Straightening A Bowed Bass Neck: Help!

[slor]

Here's my problem of the week: I have on the bench a fairly well-beaten Fender P-Bass neck, looks to be early-70s vintage. Even with the truss rod good and tight, the neck has a healthy upbow. Even after inserting a washer into the truss rod cavity behind the nut, and clamping the neck into backbow before tightening the rod, the best I can get is a somewhat flat neck. I imagine that will change under string tension. Any other ideas?

Thanks,

Seth

[killemall8]

Here's my problem of the week: I have on the bench a fairly well-beaten Fender P-Bass neck, looks to be early-70s vintage. Even with the truss rod good and tight, the neck has a healthy upbow. Even after inserting a washer into the truss rod cavity behind the nut, and clamping the neck into backbow before tightening the rod, the best I can get is a somewhat flat neck. I imagine that will change under string tension. Any other ideas?

Thanks,

Seth

most bass necks are supposed to have a up bow, becuase when you string it up the tension of the strings will even it out

[Mattia]

Here's my problem of the week: I have on the bench a fairly well-beaten Fender P-Bass neck, looks to be early-70s vintage. Even with the truss rod good and tight, the neck has a healthy upbow. Even after inserting a washer into the truss rod cavity behind the nut, and clamping the neck into backbow before tightening the rod, the best I can get is a somewhat flat neck. I imagine that will change under string tension. Any other ideas?

Thanks,

Seth

most bass necks are supposed to have a up bow, becuase when you string it up the tension of the strings will even it out

Uh, no, they're not. Upbow = bow in the direction the strings pull.

Necks should be flat, or have a tiny amount of upbow and be absurdly stiff. Or a tiny bit of backbow and be a little on the floppy side.

Have you tried clamping it straight and then adjusting the rod? Otherwise a bit of heat+clamp action might help. Check Frets.com, I'd be surprised if Frank Ford hasn't written something on straightening necks.

[killemall8]

Here's my problem of the week: I have on the bench a fairly well-beaten Fender P-Bass neck, looks to be early-70s vintage. Even with the truss rod good and tight, the neck has a healthy upbow. Even after inserting a washer into the truss rod cavity behind the nut, and clamping the neck into backbow before tightening the rod, the best I can get is a somewhat flat neck. I imagine that will change under string tension. Any other ideas?

Thanks,

Seth

most bass necks are supposed to have a up bow, becuase when you string it up the tension of the strings will even it out

Uh, no, they're not. Upbow = bow in the direction the strings pull.

Necks should be flat, or have a tiny amount of upbow and be absurdly stiff. Or a tiny bit of backbow and be a little on the floppy side.

Have you tried clamping it straight and then adjusting the rod? Otherwise a bit of heat+clamp action might help. Check Frets.com, I'd be surprised if Frank Ford hasn't written something on straightening necks.

well the 2 basses that i painted were like that. when i took the necks off, they would get back bow, and when i strung them up again it would go away from the tension of the strings.

[Mattia]

Methinks you're not reading the original post: "Even with the truss rod good and tight, the neck has a healthy upbow"

He doesn't have backbow. That would (potentially) be less of a problem.

(note that I'm not reading the original post fully either, as he's already tried what I suggested to no avail, at least the first bit, but we're ignoring that.)

[slor]

Methinks you're not reading the original post: "Even with the truss rod good and tight, the neck has a healthy upbow"

He doesn't have backbow. That would (potentially) be less of a problem.

(note that I'm not reading the original post fully either, as he's already tried what I suggested to no avail, at least the first bit, but we're ignoring that.)

Indeed. But I appreciate the help nonetheless. I strung the bass up today as-is and relief is close to .03. At this point I'm thinking the fretboard is going to have to come off. I'm not sure how to diagnose a broken truss rod (other than an extremely obvious deformation or break). But I don't believe conventional techniques are going to help in this case. Thanks again people!

-Seth

[Mattia]

A bent neck usually isn't a sign of a broken truss rod, but of the wood moving despite the truss rod being in there!

Before doing anything so drastic as removing the fretboard, check Frets.com and register at MIMF.com and look up threads on dealing with warped/bent necks. Usually, heat lamps (slip the glue joint between fingerboard and neck a little, let it creep) and some judicious clamping can fix this sort of thing, especially if it's not really twisted, and just bowed.