Garrison 12 string Buzz.

[Tom Sommerville]

I've been doing repairs on a Garrison 12 string
-- they were bought out by Gibson some time back. They were noted for their molded fiber-glass or carbon-fiber skeleton and for using alternative woods; on this model I think red birch is used for both body and neck. The top is Western Cedar.

Their fondness for molded fiber reinforcement doesn't seem to have been carried over to the neck; as far as I can tell, the only reinforcement there seems to be a single truss-rod with a nut sized to fit a 3/16" inch rod.

It has a nasty buzz on the A string from the 3rd to the 7th fret.

I've tweaked this thing every way I can think of-- rocked the frets, tightened and loosened the nut, leveled the frets, glued them with thin superglue, installed nuts and saddles with wider spacing between courses. I've changed strings and increased the tension. I've rapped the body and found no rattles. The pins don't seem loose and are relatively soft plastic.

I'm wondering if it's that the neck, though strong, is not stiff enough.
It seems rubbery, actually. Has anyone had an experience with necks oscillating enough to cause such a problem?

[Kerry Krishna]

 Tom, I know this from painful experience: It may be time to bite the bullet, curb your pride, and take it to another Luthier. I have had to do this exact thing several times in my life, and it is always a terrific bonding experience.

 It has NOT always ended with actual results though. Good luck resolving this... 

[Mike Kolb]

Those elusive buzzes can be nasty. Have you checked that the truss rod itself might not be the culprit?  And, of course, there's Frank's "Big Buzz List"... it's a good checklist to run-through.

http://www.frets.com/FretsPages/Luthier/Technique/Setup/BuzzDiagnos...

[Tom Sommerville]

Thanks for your replies.

I haven't done anything yet, but remove the strings.

Question: how low can frets go before you need a refret?

Right now the frets are around .031. I figured I could get by with that, but now...

[Keith Hustler]

Hi Tom. You said you rocked the frets. Have level the frets yet?

[Keith Hustler]

Sorry. I see in your comments you did level the frets. I have had a couple guitars with inconsistent neck density. They do not bend in a fair curve under string tension. When get the thing up to pitch , the neck may have a flat section in the curve.

[Tom Sommerville]

Hi Keith,

"They do not bend in a fair curve under string tension."

Very well put.

The neck get's pretty chunky at the heel and that thought had crossed my mind. I wonder if  the situation could be remedied by profiling the back of the neck.

I can say this much: from now on I'm paying particular to this when carving my own necks. I guess that's the benefit of this frustration.

[Paul Verticchio]

Instead of addressing the neck's back profile, I'd pull the frets and level the FB in relation to the geometry of the bridge. A refret, level & re-crown/polish should take care of your problems. The low height of the existing frets, in my opinion and for my own requirements, is too low. But, that's a matter of personal preference.

The late great guitar company, Hamer, used to build the guitar up to the point it would be fretted (with the neck attached to the body). They would then let the neck, FB  and body unit "de-stress" itself for 60 days. They would then level the FB in relation to the bridge. This would often result in a FB whose edges weren't parallel to the neck and it threw those not in the know. The result was guitars with unsurpassed playability and LONG TERM structural integrity. They had VERY few warranty claims citing twisted necks and wonky action.

As a personal note: I don't use the fret rocker. It doesn't allow one to perform the most important part of a re-fret: addressing the action as a 'system' in relation to the neck and bridge. I'm sure it has some sort of purpose, but I haven't found it. You can't deny that it looks cute on the bench. You can find it discussed in detail in the forum's archives. Especially read the comments by our friends Hesh Breakstone and Rusty Vance for the real deal explanation.

Best of luck with this guitar :)

[Ned Knepp]

I haven't used one so I may be in left field but I wonder of this is a job for one of Erlewine's neck jigs. I thought about how I would address a fretboard on a neck that doesn't bend evenly and realized that I couldn't do it with what I have available in my "tool box". It just seems like a problem needing to be addressed with the neck under string tension or, at lease in that shape/position.