Bridge Splitting on JF30-12

[Dr Izza Plumber]

The bridge is beginning to split on My JF30-12, and I was thinking about changing the saddle, and fitting a compensated tusk saddle to the bridge.
The split originates from the 12th pin on the lower set, straight through the bridge to the first pin.

I've never had a wood bridge crack on any guitar before, so I'm not sure if I should replace the saddle, or glue it, and/or with what glue?

The pins are bone replacements, and they easily fit into the bridge with very little sanding (to only a few of the 12 pins), though I suppose that it's possible the wood shrunk, or the bone expanded with humidity.

I'd appreciate Your input, and I do have a local luthier, though I believe that moi can handle this task, if properly instructed.

Too bad Don is so far away, and I'm one who hates shipping guitars and guns because of the rough handling practices, and insurance pirates who deny claims.

Here's an image to view:

 

[killdeer43]

You might try applying Hide Glue, available in fine hardware stores from coast to coast. :wink:

Joe

 

[jazzmang]

The permanent, proper (and of course, more expensive) fix would be to have the bridge fully replaced.

My local luthier charges about $300 for all.

 

[Dr Izza Plumber]

I've got the pins out at the moment, and they were not at all tight, a near perfect fit, though the split is noticeable, devoid of pins and strings.

I'll look for a new Guild bridge, and perhaps I can find one for the 1/8" saddle, so I won't have to spend an entire afternoon sanding & fitting.

 

[Nigel Wickwire]

Are the strings in the back row (toward the end block) supposed to be touching the bridge pins in the front row?

I would think that would apply some lateral force to the pin holes. The twelvers I've been around, the strings in the back row have a straight shot to the saddle, NOT bent around bridge pins in the front row. I'd suggest the bridge was drilled incorrectly or the bridge pins aren't the right ones for this application. Just my $.02. Perhaps someone with more knowledge can jump in here and straighten me out.

~nw

 

[wontox]

My two cents worth, I'd work some dark-colored aliphatic resin glue (Elmers-type, available in dark colors for stained wood projects) into the crack, wipe clean with a damp cloth and see if that doesn't fix it, which I think it should. You might even insert an exacto blade to slightly temporarily widen the crack to accomodate the glue. If it doesn't work to your satisfaction, you can always go the bridge replacement route and have created no harm with an easy glue fix.

Wontox

 

[Dr Izza Plumber]

Are the strings in the back row (toward the end block) supposed to be touching the bridge pins in the front row?

I would think that would apply some lateral force to the pin holes. The twelvers I've been around, the strings in the back row have a straight shot to the saddle, NOT bent around bridge pins in the front row. I'd suggest the bridge was drilled incorrectly or the bridge pins aren't the right ones for this application. Just my $.02. Perhaps someone with more knowledge can jump in here and straighten me out.

~nw

TY, I noticed that in My posted image.

Probably My fault for not fitting the strings exactly into the pin recesses, after I R&R'd the saddle to measure for replacement blanks.

I have difficulty with close up vision some days, even when wearing My prescription reading glasses.

 

[chazmo]

Doc,

Is your guitar too dry or wet? While yours looks very minor, I'm a little concerned about the geometry of the top that would cause the bridge to split at all (sometimes from too much belly).

Fixing it is really no biggie, but you might need to flatten out the top a little and maybe some of the bracing needs re-gluing. Given the hairline nature of yours, probably just a little filler will do just fine. Again, just make sure the guitar is stablized in correct humidity and isn't exhibiting significant belly (or caving in).

 

[12stringer]

With the pins out, use a magnifying glass and a good strong light and looking into the pin holes, see if you can tell how deep the crack is....if it is all the way down, then bridge replacement is the way to go...if it is shallow you could fill with glue and monitor it over time.


You could also use your digital camera and take a few pictures and blow them up for a close look at the crack.

Just my .02 cents....best of luck

 

[Dr Izza Plumber]

I'll take a closer look, but I want the local luthier to take a look-see because He actually builds and repairs instruments for a living, and I do not.

Thank You for the continuing input, I knew that I'd be well advised here.

 

[Dr Izza Plumber]

Doc,

Is your guitar too dry or wet? While yours looks very minor, I'm a little concerned about the geometry of the top that would cause the bridge to split at all (sometimes from too much belly).

Fixing it is really no biggie, but you might need to flatten out the top a little and maybe some of the bracing needs re-gluing. Given the hairline nature of yours, probably just a little filler will do just fine. Again, just make sure the guitar is stablized in correct humidity and isn't exhibiting significant belly (or caving in).

Chaz,

I reached inside and the bracing seems secure.

FWIW: when I push up gently on the top under the bridge, the split opens slightly, so We obviously need to have those braces looked at.
I have light D'Addario coated strings on it, but I generally use concert pitch for tuning.
From hereon, she'll be tuned down one step.

