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PostPosted: Tue May 03, 2022 10:40 am 
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Walnut
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Joined: Mon May 02, 2022 1:24 am
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City: Causeway Bay
State: Hong Kong Island
Country: Hong Kong
I did a poor job of masking around the bridge before gluing it and i'm wondering if anyone could share some wisdom on how best to remove the squeeze out that made its way under the tape. The gloss black finish really highlights any marks so i'm afraid to scrape it with a razor.
Would acetone do the trick? I believe the finish is poly.

Any advice is much appreciated.
Thank you in advance!

The guitar had a lifted bridge and a bellied top.


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PostPosted: Tue May 03, 2022 5:30 pm 
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Brazilian Rosewood
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No solvent will remove epoxy. Scraping is your only option but that will scratch up the finish big time. Might want to rethink glue choices next time.



These users thanked the author Barry Daniels for the post (total 2): Hesh (Wed May 04, 2022 2:04 am) • JuanP (Tue May 03, 2022 8:09 pm)
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PostPosted: Tue May 03, 2022 6:30 pm 
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Titebond or hide glue is the way to go....

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These users thanked the author Chris Pile for the post (total 2): Hesh (Wed May 04, 2022 2:04 am) • JuanP (Tue May 03, 2022 8:09 pm)
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PostPosted: Tue May 03, 2022 8:10 pm 
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Walnut
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Thanks for the advice Barry and Chris.

Would you recommend I scrape the excess and refinish with some wipe on poly?


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PostPosted: Tue May 03, 2022 11:27 pm 
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Koa
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I think OP has painted himself into a corner. The epoxy can be scraped away, but I know of no cleanup that will look the same as a bridge installed carefully in the first place. If this problem was mine and I wanted to get it resolved, then I'd have to back up - - - remove the neck and the bridge, repair the soundboard finish, and repeat the bridge and neck installation, this time with Titebond and removing the masking tape after tending to glue squeezeout. Removing an epoxied bridge would be its own adventure.

I suggest OP bring his problem to a luthier and get an expert's hands-on advice as to how to proceed.

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PostPosted: Tue May 03, 2022 11:52 pm 
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Truthfully, Juan - fixing it would probably make it look worse than it does now. Get the masking tape off, and call it good. I perceive this is not an expensive guitar, and doesn't warrant a lot of intensive work unless you are just doing it for the practice.

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PostPosted: Wed May 04, 2022 2:17 am 
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Old Growth Brazilian Rosewood
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It is what it is now and I agree any attempts to remove the squeeze-out is likely going to make it worse (appearance) and you will lose more money if this is a repair that someone is paying you to do.

We ep*xy bridges ONLY as a last resort on instruments that would be thrown in the burn pile otherwise. We wipe any squeeze out up with plain water and persistence and it has to be cleaned up before the ep*xy cures or you are SOL (**** out of luck).

I can only recall one ep*xy bridge reglue that we did in the last three years out of close to 100 bridge reglues in that time and this one was on a guitar that was donated to a homeless person in Ann Arbor named Travis who we keep in beater guitars. Travis is a vet who can't walk down the street without scanning the roof tops for snipers and such. We befriend him nearly ten years ago. He lives outside even in the winter making ep*xy a good choice for his Yamaha.

If this guitar pictured was brought to us now we would turn it away and not get involved.

Long ago we made the judgement that gluing a bridge as simple as it may seem to many is an operation that requires a high degree of skill and the ability to obtain an excellent fit prior to deploying the glue. It also requires excellent workmanship AND planing since with HHG clamps have to be set in 15 seconds or less.

Prep work is everything removing the old glue from both guitar and bridge bottom and expanding the gluing surface on the guitar side to very near the bridge perimeter is what we do for maximum wood-to-wood gluing area.

But it is what it is now, ep*xy is not a good choice for bridges unless again it's a beater instrument and no one cares.

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These users thanked the author Hesh for the post: Chris Pile (Wed May 04, 2022 6:35 am)
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PostPosted: Wed May 04, 2022 2:20 am 
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Old Growth Brazilian Rosewood
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Also what did you do about the belly and did you inspect the bridge plate and more specifically the pin holes for excessive wear and what we call "tenting" where the pin holes create a line for the plate to start to fold on? Loose braces can cause a bridge to lift too as can excessive heat, cold, humidity or lack of humidity.

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These users thanked the author Hesh for the post: Chris Pile (Wed May 04, 2022 6:35 am)
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PostPosted: Mon May 09, 2022 3:26 pm 
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Walnut
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If you're going to use epoxy again on a bridge reglue, don't mask it. There is no need. Remove all the tape and then apply the epoxy and clamp the bridge in place.

Use Q-tips to wipe off any squeezeout around the bridge after you put your clamps on, and if there are any stubborn spots, dampen the Q-tip with mineral spirits. It will take it right off. But you want to be sure it's taken enough of a set that the mineral spirits won't creep under the bridge and affect the integrity of the joint.

Also FWIW, if using epoxy, use CA glue to harden the top first, especially if you're working on a plywood top. The CA glue will secure the plies together and make for a much stronger final joint. Basically the CA unifies the plies and turns them into a cohesive surface for the epoxy to bond to. If you don't do this, the plies are likely to come up again in time, as epoxy is very thick and will not penetrate to the deeper plies like CA glue will.

