Bridge screws

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Fernando Esteves
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Bridge screws

Post by Fernando Esteves »

Hello!
One more newbie question:
I saw that some builders screw the bridge on acoustic guitars and some others seems to not glue.
What is the deal with screwing? The glue can't handle the bridge with the strings tension?
I tend to think that no screws is better than screws...
Amateur luthier from Brazil.
I'm here to learn!!!
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Barry Daniels
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Re: Bridge screws

Post by Barry Daniels »

No individual builder would use screws on a bridge. Screws are normally a sign of a cheap and poorly built factory instrument. A well prepared gluing surface and good glue are more than up to the job.
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Alan Carruth
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Re: Bridge screws

Post by Alan Carruth »

I'd go further and say that screws end up making the joint WORSE. They concentrate the stress, so that WHEN the glue lets go (it always does) you get more distortion which makes it a lot harder to replace the bridge. In the worst case the screws rip out pieces of the top. Back when I did more repairs I hated to see guitars with screws anyplace, but the bridge was just about the worst. They can make an easy fix just about impossible.
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Fernando Esteves
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Re: Bridge screws

Post by Fernando Esteves »

Cool! Screws out! :)
Amateur luthier from Brazil.
I'm here to learn!!!
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Barry Daniels
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Re: Bridge screws

Post by Barry Daniels »

Alan, I agree with you, but I was trying not to insult screws or hardware in general. We have to be PC, you know.
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Mike Ryan
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Re: Bridge screws

Post by Mike Ryan »

I did a loose bridge repair on a famous maker guitar bought for about $800. It had screws and squiggly blue like epoxy on top of the finish. After I scraped through the finish, I glued the bridge on and that guitar sounded a lot better. BUT, the guitar was Pretty.
Mike Ryan
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Re: Bridge screws

Post by Mike Ryan »

that's glue not blue.
David Boehnker
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Re: Bridge screws

Post by David Boehnker »

I have a 1969 Bozo Podunavac jumbo guitar - the bridge has two thin bolts through it with nuts under the spruce bridge plate. Two pearl inlays over the bolts, and it looks original (I've had it since 1977). Sounds great.
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Peter Wilcox
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Re: Bridge screws

Post by Peter Wilcox »

Recently I repaired a poorly engineered $400 guitar that had fallen over and the neck broke loose at the heel. It was a glued butt joint with a single 1/4" wooden dowel, presumably for positioning for assembly. After I reglued it, I noticed it had a buzz, most noticeable when playing the A string with the guitar horizontal on my lap. The buzz pretty much disappeared in playing position. I checked all the usual suspects without success, and finally decided to see if one of the ball ends was loose, and possibly change the A string. When I reached into the sound hole, I felt something unusual near the bridge pins.

Turns out the bridge was fastened on with 2 machine screws, the heads hidden under round plastic inserts from the outside, and one of the nuts had loosened and was buzzing on the screw. Live and learn.

In my own experience, screws are superfluous for a pinned bridge. The bridge will stay on even without being glued, just from the mechanics of the assembly.
Maybe I can't fix it, but I can fix it so no one can fix it
Clay Schaeffer
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Re: Bridge screws

Post by Clay Schaeffer »

Some "pinless" bridge designs use string posts that essentially function as mechanical fasteners to help resist the pull of the strings. To reduce the size of the bridge footprint small bolts if properly located and anchored may be desirable. Typically bolted bridges place the bolts on the wings of the bridge where they do the least good and often fail. I think bolting closer to the string works better.
Alan Carruth
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Re: Bridge screws

Post by Alan Carruth »

Having seen a number of bolted and pinned bridge designs, I'd say that IMO it's NEVER an improvement. Some designs may be less detrimental than others, but they're not 'better'.
Clay Schaeffer
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Re: Bridge screws

Post by Clay Schaeffer »

Alan,
You don't feel Doolin's metal pins which anchor the ball ends of the string and essentially "pin " the pinless bridge add any strength to the design?
Alan Carruth
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Re: Bridge screws

Post by Alan Carruth »

I use that design, which was, iirc, first devised by Elliot or Sullivan, and used on John Doan's harp guitar. I don't put the pins through into the top, and so far it has worked very well. At any rate, the little pins are not there to take the string tension, which is conveyed to the bridge by the ball end hitting the side of the hole. The pins just keep the ball from flipping sideways and getting loose that way.
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