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Tuesday, November 6, 2007

Ready for neck and bridge glue up.....

I spent some time getting the bridge location exact with locating pins set and re-setting the neck. After all the lacquer work, the neck had shifted a little so I needed to get it reset. It was off to one side, and it had also tilted back a touch. Nothing major, but enough that it needed addressed. I also repaired the small sand through spot on the side and got that sanded down and polished.

I learned a little trick on the OLF site about getting a good looking finish line around the bridge. One of they guys showed one of his bridges that he had routed a very fine rebate around the very edge of the gluing surface of the bridge. What this does is allows the luthier to glue the bridge to the body without having to scribe the finish perfectly around the bridge. When I mask the bridge off, I keep the tape inside the bridge line by about 1/16". I have been scribing around the bride and scraping that last little bit of finish off before gluing. This is a very hard thing to do and make it look good. With this system, the finish now can remain that 1/16" under the bridge without putting stress on the glue joint. It is a very simple solution to the problem that makes me wonder why I never thought of it! I made a little jig to attach to my dremel which turns it into a tiny router station. I used a 1/8" downcut spiral bit poking through less than 1/64" with a dowel that covers about 1/3 of the bit. That gives me a channel a touch wider than 1/16" and as deep as the finish is thick. I ran my bridge through it and tested it on my guitar. It worked great! I am attaching a few pictures so you can understand what I am talking about. If time permits, tomorrow I will set the neck, and possibly will glue the bridge down.





Here is the little bridge jig I spoke of.


Here you can see the bit just poling above the base. It is just a hair above the base because I only want the rebate to be the depth of the finish thickness.


This is the under side of the bridge showing the rebate. The picture makes it look a lot deeper than it is. It is less than the thickness of a piece of paper deep. I took the picture with a shadow so you could see the rebate. I also sanded the bridge to the radius of the top.


Here you can see how the finish slides neatly under the bridge. This doesn't weaken the glue joint at all. If you click the picture, right under my fingers you can see the finish to bare wood line. That is what I typically end up seeing and what I am attempting to avoid.


Here is a picture of my ever growing wood stash. I have 7 back and side sets, 7 tops (2 more on the way), 5 fingerboards, 6 bridge blanks, 2 neck blanks (3 more on the way), 8 rosette blanks, and about 30-35 headstock veneers. I also have a bunch of brace wood not shown, and some heel and neck blocks. The side wood you see on top is the black limba. It is incredible looking wood as is the curly cherry I got at the swap meet. It is beautiful wood.

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