As for dealing with the guitar in the picture, all solutions are extremely time consuming and likely to have lackluster results, even with extreme care. A Kovax sanding block with a small strip of sandpaper, wet sanding with water and Wool Lube / Detergent, can get the epoxy off eventually, but you'll have to buff out the surrounding area after, and also be extremely careful to avoid going through the clear and especially the color coat. And the finish on that top does not look very thick.

The most likely scenario is you'll make some progress with that and it'll look good, then a couple swipes of wet sanding too far, and you'll see a nice patch the color of bare wood, which will look horrible against the black.

If you're comfortable using an airbrush, you could mix up some black pigment *and* black dye, and do a partial refinish. Black is, in my opinion, the easiest color to touch up, and the easiest color to mix (aside from pure stark white), so if you wet sanded down around the bridge, even if you went to bare wood, doing a refinish with black nitro would not be that difficult, except for one thing --

The bridge of complicates that greatly, and even with careful masking, you're going to get black lacquer onto the edge of the bridge closest to the top, and attempting to remove that even very carefully with a Q-tip dampened with lacquer thinner, you're probably going to mess up the area you just refinished.

What I just described sounds fairly straightforward but that could easily turn into 6 or more hours of mayhem and frustration with the possibility of ending up with something that looks worse than it does right now.

If you're not very comfortable and experienced with wet sanding and buffing, I'd just leave it alone. The most I'd comfortably do would be a quick wet sand and buff, and that would just be for a very modest improvement in appearance. To knock the epoxy down just a bit, which can take some of the harshness away from those lines, and buffing it out to a high gloss will help make it less obviously different from the surrounding area.

However -- the clearcoat looks very thin on that top, and even with a quick wet sand and buff with moderate to fine grit paper, you run the risk of going through the clear and color coat and exposing bare wood. That will be REALLY obvious, and at that point you'll wish you just left it as it is right now.

Some of my favorite guitars are beaters. My main acoustic these days is a cheap 100 dollar something or other that had the headstock broken twice, and was epoxied back on. And not cleanly! You can literally see gobs of hardened epoxy around the entire joint and there was no touchup work done at all.

But it plays great. It doesn't sound great and it doesn't look great, but I don't need it to.

I hate telling people to 'leave it,' but it's a rule I've violated more times than I can count to my own detriment. If there was a really thick clearcoat on there I'd say you could probably get away with a fairly aggressive wet sand and buff to at least blend that hardened epoxy in a little bit so it wouldn't look so obvious, but that can quickly go awry with a thin clearcoat. Don't ask me how I know ;)


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PostPosted: Mon May 09, 2022 3:51 pm 
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^^^ I don't think so. ^^^

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These users thanked the author Chris Pile for the post (total 2): joshnothing (Tue May 10, 2022 6:46 am) • Hesh (Tue May 10, 2022 2:46 am)
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PostPosted: Tue May 10, 2022 2:56 am 
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Old Growth Brazilian Rosewood
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There is a term in our business called "scope creep" where the scope AND budget of the project expand out of control. We cannot be spending 6 hours on some epoxy bridge reglue on a beater guitar or your business location will have a "vacancy" sign out front by the end of the year.

As it is.... to properly remove a bridge, prepare the bridge patch, prepare the bridge bottom, fit the bridge so that minimal clamping is required to have it fully seated everywhere and then to glue it on with the correct glue for the job and specific guitar we are hard pressed to do this so that the economics are there for more inexpensive instruments. Any mistakes, finish repairs or anything expanding the project and you just not only lost money but you have an "opportunity cost" of the other jobs you can't be doing while you **** around with this one.

I'm never going to advocate poor workmanship or rushing but I am going to advocate that Luthiers have to know when to call it good or when to walk away or not even accept the project in the first place. It's my belief AND experience that the single most common reason that Lutherie businesses fail is they attempt to be all things to all folks.

Can't remember who above said it is what it is but it is what it is :) and I would move on.

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These users thanked the author Hesh for the post: joshnothing (Tue May 10, 2022 6:47 am)
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PostPosted: Tue May 10, 2022 11:47 am 
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Brazilian Rosewood
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Lightly sand the epoxy -then dye it black.


Mike

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PostPosted: Wed May 18, 2022 10:11 am 
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Walnut
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JuanP if its any consolation your pics could be of the exact issue I have just had with an old Onyx guitar. I had not heard of the brand before but it looked like a copy of the old Ovation semi accoustics. Looked loke a fibreglass body with plastic/wood laminated top which is why I used epoxy to reglue the bridge. I thought I'd done a reasonable job cleaning up but still looks like yours. I re store rescue guitars and give them away so recipient was happy but I would have been in trouble if I did this for a living. Anyway lesson learned.



These users thanked the author David Herring for the post: Hesh (Thu May 19, 2022 3:00 am)
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PostPosted: Thu May 19, 2022 3:01 am 
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Old Growth Brazilian Rosewood
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David Herring wrote:
JuanP if its any consolation your pics could be of the exact issue I have just had with an old Onyx guitar. I had not heard of the brand before but it looked like a copy of the old Ovation semi accoustics. Looked loke a fibreglass body with plastic/wood laminated top which is why I used epoxy to reglue the bridge. I thought I'd done a reasonable job cleaning up but still looks like yours. I re store rescue guitars and give them away so recipient was happy but I would have been in trouble if I did this for a living. Anyway lesson learned.


David thanks for your efforts and service for less fortunate people. We accept beater guitars and repurpose for homeless and vets too.

I wanted to thank you for your efforts and welcome you to the forum. If I can ever help you with a guitar that you are fixing to give to someone please let me know, I'm happy to help.

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