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glue the bridge before of after spraying?
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=2684		 Page 1 of 2
Author:  Barry Dudley [ Tue Aug 02, 2005 8:48 am ]
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I have always used a brush to apply my finish and always glued the bridge on after I buffed it out. I just got a spray set-up and am about to spray a guitar. Do I still want to glue the bridge on after?
Author:  RussellR [ Tue Aug 02, 2005 8:49 am ]
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Barry

I would glue after you just won't get a clean line around it masking it then spraying.
Author:  Brazilwood [ Tue Aug 02, 2005 9:12 am ]
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I always sprayed the finish on first (nitro cell) then marked the placement of the bridge with masking tape. Take an exacto knife and scribe just inside the masking tape lines to the shape of the bridge (make sure your scribe line goes to the wood. Otherwise the finish will chip off outside the scribe line. Then DELICATELY strip away the finish with a sharp chisel to expose the raw wood again under where the bridge will be glued. Rough sand the exposed wood where you chip away the finish. Rough up the bottom of the bridge with (again) an exacto knife to give the glue more bonding surface. Then apply glue to the exposed wood on the top and clamp the bridge in place. Wiping the squeeze out with wet qtips and after 20-30 minutes use a sharp edge of a small metal pocket ruler to CAREFULLY clean the remaining squeeze out. But be careful not to scratch the surface with the edge. This leaves a very clean edge and no exposed glue around the bridge. You may need to do this several times because the glue will continue to squeeze out until it starts to set. That's always been my technique and never had a bridge come off or lift after many years. Just my two cents.
Author:  SStallings [ Tue Aug 02, 2005 9:49 am ]
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I have a very basic question as a newbie related to this. Why isn't the bridge finished? Everything says that no finish is put on the bridge but the reason why is never explained. Just curious.
Author:  Brad Goodman [ Tue Aug 02, 2005 10:15 am ]
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A small percentage of builders do finish their bridges-mostly classical.
Author:  RussellR [ Tue Aug 02, 2005 10:23 am ]
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I think probably the reason for it is two fold first of all the types of materials used for bridges will usually polish without the need for a finish and don't need protestion from the enviroment. Secondly it would be very difficult to achieve a high level of finish on every aspect of the bridge and around it.
Author:  Brazilwood [ Tue Aug 02, 2005 10:40 am ]
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I agree with Russell on both parts. The bridge is usually a hardwood as is the fingerboard. A high polish look can be obtained without finishing. Also, I think since the top is so important in the sound of the instrument, the less weight and restriction of movement, the better the instrument will resonate.
Author:  SStallings [ Tue Aug 02, 2005 10:52 am ]
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Playing devil's advocate: if the bridge can get a high polished look without a finish since it is a hardwood, why finish the backs and sides which are also hardwoods? That explanation does not justify it for me. The second reason--that it would be hard to get a good finish on all parts of the bridge seems to be negated by the fact that bridges are sometimes finished on classicals. The final reason--that it affects the sound--sounds reasonable, if it does. Not trying to be difficult about this but am just curious about the reasons since it would seem to be easier to glue the bridge to to the top and then finish rather than finish, remove the finish at the bridge and then attach the bridge. Seems like this is the way it is always done, however.
Author:  RussellR [ Tue Aug 02, 2005 10:59 am ]
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On the first one I would say the bridge is a small surface area and barring the wings is pretty thick compared to the back and sides, and remember we are dealing with naturaly resinous woods on the bridge. Not so in the case of back and sides.

As for the argument on the finish on classical bridges, my understanding and maybe one of the classical experts will correct me if I am wrong are either hand finished, or finished before being joined to the top.
Author:  RussellR [ Tue Aug 02, 2005 11:18 am ]
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Sorry Stephen

I just read my last post and it reads a bit abrupt it was not intended to be.

I think the great advantage of a forum like this is we can have a good discusion on all of these points.

Author:  Brazilwood [ Tue Aug 02, 2005 11:25 am ]
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The back and sides wouldn't necessarily need to be finished. However, it is for the preservation of the wood and the overall guitar as well as cosmetic appearance. I can't imagine what your guitar would look like after a few years without a finish. The oils from your hands, exposure to moisture and other natural elements would take a toll on the overall instrument pretty fast. As for an unfinished bridge and fingerboard, I regularly treat them with Orange Oil to keep them from drying out and cracking. Plus it brings back the natural luster of the wood. Heck, as far as that goes you really wouldn't need to apply a finish to the top if you didn't care about preserving the wood or the appearance ???? It's all in your personal taste and experience. Try both for yourself and see which suits your style and results in a better instrument. The proofs in the puddin..I always say.
Author:  SStallings [ Tue Aug 02, 2005 11:27 am ]
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No offense taken. As someone who has been doing this for a rather short time, certain techniques and procedures--in my mind--raise the question "why?" I think it is important to understand "why" to really understand this craft.
Author:  RussellR [ Tue Aug 02, 2005 11:30 am ]
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Stephen

