Neck issues.. what would you do?

[mr.mow]

So I bought a bass from a guy.. 62RI Jazz..
It arrived neck and body separately to save on shipping.

Now, when I assembled it the action was a mile high.. fine.. so tried adjusting the truss rod cos there was huge neck relief.. truss wouldn't tighten (happy to loosen though..) This is the neck with no load on it..




So, I went the back clamp idea, managed to fit 4X1mm washers in there (still room for another one ), if I clamp the BUGGERY out of it and reaaaaaally tighten the truss I can get a nice back bow happening (I'm REALLY cranking the clamp down hard, to the point of oh **** im gonna break it).

But within days the neck starts rising again..

what would you do?

[JLS]

"what would you do?"


That neck needs to get a heat treatment, and/or replaning/refretting. Or, return it, if you can--that's one F'd up neck!

[mr.mow]

Originally Posted by JLS

"what would you do?"


That neck needs to get a heat treatment, and/or replaning/refretting. Or, return it, if you can--that's one F'd up neck!

Does this mean the back clamping I did is not a long term solution?

What may have caused this kind of bending of the neck?

[Jim C]

Assuming that table is truly flat, that neck is way bent
I beleive that many times lumber will have a memory and that the heat / press will be a temporary solution (for a major re-shape) that will not stay put over the long run
.02

[JLS]

Originally Posted by mr.mow

Does this mean the back clamping I did is not a long term solution?

What may have caused this kind of bending of the neck?

If backclamping didn't work, then it's not a solution at all.

This is often caused by someone going years between setups, and the neck taking a forward "set". I've never had a heatpressed neck go back, though I've heard that Martin acoustics w/o adjustable trussrods, will do that.

[251]

Originally Posted by mr.mow

So I bought a bass from a guy.. 62RI Jazz..
It arrived neck and body separately to save on shipping.

Now, when I assembled it the action was a mile high.. fine.. so tried adjusting the truss rod cos there was huge neck relief.. truss wouldn't tighten (happy to loosen though..) This is the neck with no load on it..




So, I went the back clamp idea, managed to fit 4X1mm washers in there (still room for another one ), if I clamp the BUGGERY out of it and reaaaaaally tighten the truss I can get a nice back bow happening (I'm REALLY cranking the clamp down hard, to the point of oh **** im gonna break it).

But within days the neck starts rising again..

what would you do?

I believe the fret board material has shrunk, considerably. It most likely was not seasoned in the shop before the neck was assembled. It clearly is not a good match for the neck material. I doubt the cost of a new fret board is justified but I have never priced one. Perhaps a new neck? Sad to see such thoughtless craftsmanship. 8-(

[Labi]

Originally Posted by mr.mow

Does this mean the back clamping I did is not a long term solution?

Well is it?

Originally Posted by mr.mow

But within days the neck starts rising again..

[251]

Originally Posted by Labi

Well is it?

I regret to say, it would surprise me to hear you could fix this with steam &/or clamps.

[mr.mow]

For anyone who cares.. It's a 2009 fender American vintage 62 jazz..

[Jim C]

Originally Posted by 251

I believe the fret board material has shrunk, considerably. It most likely was not seasoned in the shop before the neck was assembled. It clearly is not a good match for the neck material. 8-(

Can a 1/4 fret board make a thick piece of maple with a steel truss rod bow that much?

[JLS]

Originally Posted by 251

I regret to say, it would surprise me to hear you could fix this with steam &/or clamps.

Steam is not used for this operation. I have a neck heater, others use heat blankets or heatlamps. It would certainly work for the neck in the above photograph.

[JLS]

Originally Posted by 251

I believe the fret board material has shrunk, considerably. It most likely was not seasoned in the shop before the neck was assembled. It clearly is not a good match for the neck material. I doubt the cost of a new fret board is justified but I have never priced one. Perhaps a new neck? Sad to see such thoughtless craftsmanship. 8-(

I doubt this.When fingerboards shrink, they shrink in width, not length. This bass was too long untended to, and the neck took a bow, and stayed there.

[251]

Differential shrinkage is important. Here is a mistake I made cross laminating well seasoned Walnut & Maple scraps. Note; the the glue line is stronger than the Maple. The resulting force can be impressive & predicting the outcome takes thought & experience, which I clearly lacked making the lid for this box. Likewise the person who supervised the worker who made the neck being discussed.

I'll stick with my original assertion, the Rosewood has shrunk more than the Maple & no amount of heat, clamping force or steam will permanently stretch the Rosewood to straighten that neck. Regrets to the OP. 8-)

[JLS]

Originally Posted by 251

Differential shrinkage is important. Here is a mistake I made cross laminating well seasoned Walnut & Maple scraps. Note; the the glue line is stronger than the Maple. The resulting force can be impressive & predicting the outcome takes thought & experience, which I clearly lacked making the lid for this box. Likewise the person who supervised the worker who made the neck being discussed.

I'll stick with my original assertion, the Rosewood has shrunk more than the Maple & no amount of heat, clamping force or steam will permanently stretch the Rosewood to straighten that neck. Regrets to the OP. 8-)

The fingerboard isn't "cross laminated" to the neckshaft.

[vejesse]

JLS is right on here regarding how wood moves. Here's what probably happened: someone left this bass at string tension in a hot car and the glue in the neck/fingerboard joint crept. Then he realized what happened and unloaded the bass.

[251]

Originally Posted by JLS

The fingerboard isn't "cross laminated" to the neckshaft.

The photo is there to illustrate the amount of force that can develop & the strength of a glue bond.

In this case, the force is acting along the axis of the neck, shortening the side with the frets. Do you see how shrinking the fret board will put a permanent bow in the neck?

[vejesse]

I'll qualify my statement: a lot depends on which way the grain runs in the neck and fingerboard. If you have slab cut wood you should look at orienting the grain to counteract wood movement. If necks were always vertically quartersawn things would be more predictable. Maybe in this case you have two pieces of wood warping the same way with an additive effect. I still say it's likely someone left it in a hot car.