Building bridges

I finally finished the lacquering on three guitars.  Now they need to cure before I can wet sand them.  I’ve been doing some odds and ends while I’m waiting.  Just a little guitar stuff, like the bridges.

I roughed out the bridge blanks a couple weeks ago.  To slot for the saddle I decided to make a fixture that held them at an angle.  The router sits in the fixture with very little play.  The length of cut is set by the stops on the end.  To hold the bridge in place I made a couple wedges.  Yes thats right folks… dual wedge action!

Then I measured the nut and 19th fret on each guitar and laid them out on paper (they were pretty close) to make sure my string spacing was ok.  Since I had three, I made a drilling template.  Of course I used plexiglass, which seems to be my favorite.  For precision, I like to scribe things, and plexi scribes really well.  I laid out a center line and scribed distance from the rear of the bridge to the pin centers.  I used a drafting divider to scribe pin centers.  I used these from both outside strings to make sure they matched.  Then I lightly punched the centers and drilled with a brad point bit.

To align the template, putting the scribe lines down, I matched the template and bridge center lines (this is why I like see through plexi) and made the rear flush, then clamped each end and drilled.

To shape the wings, I contemplated using a small 1” belt sander I have, but I figured by the time I rigged something up to keep the bridges square, I could be finished.  So I just did them with a rasp and scraper.  It was quiet, no dust flying, and enjoyable.  Also got one of those gunstock vises.  It was really helpful for these.

I was actually surprised how close I got three of them doing it essentially by eye, but I did gang them together to scrape and sand them even closer.

I don’t have a countersink for wood, but I sharpened up my metal countersink with a file, then countersunk all the bridge pin holes.

I fit the saddles in place and the ends were marked with a drafting french curve so the saddle looked decent transitioning into the curvature of the bridge wings.

Then I shaped the ends on a small sanding drum chucked in my drill press.

I sanded the bridges down to 1500 grit.  No finish on the rosewood.  The rest of the saddle shaping and polishing will come later during set up.

I love the white (and semi dusty) window sill for pictures.  Too bad I can’t photograph anything much bigger than the bridges in there.

Now I wait for the finish to cure for a few more days.  This coming weekend should be two weeks, so I think I should be able to start wet sanding.