Adding a reinforcement to a neck...

[Beate Ritzert]

The problem might be a bit exotic: i would like to add a wooden reinforcement to an old neck. Like that:



My main goal is to thicken the neck - when i built it i needed to make it about 1.5-2 mm flatter than i wanted in order to compensate for a mistake. So it came out a bit too thin for my hands, and recently it starts to become uncomfortable as my hands do regularly hurt from my work. The above photo show an arrangement to test my idea.

What i want is o add a stripe of Machiche to the back - a rest of the piece of wood i've been using as the reinforcement of that neck. (It has no adjustable truss rod but is just constructed for stiffness.)
I also want to let it run slightly oblique along the length in order to optimize the neck for a good position of my left hand.

My problem here is that i do not know how i'd best deal with that stripe at the heel and at the headstock. In other words: it a stripe between the two rounded surfaces.



I would of course like to have a smooth transition, and i would like to try to remove as little wood as possible from the neck, and if ever possible try to increase the strength of the headstock joint. That is a bit weak because i was using inappropriate glue. That is also one of the reasons why i do not want to touch the fingerboard - i am happy that my repair holds and won't touch that spot again.

Therefore any tips welcome.

[Barry Daniels]

I wouldn't add a bumpy strip like that. If I had to do this, I would flatten the back of the neck, glue on a wider board and then blend it into a smooth shape so the neck looks and feels normal.

[Mario Proulx]

You won't like what I'm about to write....

It will be simpler, faster, and much, much better to simply bite the bullet and make a new neck.

[Brian Evans]

At the risk (nay, the fact) of being redundant - what Barry said, then what Mario said...

Brian

[Beate Ritzert]

You won't like what I'm about to write....

It will be simpler, faster, and much, much better to simply bite the bullet and make a new neck.

It is a neck through bass...

[Mario Proulx]

Ouch....

Well, you could cut it off, rout a neck pocket and bolt-in a new neck...

[Beate Ritzert]

Well, before i cut my beloved bass into pieces, i'll try make the change reversible....

I carefully cleaned and prepared the surfaces and try to glue that with HHG, so the stripe can be taken off again if needed. Thanks its flat profile almost no material had to be taken off the neck.
The stripe will be slightly offset in order to give best support for the thumb, if i'm successful i'll just need to close a very narrow gap at the headstock side with a bit of varnish...

[David King]

There is actually very little strain from string tension at the nut end of the neck. The volute is mostly there to reinforce in case the instrument falls over and lands on the headstock. The heel is a different story because that's where most of the stress will be. I'd rout a slot 10-20 cm into the back of the heel.

[Beate Ritzert]

Mhmm, in this case there is a large angle of the strings over the nut. Hence the strain at that point is large, at least, a lot larger than usual. But anyway - statically the neck is just perfect. Straight as 13 years ago when i built this bass.

Dynamically i noticed some issues after cutting the headstock to its present state - after that mod i suddenly had some feedback issues. Using heavier tuners seems to improve that a lot. And the heel is really strong and also well below the fingerboard.

But that's not the primary goal of my mod. It is really about getting to a better positioning of my left hand. The stiffness that stripe will add to the neck is just a side effect.

[Beate Ritzert]

Well, here the neck after the mod. The neck Thickness is now between 27 an 28 mm. Fretless. (On a fretted instrument the thickness of the frets should be substracted from the desired thickness.)

Plays well in all positions. The position of the reinforcement is slightly offset - tested prior to the mod with the piece of spruce shown above. Feels well, plays well, and the reinforcement is light enough not to affect the balance noticeably . B string seems to have improved a bit.

[Bob Francis]

Is it as comfortable as you had hoped?

[Beate Ritzert]

It is even a bit more comfortable - the stripe is just at the position where the thumb belongs.

[David King]

And a new neck geometry is born...

[Jim McConkey]

Nothing new about an offset shape. I stole the idea years ago for my cittern, and love how it feels. The hand is nowhere near symmetric, why should a neck be? The simple answer is just that it is easier to mass produce.

[Beate Ritzert]

AFAIK, Rick Toone holds a patent on an asymmetrically shaped neck...

BTW, that neck never was symmetric; on the bass side it was always 1-2mm stronger (and it is older than Toone's patent). Intentionally thicker, and i am unhappy that i was not more consequent at that time.

[Bob Francis]

As a bass player that doesn't care for skinny necks I think this is a great mod.

[Clay Schaeffer]

"Feels well, plays well, and the reinforcement is light enough not to affect the balance noticeably . B string seems to have improved a bit."

WIN, WIN, WIN!


AFAIK, "Rick Toone holds a patent on an asymmetrically shaped neck..."

Citterns had asymmetrically and weirdly shaped necks long before Rick Toone was alive. His patents are probably about as valid as Novak's.

[Beate Ritzert]

There is another thing in acoustic Guitar making patented recently (by Taylor) - a tiny nut on the bottom side of the top and close to the edge. Functionality apparently more or less equivalent to the recurve of archtops and violin tops. And done by at least some German luthiers for years.

There new patented or patend pending A bracing scheme appears to me like a slight extension of the A bracing used in acoustic Hawaii guitars from the forties.

How silly are the administrators in the patent offices?
(sleeve guarded pavians with red asses crying wildly all the time? (that comparison comes from my time as a program manager at the Deutsche Forschungsgemeinschaft))

[Clay Schaeffer]

I think there are so many patents applied for and so few patent examiners that they just grant the patent and let people fight it out in court to see if it is valid. Where there is prior art and I'm not copying something exactly like what someone else is doing I don't worry about patents. If I had a commercial enterprise churning out multiple copies I'd be more concerned.