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Old 02-21-2017, 09:30 PM
George Henry George Henry is offline
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Default Super glued bridges

I worked in QC and set up for a manufacturer whose guitars were mostly made in China. After experiencing an increase in bridge lift problems, I learned that the bridges had been super glued on. The process consisted of routing a cavity through the poly finish, applying super glue, and clamping the bridge down. It appeared that there was poor wood to wood contact and the expectation was that the glue would fill the gap. I was told that the whole production process required this method (time constraints) and that "all Pac-Rim manufacturers used super glue techniques.

Is this practice universal among PacRim manufacturers? What is the usual procedure for repairing lifting bridges on these super glued bridges? I have reglued an Eastman bridge, and did not witness a routed cavity, and the repair went normally.
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Old 02-21-2017, 09:36 PM
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fazool fazool is offline
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... I was told that the whole production process required this method (time constraints) and that "all Pac-Rim manufacturers used super glue techniques.....
That's a gigantic statement for someone to make, considering it covers about 2 billion people.

It's an even bigger statement to absorb without immediate rejection.
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Old 02-21-2017, 09:45 PM
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I have reglued an Eastman bridge, and did not witness a routed cavity, and the repair went normally.
Did you use CA?
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Old 02-21-2017, 09:58 PM
redir redir is offline
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I would not be at all surprised if CA was commonly used on cheaper factory guitars. I would however be surprised if they actually routed a footprint in the poly finish even in an attempt to reach bare wood. Typically you see bridge failures on cheap guitars where the bridge is glued right to the finish. Having said that a bridge glued to a poly finish with CA if done properly imho would probably be suitable.

To repair guitars like that I scrape down to bare wood on both the guitar top and the bridge and use Titebond.
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Old 02-21-2017, 10:07 PM
Arumako Arumako is offline
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Originally Posted by George Henry View Post
Is this practice universal among PacRim manufacturers? What is the usual procedure for repairing lifting bridges on these super glued bridges? I have reglued an Eastman bridge, and did not witness a routed cavity, and the repair went normally.
No. I live in Asia (Japan). I've taken apart many so called PacRim assembled guitars MIJs, MIKs, MICs, Indonesia and others etc. Not one of them used CA. A variety of epoxy resin adhesives for sure, hide glue, a variety of unusual wood glues, fish glues, some really interesting un-identifiable local stuff, but never CA.

Personally, I would never use CA for a bridge assembly. Prefer hide glue or epoxies...some Japanese wood glues are excellent.
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Old 02-22-2017, 06:37 AM
LouieAtienza LouieAtienza is offline
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Actually, CA stick pretty tenaciously to poly, so they wouldn't even really need to route a cavity, unless they're also doing it for bridge placement/glue abatement.
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Old 02-22-2017, 07:03 AM
mirwa mirwa is offline
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I personally would not use super glue to hold a bridge down, but rosewood loves superglue, so it does not surprise me if someone superglues a rosewood bridge to a poly top.

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Old 02-22-2017, 07:11 AM
B. Howard B. Howard is offline
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Most of them I see just had the bridge CA'd to the poly finish after a bit of roughing up the gloss surface.

This is actually pretty high class considering I saw a Chinese made twelve string some time back that was constructed entirely with hot glue.......
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Old 02-22-2017, 07:37 AM
Hot Vibrato Hot Vibrato is offline
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I just did a bridge reglue on a Chinese Guild, and the bridge had been attached with CA.

CA wouldn't be my choice for gluing a bridge, but I imagine that if the surfaces were properly prepped, it would hold really well. But of course doing the job properly defeats the purpose of using CA, which is obviously chosen for its gap filling properties. The reason this Guild bridge came off, and the reason any other bridge ever comes off, is because of poor surface preparation. If you achieve wood-to-wood contact, the bridge will never pull loose unless it's subjected to extreme heat. Proper surface preparation is far more important than one's choice of glue.
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Old 02-22-2017, 09:13 AM
George Henry George Henry is offline
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The bridges were definitely glued directly onto a cavity which was both too small and too deep. I repaired two myself which I had purchased. The issue became so problematic for the company that often over 50% of shipments had bridge lifts. We checked every guitar for bridge lifts by probing with extra thin feeler gauges. We got quite good at it. Needless to say, the issue didn't help guitar sales.

The two guitars I repaired were all solid builds with list prices over $1,000. I repaired them by cleaning the cavities and regluing with slow drying clear epoxy. I was looking for something both effective and clean looking. My solution did not follow orthodox repair techniques, but it worked. The original build technique was not orthodox either.

Last edited by George Henry; 02-22-2017 at 01:03 PM.
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Old 09-07-2019, 07:30 AM
Arumako Arumako is offline
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Quote:
Originally Posted by Arumako View Post
No. I live in Asia (Japan). I've taken apart many so called PacRim assembled guitars MIJs, MIKs, MICs, Indonesia and others etc. Not one of them used CA. A variety of epoxy resin adhesives for sure, hide glue, a variety of unusual wood glues, fish glues, some really interesting un-identifiable local stuff, but never CA.
Hi George Henry,
It's been a long time since my last visit here at AGF, and as I was reviewing my posts, I came across this one! Yikes, my comment was obviously out of my own ignorance. Since that post, I've had to work on several guitars that used CA for bridge installations. As noted in some of the responses CA works well with poly finishes and rosewood bridges, AND apparently often used on lower budget pac-rim guitars. Apologize for the misleading comment! However, still gotta say CA is not the way to go. Rosewood and poly make a strong bond, but the poly paint can "lift" from the top wood and the string tension can tear the bridge away from the top with the finish and bridge intact. Better to have wood to wood adhesion for a high stress joint, I think...
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Old 09-07-2019, 09:33 AM
geelinus geelinus is offline
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Quote:
Originally Posted by fazool View Post
That's a gigantic statement for someone to make, considering it covers about 2 billion people..
The entire Chinese population builds guitars? 😊
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