Next on to a more scary glue joint--the bridge. According to gospel, this is the most crucial glue joint in the entire construction process. It's said that the bridge has to bear the forces of nearly 200lbs. of string tension trying to shear it off of the soundboard, so naturally the quality of the glue joint is of concern. However (and I could be completely wrong here), unless you're doing a string-
thru bridge (which does not use bridge pins) I don't think the forces acting upon the bridge are that strong and exclusive. If you think about it, the ball of the string is actually pinned so that it makes contact on the underside of the soundboard, so the shearing force is actually
transferred and thus shared but the "bridge-sandwich" of the bridge, soundboard, and bridge plate. I think a string would effectively rip a gaping hole through all of these laminated pieces of wood before the bridge was simply sheared off. But who knows. In any case, I intend to have incense lit and pray at least three times, followed by profuse and humble bowing before attempting to execute this glue joint.
But before the praying commences, I have to locate where the actually glue the bridge down.
The bridge's exact location is actually subservient to the precise location of the saddle. Failure to exactly locate the saddle will result in impossible intonation, since you're effectively setting the string length which is what allows for intonation. The tricky thing here is that the saddle must be exactly twice the distance from the nut to the 12th fret, PLUS a specified amount of compensation to account for the increased string tension occurring when a note is fretted, which acts like a pitch "bend."
Locating the bridge involves the projection of the fingerboard's center line to determine the bridge's center line (it's not necessarily exactly the center line of the guitar body, mine is about 1/32" off), which doesn't really matter. If you can eyeball that my bridge is 1/32" off to the right, that's awesome. I can't. But I can be sure that when I string it up my low E string won't slide off a crookedly aligned fingerboard when I play. One method involves painstaking measurements to the 100th of an inch, in several triangulated directions to find the exact NASA approved spot for the bridge...
Or you can by a "Saddle-matic" (I didn't name it)
Basically this
geniusly simple
alignment tool can be bought from
StewMac for under $20. You position it on the 12
th fret and set its distance from the nut to the 12
th fret and lock it in place. Then you turn it 180-degrees to where the bridge will go, with the 12
th fret as the pivot point. The beauty here is that at the end of the block are two protruding pins that you set to be the extra compensation distance, and presto, assuming you checked for a
center line, that's where the bridge goes! Trust me, this little tool is worth every penny.
Once I was comfortable with the bridge's location, the next trick is to gently scribe its location into the soundboard's lacquer--but not too deeply so you don't see it as a scratch in the end--and proceed to taping and scraping.
The scribed line is barely
perceivable, but it's there. Next for some tape:
After about an hour or so of careful scraping, (approximately 1/32" to the inside of the edge), here's the soundboard denuded of lacquer:
Now as happy as I am with Ghost Bridge, I decided I had to get the bridge on before calling it a night. The book calls for one 4-1/2" deep C-Clamp and 2 wooden cam clamps--hah! maybe if you have a ton of cam clamps and happened to have some small ones--I couldn't get them all in the sound hole, so I had to make a late night hardware store run--fortunately they had some more 4-1/2" C-Clamps. You should clamps it all together without glue first as a dry run to make sure you have all the necessary tools ans set up--I'm glad I did.
Here're some bridge-clamping-in-place-please-don't-blow-up-Mt. Rainer-for-at-least-an-hour pics:
4-hours later (actually the next morning) and it was like
Christmas (or
Hanukkah, or
Kwanzaa, or whatever) This time when I picked up the guitar to move around the bridge didn't fall off and threaten to slide under the refrigerator...
