Official Luthiers Forum!

I am a newbie. I’ve been setting my guitars up for years. Nut action (files), neck relief (truss rod) and saddle action, inspection & cleaning. Just the light easy stuff.

I enjoy working with guitars would like to grow in knowledge and experience. Building a guitar some day may be in my future.

I recently got a guitar than needs some bridge work and a small crack repair. I have a bunch of questions and I hope some of you will be kind enough to help me.

The bridge was already loose except for 2 Gibson bolts. I got it unbolted and removed without any problems (without removing the bridge inlays and bolts from bridge). I was amazed at how easy the nuts unscrewed. The bottom of the rosewood bridge has some small fibers from the top which I intend to sand to get just down to clean rosewood. The top where the bridge needs to be re-glued looks good to me (what is in good shape with just a few spots were fibers are missing (stuck to the bridge). Some minor scraping/sanding to remove the little bit of old glue is all I assume I need to do to prep the top for re-gluing the bridge (correct?) Pictures are below. Here are my questions:

1. What kind of tape or other material do you use for masking the finished top while cleaning up the bare part of the top where the bridge is to be re-glued? (I see where Stew Mac warns against using their paper adhesive tape on older finishes.) Is blue painters masking tape OK on top finish?
2. I know I need to remove the finish that the original builders missed on the top under the bridge, and remove any remaining old glue. I intend to leave some of the groves in the top instead of taking more top wood away. Do you agree this is best to leave?
3. Since HHG will not work for filling voids (groves in top), I assume I should use Titebond to re-glue the bridge. Is this correct?
4. The scale length should be 24.75” (628.65mm). I believe, since this is short scale and light gage strings will be used, that compensation of 1/16” (1.6mm) on the treble side, and 3/16” (4.8mm) on the bass side of the saddle should be added. Correct?
5. I checked the scale length following a recommendation in Hideo K.’s I measured from the fretboard side face of the nut to the CENTER of the 12th fret and doubled the distance. Is measuring to the center of the 12th fret correct?
6. For determining saddle location, Hideo says to measure from the face of the nut to the FRONT edge of the saddle (sound hole side). I would have expected the measurement to be to the center of the saddle. What is correct way to measure this?
7. How do you keep the glue out of the bridge pin holes? (Use Stew Mc Locating Pins? Or is there a more simple technique?) http://www.stewmac.com/shop/Tools/Speci ... _Pins.html
8. Are slanted bridge pin holes normal? They are slanted so that the bridge pin heads point slightly back towards the endpin. I thought bridge pins should be straight up.
9. Would you touch up the finish around the bridge on a vintage guitar that had no other finish work done on it (is 100% original) or l
10. eave it as it?
11. If I (or have someone else) touch up the finish, should this be done before the bridge is reglued so it is easy to sand flush, etc?
12. If I (or someone) were to touch up top center seam finish break, when should this be done?
13. What is a good source (videos or books) for finish work and other repair (re-fret, neck re-set, crack repair) work?

I’m sure I’ll think of more questions, but this is a good start before I start this project.

Thanks for the help in advance.

Ed

Ed, welcome to the OLF. I don't know the answer to all of your questions, but I've included my replies in the copied text below...



Best of luck to you,

Flori

First, Flori, sincere thanks for your help. My comments/answers are in this color below. Ed.

I'll add my two penneth and I expect to be shot down in flames I've only done around 5 of these repairs and each situation needs gauging differently according to the amount of old glue showing in the tear out of the old bridge.

From your photos there seems to be a lot of fresh wood on the bottom of the bridge now I don't remove this it acts at a ke to getting the bridge back in its original location. Now I use 2 different glues an epoxy glue and cascamite which is powdered resin glue. Both of these glues have good gap filling properties and are creep resistant, cascamite will only bond wood to wood, so you need around 80% fresh wood in the tear out and it should well, if less than that I use araldite amd epoxy glue.

I carefully scrap as much original glue and finish off with a scalpel before gluing, then using the appropriate glue to match the original fresh wood percentage area, I glue and clamp 3 clamps. Probably not the correct way, but my oldest repair is 3 years of more and holding.

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Formerly JJH

I learn more from my mistakes than my successes

I agree for the most part with the afore person, but do not use any epoxy ever unless you know exactly what you are doing. I have known guitar building veterans who have used epoxy to glue a fingerboard to the neck. It will never come off. Never touch the finish of a really old guitar at all unless you have refinished a dozen before, you never know what the finish is made of. Never use more glue than you need, you don't need a lot of sqeeze out to have a good bond. Hide glue and the white guitar building glue from LMI are the best. Never ever use Tite Bond on a guitar as the particular resins in it will make the parts of the guitar far more difficult to heat and pull a part for repair. I've been doing all types of repairs and building guitars for ten years now. No I do not have my own shop and do not work for a guitar retailer. I advertised on my car that I build guitars and people called and wanted repairs done and I do and love it. I french polish all my guitars and I think they sound better than any factory model just as I think any other builders does also.

Jyme, why would that be? I use epoxy for fingerboards and find it is one of the easiest glues to reverse, it responds very well to heat with no moisture.

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David White, Toronto

"All my favourite singers can't sing."

That is not true. I glue all my fingerboards with epoxy and have removed several with heat. In fact, it's pretty easy to remove.

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Peter,

What epoxy brand and source do you use?

Have you ever removed a bridge that was glued with epoxy and if so, how? Was it as pretty easy too?

Your help is appreciated.

Ed

Ed, I have reversed West brand epoxy on fingerboards and it releases very easily...easier than titebond. I have never used it on a bridge.

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David White, Toronto

"All my favourite singers can't sing."