You are totally right to ask why both for understanding and to ensure we keep pushing ourselves to find new ways of doing things.
Author:  SStallings [ Tue Aug 02, 2005 11:32 am ]
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Brazilwood: I'm not questioning the reasons for finishing the back, sides and top. It goes without saying that appearance and preservation are reasons for finishing them. My question is much more basic--why isn't the bridge normally finished?
Author:  Barry Dudley [ Tue Aug 02, 2005 12:17 pm ]
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Well if your going to french polish it is so dificult to do a really good job with the bridge attached. Classical guitars traditionally were FP. The bridge isFP seperately and you remove the finish just as someone pointed out the glue the finished bridge onto the finished guitar. But spraying the guitar it seems that gluing the bridge in place and then spraying would work better. Is there anybody who does glue the bridge and then spray?
Author:  Brazilwood [ Tue Aug 02, 2005 12:49 pm ]
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There is another reason I could see for not applying the bridge before spraying. I have done a lot of finish work and spraying with the bridge on wouldn't really be the issue. It's the buffing of the guitar afterwards. Most builders I know don't French Polish, use a buffing wheel to buff the guitar in the final finishing stage. I think you would also find it more difficult and maybe even problematic to try and buff the top with the bridge on. There could always be a chance of hanging the wheel on the bridge and yanking it out of your hand and slamming it on the floor (Which I have seen happen). Also, it would be more difficult to get a good buff close to the parts around the bridge. These fine detailed areas are where you usually notice imperfections and can see a difference in the detail work with experienced builders. Again, just my personal take on the potential reasons.
Author:  D.L.Huskey [ Tue Aug 02, 2005 3:50 pm ]
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I glued a bridge on once before finishing, being very careful to mask it completly. After finishing the tape was removed and a very small unfinished line remained all way around the bridge, and not being able to properly sand between coats around the bridge didn't help either. Then trying to buff around the bridge was next to impossible with less than satisfactory results. I wouldn't do it again. It's much easier to remove the finish to glue the bridge.

As for finishing the bridge, I did this also, but I used a matt oil finish on the bridge. This was a cherry bridge and I wanted to protect it from becoming grimy from handling.

I wouldn't use nitro or anything as such to put on a bridge because of being too easy to scratch and wouldn't look good after a few string changes.
Author:  Mattia Valente [ Tue Aug 02, 2005 5:46 pm ]
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Another reason not to finish a bridge: it looks nicer, won't get weird smudge marks and fingerprints all over it, but above all, it feels nicer. Glossy finishes ain't comfortable to me, and if they can be avoided in spots that don't need them, I say go for it. I dislike maple 'boards mostly because of the finish, and I really don't like gloss laquer finished necks much at all (shellac or oil for me, thanks).

Besides, honestly, a warmly polished but not finished rosewood bridge looks nicer than anything that's been glossed up.
Author:  crazymanmichael [ Tue Aug 02, 2005 5:59 pm ]
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one other reason for spraying and buffing out before affixing the bridge is the problem of finish build up in the joint angles, just as it is with the neck. it looks bad, and can't be sanded out well. in building traditional classical guitars with french polish the bridge, head stock and neck heel areas are finished before the large areas and even though small in area probably take four times as long to do as the rest of the instrument, i.e. PITA
Author:  Dave Rector [ Tue Aug 02, 2005 9:46 pm ]
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Hmmm, I do use finish on my bridges. I rub on several coats of shellac then buff it down with some steel wool followed by a trip to the buffing wheels. Then I radius the bottom before gluing it on.

To me it just look a little more finished than if I leave it raw and just buff it. It also seems like it needs some sort of protection, everything else does.

I also use StewMac fingerboard oil on my fingerboards, so really nothing on my guitars is bare wood. Maybe that's why they sound like a strung up 2x4.
Author:  Barry Dudley [ Tue Aug 02, 2005 10:55 pm ]
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You have brought up some points that make sense to me. Buffing with the bridge being attached, sanding and build-up at the joint are all great reasons. One method I have used is to tape where the bridge goes and finish over the tape. When I'm ready score the finish at the edge and peel the tape off leaving the bare soundboard exposed ready for glue. Has anybody tried that method? It keeps you from having to scrape the finish where the bridge will be glued.Barry Dudley38567.3312962963
Author:  Mattia Valente [ Tue Aug 02, 2005 11:08 pm ]
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I know some folks mask a little inside the bridge's footprint (say 1/16" or so), buff, then scribe around the actual outline and remove what little finish still needs removing. Sounds like a doable plan to me. The problem I see with taping off the entire bridge footprint is that you might still get a bit of a 'ridge' at the edge of tape and finish.
Author:  Michael Dale Payne [ Wed Aug 03, 2005 12:07 am ]
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Finish solvents can melt and pull the adhisive out from under the masking tape there by contaminate the area around it. I know several Luthiers that do this with good results, but there are lurking hazards to be carfull of
Author:  rlabbe [ Wed Aug 03, 2005 12:26 am ]
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While all the concerns above are valid, I'll point out that classical builders regularly finish the guitar after the bridge is on; furthermore, our necks are already attached, fingerboards glued down, and, depending on the builder, fretted. This all imposes a challenge, but a surmountable challenge.

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