With the pins out, use a magnifying glass and a good strong light and looking into the pin holes, see if you can tell how deep the crack is....if it is all the way down, then bridge replacement is the way to go...if it is shallow you could fill with glue and monitor it over time.
You could also use your digital camera and take a few pictures and blow them up for a close look at the crack.
Just my .02 cents....best of luck

The split seems involved from the bottom, upward.

 

[taabru45]

If it comes to bridge replacement, I think Hans has a few originals in his possession, first place to look. then of course the Guild factory. Steffan

 

[Dr Izza Plumber]

If it comes to bridge replacement, I think Hans has a few originals in his possession, first place to look. then of course the Guild factory. Steffan

Thanks! I will contact Hans if the Luthier says to replace.

 

[GardMan]

I don't know enough to know how the offset string angles could cause the crack you've got...

The bridge on my D-50 had a hairline split between the bridge pins when I bought it... first, I checked inside (before buying) to make sure there weren't any other major issues (like a splitting or damaged bridge plate).

I queried the folks over at frets.net, Frank Ford's luthier bulletin board, and the consensus was to wick in some thin super glue, perhaps blowing/sprinkling some ebony dust into the glue before it sets. Then finish with some fine grit sandpaper.

So I bought some "water thin" superglue from StewMac, along with an ebony violin pin to use as a source of ebony dust.Took me a month to work up the courage, but I pulled the strings off, masked evrything except the area of the bridge I was working on, and used a micropipet from my lab to run a thin line (~ 10 microliters) of superglue along the crack... most of which wicked into the crack. I blew in some ebony dust, let it cure 30', then repeated with a little more glue and dust. I also ran a tiny amount of glue along the insides of the pin holes where the crack extended into the wood (I couldn't see the crack)... to try and get glue well into the crack. After a little sanding with 400 and then 800 grit sandpaper to remove the excess glue and dust, the repair is essentially invisible... and has held now for a year. Cost me <$15.

 

[jazzmang]

Also, if you contact FMIC consumer relations, they may be able to provide you with a part number for a new Guild 12-string bridge, although I'm not sure the new bridges have the same dimensions as the old ones... (you'd definitely have to have a new saddle cut, as the new ones are almost twice as thick!)

Its worth a shot to check in case Hans doesn't have one.

 

[killdeer43]

To reiterate....

http://woodworker.com/fullpres.asp?PARTNUM=872-203&LARGEVIEW=ON

This stuff works. You can force it into the crack, wipe off the residue and set it aside.
If the crack isn't all the way through the bridge, you should be OK. :wink:

Joe

 

[curt]

Is the bridge ebony? Ebony splits like that all the time and usually the cracks don't get bigger.

Using glue other than epoxy as a 'filler' is a waste of time and wouldn't help at all. If it were my guitar and if I decided to mend the crack I would mix up some West System epoxy and while the bridge is under load drop some glue in the crack. As the wood absorbs the glue continue to add more over twenty minutes. Get some cotton cloths ready and then remove the string tension along with the squeeze out. Let it cure for 12 hours at room temperature, tune and play it for the next 50 years.

EDIT: as far as choice of glue it's always important to consider the repair location so you won't preclude and further work. So you don't want to epoxy a neck in unless you have to due to repair but almost always use it on a headstock repair for its superior strength.

Even another EDIT: Looking at the picture again, if it were mine I wouldn't worry about that crack. It's not going to get any longer because the holes have isolated it.

For credibility I've attached a link to a few of the guitars I've worked on.

http://www.midstateguitars.com/guitarsintheshop.html

 

[killdeer43]

For credibility I've attached a link to a few of the guitars I've worked on.

http://www.midstateguitars.com/guitarsintheshop.html

You're entirely credible. Nice work, indeed! :wink:

Cheers,
Joe

 

[Dr Izza Plumber]

Thank You, Curt!

Hans confirmed the bridge is ebony, and He doesn't have that particular bridge available, though He did say building a copy of the bridge is possible.

I'm going to see the Luthier as soon as I can phone him, and I'd bet that He will repair the bridge as You have indicated.

 

[Russell Letson]

Definitely ask a trusted repairman for advice--that's where the experience builds up.

When my D-40 developed cracks through the pin holes, my repair guy opted not to replace the whole bridge but to dowel the holes completely closed. He then routed out a rectangular area around the old holes, glued in a new piece of ebony, and re-drilled the holes. That was nearly 20 years ago. He also filled in the slot for the original through saddle and reslotted to accept an enclosed saddle that would take a Baggs ribbon pickup for a Dual Source system. It has held up quite well.

Of course, a 12-string has different geometry and stresses, and the cracks in the photo aren't nearly as bad as mine were, so the glue-and-ebony-dust approach might be sufficient. But I'd certainly have an experienced repairman make the call.