Scarf joint on back of neck instead

Discussion in 'Luthiery, Modifications & Customizations' started by LiveOVErdrive, Apr 9, 2019.

  1. LiveOVErdrive

    LiveOVErdrive CNC hack

    Messages:
    2,367
    Likes Received:
    1,661
    Joined:
    Aug 17, 2016
    Location:
    Minneapolis, MN
    You know how on most headstock scarf joints you make the angled cut, flip the headstock piece, and glue it across the angle-cut face of the neck blank?

    If you glued it instead with the angle-cut face of the headstock piece against the back of the neck, would it be stable enough? Seems like it would be fine.

    The reason I ask is because my guitar teacher was just complaining to me about how having the joint under the fretboard can cause problems. This seems like a good way to move it elsewhere.
     
  2. sezna

    sezna undermotivated

    Messages:
    1,258
    Likes Received:
    463
    Joined:
    Jul 3, 2013
    Location:
    Texas
    What kind of problems did he say it can cause?
     
  3. LiveOVErdrive

    LiveOVErdrive CNC hack

    Messages:
    2,367
    Likes Received:
    1,661
    Joined:
    Aug 17, 2016
    Location:
    Minneapolis, MN
    I think it was something about the joint shifting and warping the fretboard or something like that. Not sure. My 20+ year old Ibanez is like that and doesn't have a problem. I'm mostly just curious.
     
  4. Deegatron

    Deegatron SS.org Regular

    Messages:
    632
    Likes Received:
    157
    Joined:
    Jun 29, 2013
    Location:
    Edmonton, AB
    What your explaining is common practice for classical guitars but never seemed to catch on with most electrics that I'm aware of.
    It seems to me to be yet another one of those cases where some guy's do it this way and others do it that way.... no real theoretical advantage to either method.
    The only real world advantage would come down to execution (a tight clean joint is a tight clean joint period.) perhaps your instructor had a scarf jointed neck with a poorly done joint and he blamed the joint instead of the poor build quality. YMMV.
     
    LiveOVErdrive likes this.
  5. odibrom

    odibrom .

    Messages:
    3,128
    Likes Received:
    977
    Joined:
    Dec 2, 2014
    Location:
    Unknown
    With the conventional joint (meaning that the fretboard also glues on the headstock piece), the fretboard also provides additional gluing force, locking the headstock piece in place and strengthening the joint... given that the fretboard is thick enough (about 5mm or more?) and is a strong wood (which normally is).

    If the headstock piece is glued on the back, the fretboard won't lock it in place and if there happens to be conditions for it (lots of head and humidity?), it has a bigger chance to snap out.

    ... in my opinion, that is...
     
    LiveOVErdrive and BlackMastodon like this.
  6. BlackMastodon

    BlackMastodon \m/ (゚Д゚) \m/ Contributor

    Messages:
    5,773
    Likes Received:
    790
    Joined:
    Sep 26, 2010
    Location:
    Windsor, ON
    ^This. I never understood the argument for having the scarf piece glued on the back. It's pretty simple mechanics, and you can do a quick Google search of "broken Gibson headstock" and see how well it works.
     
    Hollowway and odibrom like this.
  7. KnightBrolaire

    KnightBrolaire Drink Sunny D, pet kitties.

    Messages:
    11,264
    Likes Received:
    8,812
    Joined:
    Mar 19, 2015
    Location:
    MN, USA
    So you guys are talking about A, rather than B, correct?
    [​IMG]
     
  8. LiveOVErdrive

    LiveOVErdrive CNC hack

    Messages:
    2,367
    Likes Received:
    1,661
    Joined:
    Aug 17, 2016
    Location:
    Minneapolis, MN
    Like this.

    IMG_20190409_100059.jpg

    Makes a whole lot of sense that the fretboard strengthens that joint. Plus it seems like it would be easier to plane it smooth.
     
    aesthyrian and odibrom like this.
  9. Mathemagician

    Mathemagician SS.org Regular

    Messages:
    2,492
    Likes Received:
    1,374
    Joined:
    Jul 6, 2014
    Location:
    Tampa, FL
    I love this dorky forum.
     
