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Wood combinations to avoid?

Discussion in 'Luthier's Corner' started by Tim Barber, May 17, 2003.


  1. Tim Barber

    Tim Barber Commercial User

    Apr 28, 2003
    Serenity Valley
    Owner: Barber Music
    I'm in the concept/drawing stage for a 7-string bass building project. This will be scratch-built bass #4 for me, not counting a couple of Frankenbass modification/rebuild projects. I've got some wood pieces lying around that I'm trying out in different combinations: figured maple, cocobolo, redwood burl, chechem, mahogany, walnut, wenge veneer etc. I know this is subjective, but has anyone found wood combinations that do not seem to work well tonally? I imagine some woods would have different resonances etc. that might not be compatible. Any ideas?

    TimmyB
     
  2. Jazz Ad

    Jazz Ad Mi la ré sol Gold Supporting Member Supporting Member

    IMHO, it's all about finding the good ratio between resonating woods (usually local clear woods like maple, poplar, alder, ... mahogany also falls into this category) and stiffening woods (harder exotic woods like purpleheart, wenge, cocobolo, ...)
     
  3. Suburban

    Suburban

    Jan 15, 2001
    lower mid Sweden
    Just keep your backbone (head string anchorage to bridge ditto) stiff and light.

    The rest is not as crusial, and the impact of the wood will demand on the shape of the body.

    ( Bassic Physics )
     
  4. JP Basses

    JP Basses

    Mar 22, 2002
    Paris FRANCE
    Suburban...this basic physics article is a must read!!!

    All is there man. Congrats and thanks for summing it up ;)

    I may add it to my signature!! :D

    Peace, JP
     
  5. Tim Barber

    Tim Barber Commercial User

    Apr 28, 2003
    Serenity Valley
    Owner: Barber Music
    Wow, thanks for the info everyone :) That gives me a lot to think about, especially the article. I'm curious about the stiffness of the neck being greater for horizontal laminates than vertical ones. Does anyone know of a production bass that uses horizontal neck laminates? I can't think of one offhand, but the idea seems sound. Hmmm...



    (...puts on thinking cap and retreats into the shadows)
     
  6. JP Basses

    JP Basses

    Mar 22, 2002
    Paris FRANCE
    hehe...

    Look at my site man ;)

    JP
     
  7. Tim Barber

    Tim Barber Commercial User

    Apr 28, 2003
    Serenity Valley
    Owner: Barber Music
    oh...

    sweet!
     
  8. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Maryland
    Owner: FBB Bass Works
    I'm interested in the horizontal laminate thing too:

    "experiments show, that a horizontal laminate of equal boards are stiffer than a vertical!"

    JP, you are doing this type of neck? Who did the experiment? Did they write it up?

    I guess I'd be worried about creep issues and the truss rod pushing on a glue joint.
     
  9. JP Basses

    JP Basses

    Mar 22, 2002
    Paris FRANCE
    Yes Matt, I'm doing Horizontal lamination. Not exactly like picture on Suburban's site though.
    Take a look at my "instruments" page and you'll find a drawing. looking at the back shot in the gallery should help to understand.

    I went this way for stiffness but also because it made sense for me for building ease and smart use of wood ressources. In fact, we only need neck "stiff enough" and using wenge or padauk would allow not to use any lamination (IME and IMO).

    I've made some experiments on laminations when I was studying mechanical engineering soem years ago.
    Also on some metal to metal glueing experiments, I discoverd how much stronger the glue joint was while working in traction rather than in torsion.
    Same here, with horizontal lamination, the glue joints work in traction. Suburban principles put stiff material to use on both outer and inner faces of the neck, where compression and traction efforts are at their best level.

    FWIW, also have a look at linc luthier's patents. He uses a special horizontal lamination. patent n°5,445,058

    Peace, JP
     
  10. Suburban

    Suburban

    Jan 15, 2001
    lower mid Sweden
    JP is spot on.
    You can find additional info from all the users of horisonal (traction) laminated wood beams for buildings and other construction work.
    You will find a stiffness ratio of about 1.2 overall, horisontal over vertical laminations.
     
