitar

By starting from the Nut of the guitar, you can get a full measurement of the whole guitar, to know where to place the new guitar bridge. Make sure you start from where the strings actually leave the guitar nut.

6) Measuring to the 12th fret of the guitar

By starting from the Nut, measure down to the guitar neck's 12th fret.

On this example, we have 31.5 cm. So to find out where to place the new guitar bridge on the guitar body; you double or multiply the measurement by 2, which equals 63 cm in this case.

NOTE : There are several different sized necks for different guitar brands. For example Fender, Gibson, and Airline guitars have 3 different sizes. This Airline Town and Country has a short scale fretboard.

RESULT : It can be any sized neck, as long as you measure from the Nut to the 12th fret. Then multiply the measurement by 2.

7) Measuring to the guitar body

Multiplying the distance from the Nut to the 12th fret (31.5 cm) by 2 equals 63 cm, on this guitar. This is where the new bridge will be placed.

NOTE : You can see the traces from where the old bridge was approximately on the same place.

8) Placing the new bridge on the measured spot

Now place the new bridge in the center of the calculated measured spot, and as straight as possible.

9) The new guitar bridge alignment

You can use pencils as are shown in the photo, aligned with the guitar's pickup and arranged in a straight line. This helps to place the guitar bridge in the middle.

10) The desired angle for the new guitar bridge

Here is the desired bridge angle for intonation compensation.

Why are guitar bridges angled?

Theoretically the saddle, the part of the bridge that supports the string, would be located at exactly the total scale length distance from the Nut. But because the string stretches when fretted and rises in pitch, the string length is increased, to flatten the string's notes to compensate. Because the strings require more compensation as they get larger in diameter, that is why the bridge is angled. This angle approximates proper compensation allowing the saddles to remain closer to the middle of their adjustment range.

11) Measuring the angle of the guitar bridge

Initiating from the center of your Tape Measure and the center of your new guitar bridge (the white lines on the photo), you can tilt your bridge 1 mm to the left at the top of the Tape Measure, and 1 mm to the right at the bottom of the Tape Measure (the blues lines on the photo).

12) Marking the bridge for drilling

When the new bridge is positioned, mark with a pencil in the 2 holes of the bridge, where the drilling for the posts will be.

13) Drill bits

Use a small drill bit, then work your way up in different sizes, to the exact sized drill bit for the bridge posts. This will help in stopping the guitar's wood from cracking or splintering.

NOTE : A good thing is to use red electrical tape on the drill bits, so you can see the desired depth and to prevent against drilling too deep.

14) Drilled bridge holes on the guitar

The result after the holes had been drilled out.

15) Fixing the drilled bridge holes

After the holes are drilled, lightly sand, then lightly stain the bared wood near the top, with acrylic artist's paint using the same colour as the guitar. Wipe the excess paint off the guitar's finish. This isn't necessary, but will lead to a nice neat look, although this will be covered up by the bushings for the bridge's posts afterwards.