  10. Deegatron

    Deegatron SS.org Regular

    Messages:
    632
    Likes Received:
    157
    Joined:
    Jun 29, 2013
    Location:
    Edmonton, AB
    White it is true that the modern style gets support from the fretboard you're neglecting to acknowledge that most builders will add a headstock veneer which is usually quite thick (0.100" or so) Plus some builders put a headstock veneer on the back of the headstock as well meaning the classical scarf joint would receive support on both sides where as the modern style would receive only support on one side.
    The modern style also receives force in line with the joint (which technically could cause cold creeping under the right conditions)
     
    KR250 likes this.
  11. LiveOVErdrive

    LiveOVErdrive CNC hack

    Messages:
    2,367
    Likes Received:
    1,661
    Joined:
    Aug 17, 2016
    Location:
    Minneapolis, MN
    Clearly an angled box joint is the correct decision :)
     
    odibrom likes this.
  12. spudmunkey

    spudmunkey SS.org Regular

    Messages:
    1,680
    Likes Received:
    1,236
    Joined:
    Mar 7, 2010
    Location:
    Near San Francisco
    If the only glue-up surface is half end-grain, it's more likely to fail. By overlapping the fretboard over the joint, you're adding at least one "proper" glue-up surface, of edge/side grain to edge/side grain.
     
    Hollowway likes this.
  13. odibrom

    odibrom .

    Messages:
    3,128
    Likes Received:
    977
    Joined:
    Dec 2, 2014
    Location:
    Unknown
    @LiveOVErdrive yep, IMO your option A is the way to go, for it is stronger against the string pull force.
     
    LiveOVErdrive likes this.
  14. IGC

    IGC SS.org Regular

    Messages:
    714
    Likes Received:
    207
    Joined:
    Dec 31, 2016
    Location:
    Cleveland,ohio
    I always fancied the idea of hard wood doweling or tongue and groove for headstock scarfs.
     
  15. MoonJelly

    MoonJelly a subtle stinging sensation..

    Messages:
    1,204
    Likes Received:
    663
    Joined:
    Mar 11, 2016
    Location:
    North Atlanta, GA
    Taylor did a finger jointed headstock, but that just makes the glue join stronger. If it breaks, it will more likely break next to the joint than at it. They used to do this:

    [​IMG]

    But kept having this problem:

    [​IMG]

    [​IMG]

    You know how they solved for it on the latest model? Lamination. by adding a lamination of the same wood species to the whole back of the head, it actually makes the whole headstock more resilient to breakage.

    [​IMG]

    The funny part of this story is that the Taylor diehards were freaking out about the design change. "Is this cost savings for lower end models or what?" When in reality it's an improvement...

    Where there is glue, there is reinforcement, when done properly.

    Great article on the basics:
    https://www.gluedtomusic.com/blog/1/headstock-and-scarf-joints-explained/
     
    BlackMastodon likes this.
  16. Defyantly

    Defyantly Maybe

    Messages:
    447
    Likes Received:
    239
    Joined:
    Feb 15, 2018
    Location:
    Idaho
    You should be the first (that i have seen) to make a headstock joint that connects via a dove tail. I think that would look amazing probably decently strong as well. I would try it but its a little out of my capabilities. :cond:
     
  17. MoonJelly

    MoonJelly a subtle stinging sensation..

    Messages:
    1,204
    Likes Received:
    663
    Joined:
    Mar 11, 2016
    Location:
    North Atlanta, GA
    It's been done. Not to mention the "bird's beak" joint!
    [​IMG]
     
    Lemonbaby and Defyantly like this.
  18. LiveOVErdrive

    LiveOVErdrive CNC hack

    Messages:
    2,367
    Likes Received:
    1,661
    Joined:
    Aug 17, 2016
    Location:
    Minneapolis, MN
    As pointed out in the Taylor post though there probably wouldn't be any benefit.
     
    MoonJelly likes this.
  19. MoonJelly

    MoonJelly a subtle stinging sensation..

    Messages:
    1,204
    Likes Received:
    663
    Joined:
    Mar 11, 2016
    Location:
    North Atlanta, GA
    Nice! Somebody gets it :lol:
     
    Hollowway likes this.
  20. LiveOVErdrive

    LiveOVErdrive CNC hack

    Messages:
    2,367
    Likes Received:
    1,661
    Joined:
    Aug 17, 2016
    Location:
    Minneapolis, MN
    Just do an end grain butt joint and call it a day. :)
     
    BlackMastodon and Hollowway like this.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.