  11. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    Matt, I was thinking the same thing about the trussrod and the glue joints. But -

    I think that the truss rod is normally pushing on a glue joint anyway- the joint between the fingerboard and the main neck blank. In fact, in a normal situation where the trussrod is providing a backward bending to counter the frontward string bending, it is pushing up on the underside of the fretboard in the middle of the length of the neck, and down into the neck at its two ends. (I'm thinking of a double-action trussrod here.) With a horizontally-laminated neck, you do have more of these joints. They are nearly identical, differing in that the to the neck blank-fingerboard joint might have more or less glue area than the "rear" joints, depending on the profile of the neck.

    At first I thought that the horizontal laminations, in combination with varying wood species as JP uses, might not be a good idea - because as the different woods respond differently to temperature and humidity changes, the neck might bow and need trussrod adjustment. However, two things contradict this: one, your average neck is a horizontal laminate construction, of non-uniform woods, by virtue of the fingerboard lamination; and two, JP (and similarly, Linc Luthier) has been successfully doing this, and seems that it works!
     
  12. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Maryland
    Owner: FBB Bass Works
    Interesting points, all. JP - it looks to me like the main part of the neck (under the fingerboard) is one piece on your basses. I could be wrong. That's the thinnest part of the neck. What I still worry about with the horizontal laminations is that if you were to round out the back of the neck for a more "C" shape, you lose some of the glue joint's surface area (compared to the fingerboard).

    Anyway, I obviously worry about things like that too much, since there are basses out there that do it successfully. Interesting discussion, though!
     
  13. JP Basses

    JP Basses

    Mar 22, 2002
    Paris FRANCE
    Yeah Matt, you're right. one piece for fingerboard, one piece for neck core (thickest piece in my necks, 10mm) and one pirec for neck back (5mm). Then I glue on a neck heel and a headtsock back.

    Never had any glue joint resistance issue on the neck, even when tightening the truss rod firmly.


    Sidenote: Pilotjones, no stability problem here. In fact with care taken in choosing species, matching grain and when glueing with alternate grain directions, the necks are SUPER stable ;)

    Peace, JP
     
  14. Bass Kahuna

    Bass Kahuna

    Dec 3, 2002
    West Lafayette, Indiana
    Luthier, Custom Builder
    Great, informative thread!

    Hey JP, two questions for you.

    1 - Do you use a regular (traditional) truss rod in your necks or the double expanding type?

    2 - Do you put in the popular carbon or steel stiffening rods as well, or is the horizontal laminate strong enough that you don't need them?

    Thanks!

    :^)~
     
  15. JP Basses

    JP Basses

    Mar 22, 2002
    Paris FRANCE
    I use Stewmac spoke nut hot rods. I've tried many deisgns ncluding my ouwn home made truss rods and stew mac are the best I found.

    No carbon nor steel rods in there. Just stiff and stable woods.

    I would use a one piece wenge or padauk neck with complete succes with no carbon.

    Peace, JP
     
  16. Bass Kahuna

    Bass Kahuna

    Dec 3, 2002
    West Lafayette, Indiana
    Luthier, Custom Builder
    Thanks a ton! I am planning on using those as well, just curious as to what you found works best with your horizontal laminated necks.

    :^)~
     
  17. Would horizontal lamination work for a neck-thru?
    I think that JP doesn't use neck-thru but is it realisable?
     
  18. JP Basses

    JP Basses

    Mar 22, 2002
    Paris FRANCE
    Of course it is!

    Lin Luthier builds nothing but Neck Thrus :D

    JP
     
  19. Suburban

    Suburban

    Jan 15, 2001
    lower mid Sweden
    Definitely & easily.
     
  20. tonrutoo

    tonrutoo

    Apr 18, 2003
    thanks for the"backbone",Suburban;very informative.
    i was wondering if someone would be so kind as to elaborate on the weight issue concerning tuners,and bridges(?).
    my proposed set up is a wenge body,short scale goncalo alves neck,pau ferro fretless fingerboard-w-
    schaller bridge,sperzel tuners,brass nut.
    pyramid gold nickel flatwounds.
    thanks in advance.