Horizontally laminated neck, yes or no?

[pilotjones]

The point I was trying to make is, I think, illustrated by your examples. AFAIK, the relatively low stiffness - flexbility - of Kevlar can be an asset in boat hulls, bicycle frames, snow boards and skis. It has a high strength to weight, but a low stiffness to weight. And stiffness is the overriding concern in neck construction, as nearly any material normally used has more than enough strength; and in adding reinforcments such as CF bars, we are not actually trying to increase the strength, but rather the stiffness.

 

[T-Bird]

Hi.

At what point along the neck did these fingerboard separations take place?

From the nut, up to the 10th fret, usually only to 3rd or 5th though. Most of those problems have been on cheaper instruments and judging by the separation, the reason has been unsuitable glue. My guess is that the joints haven't been strong enough to withstand the 20 year or so climate change tension variations in the neck. That's the reason I suggested careful research on the glue if such a technique is to be used.

It usually gets at least -25 celsius in the winter and although only about +25 C during the summer here in Finland, the humidity changes quite a lot. And as the OP and I seem to share the same climate, I felt that the correct glue is an important thing to be considered.

One almost common thing among those examples I have seen have been rosewood FB glued to another species.

Regards
Sam

 

[pilotjones]

Hi.



From the nut, up to the 10th fret, usually only to 3rd or 5th though. Most of those problems have been on cheaper instruments and judging by the separation, the reason has been unsuitable glue. My guess is that the joints haven't been strong enough to withstand the 20 year or so climate change tension variations in the neck. That's the reason I suggested careful research on the glue if such a technique is to be used.

It usually gets at least -25 celsius in the winter and although only about +25 C during the summer here in Finland, the humidity changes quite a lot. And as the OP and I seem to share the same climate, I felt that the correct glue is an important thing to be considered.

One almost common thing among those examples I have seen have been rosewood FB glued to another species.

Regards
Sam

Thanks. The reason I was wondering is that glue failure could be caused by direct shear due to bending moment, or by direct tension due to truss rod action. Actually, it should be a combination of both, it's just a matter of which predominates.

If it had been at the middle of the neck and not the ends, it would have been a fairly clear case of truss rod pressure. But as you describe it, I cannot really attribute it either way.

 

[Taylor Livingston]

Out of curiosity, what would be the advantage of parallel laminates? It seems like there would be no point in doing something that is far less proven over time if there were no advantages. I guess maybe there would be less waste of wood, but what else?

 

[MPU]

I guess the same as any hippie sandwich. Looks mainly (if you happen to like the looks). But as we well know, there's no sense in making instruments in the first place. Shops are full of them already
Marko

 

[pilotjones]

Out of curiosity, what would be the advantage of parallel laminates? It seems like there would be no point in doing something that is far less proven over time if there were no advantages. I guess maybe there would be less waste of wood, but what else?

If you were to make a neck that was horizontally symmetrical--e.g. with the same woods, and the same finishes, for the fingerboard and the back layers, and a different core in between--it should in theory have little or no reaction to changes in temperature or humidity, as any induced bending forces would cancel out.

People wouldn't dream of making a neck with vertical laminations, that wasn't symmetrical about the vertical plane, because they know it will bend sideways with ambient changes. But they give no thought whatever to putting a rosewoood board on a maple shaft, as movement forward and back is simply accepted, and compensated for with truss adjustments.

 

[Taylor Livingston]

If you were to make a neck that was horizontally symmetrical--e.g. with the same woods, and the same finishes, for the fingerboard and the back layers, and a different core in between--it should in theory have little or no reaction to changes in temperature or humidity, as any induced bending forces would cancel out.

People wouldn't dream of making a neck with vertical laminations, that wasn't symmetrical about the vertical plane, because they know it will bend sideways with ambient changes. But they give no thought whatever to putting a rosewoood board on a maple shaft, as movement forward and back is simply accepted, and compensated for with truss adjustments.

Well, I've put thought into that, which is why I've spec'ed a wenge fingerboard and wenge neck on any custom I've spec'ed out (so far I've only had one made). I wonder if any people with JP basses could comment on the stability of their necks and whether they've noticed any separation. His instruments are not old enough to give a long term picture, but it would be interesting to see.

 

[pilotjones]

Linc Luthier has been doing them for a while.