The Steel String Guitar bridge can be thought of as the forgotten brace.
You take an amazing amount of time to thickness,
brace and voice your top and then you glue a large mass of wood to it.
Therefore, it is imperative that you understand bridge design
and how it affects the tone quality of your guitar.
In this video I will show how to make a standard bridge designed for a steel string guitar.
I start with a bridge blank and thickness it to about 3/8 of an inch or 10mm.
This measurement is subject to your guitar design,
neck angle, and tone you want to achieve
so once again, please study bridge design before attempting to make one.
The 3/8 inch or 10mm measurement is a pretty standard thickness for a steel string guitar bridge.
Next I use a template of the bridge shape
to rough cut the bridge blank to the shape I want.
Then I use a spindle sander to get the exact shape.
Since I am working with a small piece of wood
I do not like using a router to shape the bridge blank.
Once the bridge blank is thicknessed and cut to size,
I mark the location for the bridge pin holes.
Use your plans to determine this location and the correct spacing between each pin.
Use a square to determine the exact location where you will be drilling the holes.
A punch can be used to help the drill bit find its mark.
Drilling six holes in a straight line can be much more difficult than one might think.
If you clamp a straightedge to the drill press table it makes it much easier.
Drill a 3/16th or about a 4.8mm diameter hole using a brad point bit.
These are later reamed to usually a 3 or 5 degree taper depending on the type of bridge pins you have.
You can then slide the bridge blank against the straightedge
you clamped to the drill press table and drill the other holes.
With a little luck they will come out in a straight line.
With the bridge blank beginning to take shape
it is now time to cut the slot for the saddle.
This causes a lot of problems for some folks but it doesn’t have to.
A simple jig like the one I am showing here can help the process go smoothly.
I place the bridge blank in the jig and secure it in place with the screws and washers.
You will notice that there is a shim with an angle on it.
When placing the bridge against this shim
it puts it in the correct position to cut the angle I use on the saddle for compensation.
I will be using a 3/32nd or a 2.4mm carbide spiral bit for making the cut.
I need to use an adapter collet to make the 1/8th inch shank
fit the ¼ inch collet that my router has.
I will be using a plunge router to make the cut but you could also use a laminate trimmer.
Place the router on the jig
and set the stop blocks to the amount of cut that needs to be made to the left and to the right.
This is the width of the saddle slot.
Set the router’s depth gauge to reflect the depth of cut you want to make.
The general rule is that you want at least half the saddle in the bridge.
Carefully turn the router on and plunge the router so that it is making a shallow cut.
Move it across the jig until it hits the stop block.
You can then plunge slightly deeper with the bit
and move the router back across the jig until it hits the other stop block.
Continue this process making consecutive cuts
until you arrive at your desired saddle slot depth.
It usually takes me about 4 to 6 passes to make the complete cut.
This jig really makes it easy to cut the saddle slot to the exact specs you need.
Next I put a radius on the back of the bridge to match the radius of my guitar top.
This ensures a nice fit when gluing the bridge to the top.
You could do this with a scraper
but a radius block with a piece of sandpaper makes the job easier and more precise.
You could also tape a piece of sandpaper to the top of your guitar
and use it to sand the exact radius into the bottom of the bridge.
Don’t apply too much pressure if using this method.
Next, I radius the top of the bridge to match the radius of my fretboard.
Just place the bridge up against the end of the fretboard
and use a pencil to scribe the radius onto the bridge.
This is just a reference line.
In most cases you don’t want to remove material to this line because your bridge will be too thin.
Just use the line to put the same radius on the top of the bridge.
You can use a sander, chisel or even a scraper to radius the top of the bridge.
Next the end of the bridge wings can be tapered down.
A bandsaw works well for this but you could also use a chisel.
If you have a spindle sander it can be used to clean up the cut
and blend the taper into the main part of the bridge.
The top of each bridge pin hole needs to be beveled.
Use a bevel cutting bit in a drill press on high speed to do this.
Make sure that you bevel each hole the same amount.
You can tell this by looking at the diameter of each bevel.
Remember that each hole will get reamed later during set up
so make your sure take this into account when determining how deep to bevel each hole.
If you hold the bridge loosely as you drill
the bit will center itself with the hole.
Now sand the entire bridge progressively up to about 600 grit.
Take your time and make sure that all course sanding marks are removed
before progressing to the next grit.
To give your bridge an extra touch,
use a buffing wheel to buff to a high gloss.
This really put a nice shine on the bridge.