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Paul Hostetter, luthier
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Just a reminder: this is the bridge we don't want anymore: 

Now we make the bridge that's better. Ah!

First I find a nice piece of rosewood that matches the fingerboard, and I trace to outline 
and approximate bridgepin hole and saddle locations using the original bridge. 

I cut the piece out on the bandsaw, true up the gluing face and the long straight side, 
then get the height approximately correct and smoothed off so I can draw on it better. Like this:

The rough end is OK since it'll be gone shortly. 

I fine-tune the bridgepin holes first, using dividers to ensure perfect spacing. 

They must be a precise distance from the back edge, and from the ends, as well as from 
each other. I know the old holes were correct, so that reference saves some work. 

Then I drill the holes with a brad-point bit on the drill press. 3/16" holes are just right. 

Then I lay out the slot for the saddle, making sure first that it is located just right.

Once the slot is laid out, I use a jig on the drill press to route that slot. I use a 3/32" carbide 
porcelain bit. It's very sharp, and at 5600 rpm it doesn't burn, it just cuts a nice clean channel. 

Here's a look at the simple but effective jig. I have made hundreds of bridges with this jig.
It does the saddle angle automatically to any size bridge blank I can clamp into the jig. 
In this photo you can see I have roughed in the wings. I do this on a small 3-1/2" 
drum sander. The top of the center of the bridge is still quite rough.

Now I begin to refine the surfaces of the bridge, starting with the ends and the long curved edge.

Using the bridgepin holes with 3/16" bolts through them as guides, I check the ends first. Remember 
the green masking tape marked exactly where the original ends were. I've left the ends a little long until now. Knowing the bridgepin holes all line up, I can trim the ends closer. Same with the front edge.

Check all sides to make sure the edges all line up. Then proceed to refining the bridge's top surfaces.

The bridge should be higher on the bass side:

remember that this is a *reverse belly* bridge

I finish-sand the surface, and particularly the wings, by hand with abrasive paper mounted to 
fiberglass packing tape. This enables really fine control of spot-sanding, and eliminates the possibility 
of rounding over edges that are best left crisp. I use a succession of grits, from 180 down to 400. 

OK, now the bridge is ready to put in place for a dry run of the glue-up. 

First though, I make a caul for the inside of the guitar, so I can clamp the entire bridge safely. 

I use the bridge as a guide for drilling the #1 and #6 holes in the caul.

The diagonal masking tape marks brace locations; the caul (this one's scrap walnut) 
is shaped to allow me to clamp fully on the very ends of the bridge. The holes line up, 
of course. I carefully clamp the caul into place and redrill the 1st and 6th bridgepin 
holes through the bridgeplate patch and the caul itself to make sure that the 
bridge and caul will be exactly where they need to be at glue-up time.

Now I take off the diagonal tape and go for the final refinement of the gluing surface. 

While the bridge is temporarily but firmly affixed with 3/16" bolts and wing nuts, 
I very carefully score the lacquer just at the edge of the wood. 

You only get one chance to do this right. No mistakes allowed.

The scored line will make the lacquer break like glass.

Below is the business end of a mezzotint rocker. It's a tool art engravers 
use in the intaglio process, and it's real handy for removing brittle lacquer 
and other stuff, and roughing up a surface preparatory to gluing. 

It's about 7/16" wide.

Sometimes I use it like this:

The finishes just shatters and pops off, but it doesn't remove wood. 

I can now use the rocker upside down as a horizontal saw 
to remove all the lacquer inside that scored line:


 

I also use my violin knife, the large one, to clean the back surface. 

You essentially inlay the bridge into a precision hole in the finish. 

Again, no slack. 

The top's spruce is now patched, dead flat, precisely cleaned to 
receive the new bridge, and ready for glue.

Now I put a double-thick pad of cork on the bridge caul; remember, it has 
to absorb the thickness of the patch I put in there. 

A dry run to make sure everything fits perfectly, then the real operation:


 

I run two bolts through to wing nuts inside on the other side of the caul and make sure the bridge 
hasn't slipped. The bolts have "washers" of masonite under regular washers. Then I put on the three iron C-clamps. I do all the cleanup now, while the glue is soft. 
 

This means taking off the tape, and completely washing the entire 
area with warm water. Much easier now than later! Toothbrush, Q-tips, etc. 

After the glue has dried overnight, I leave the caul in and remove the bolts and two of the 
clamps, and use the remaining one to hold the caul in place while I drill clean holes in all six holes. 
I use an 18" long 3/16" brad-point bit for this, because I can work around the clamp this way. 

Do not drill bridge pin holes clear through the back!

The caul prevents tear-out inside. It's usually slightly glued on after the gluing procedure, 
so I can move the C-clamp side to side as I move across without the block dropping off. 

Now the bridge is ready for all the little setup procedures:

  • cleaning the bridgeplate after removing the caul
  • Vacuuming out all the debris inside the guitar
  • fitting the saddle
  • refining the taper of the bridgepin holes
  • chamfering the bridgepin holes
  • putting in string ramps
  • fitting the pins
  • removing the glue and schmutz from the bridge itself
  • removing the glue and schmutz from around the bridge 
  • polishing the bridge wood
  • stringing the guitar up - voilà!
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