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how do I fix this?

Discussion in 'Luthier's Corner' started by Lizooki, Sep 14, 2008.


  1. Lizooki

    Lizooki

    Feb 24, 2008
    I was told to cross post here so here ya go.......



    Fixed and painted....

    SL730113.
     
  2. Jazzdogg

    Jazzdogg Less barking, more wagging!

    Jul 29, 2006
    San Diego, CA
    QUOTE: I don't wanna just glue and clamp. It failed once, it'll fail again.
    I was thinking of clamping and glueing, then drilling and glueing pegs through the joint from the fretboard side, just not all the way through. END QUOTE

    What, exactly, was done the first time the repair was attempted? For example: What was done to prepare the surfaces to be re-glued? What kind of adhesive was used? How was the clamping done? How many clamps? What kind of clamps? How were the clamps spaced? What kind of clamping cauls did you use?

    You get the idea ;)
     
  3. Agreed, can you elaborate on how the initial repiar was done. Simple clamping with improper glue will result in this repeating itself time and time again.
     
  4. Lizooki

    Lizooki

    Feb 24, 2008
    I don't mean the repair failed......the original scarf has failed.
    AFAIK, it has not been repaired.
    I want to make the repair stronger than the original scarf, if possible.
    Or would it be sufficiently strong to just clean it up, glue and clamp?


    Matt
     
  5. Jazzdogg

    Jazzdogg Less barking, more wagging!

    Jul 29, 2006
    San Diego, CA
    The repair isn't "difficult," but there are a few details to address if you want it to work.

    As you may have inferred from the questions I asked in my previous response, there are several variables to consider. To begin with, the old glue has to be removed completely or new glue won't stick, and if you clamp it improperly, it's possible that you'll introduce a warp that wasn't there before. Were I to make that repair, it's unlikely that I'd reinforce the joint with dowels after the pieces had been glued-up - shouldn't need to if the rest of the job is done right.

    If you have specific questions, please ask. Good luck!
     
  6. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    I'm guessing the scarf opened up by itself, but not enough to crack the fretboard, and then you separated the joint between the fretboard and the main neck shaft?
     
  7. Triad

    Triad Supporting Member Commercial User

    Jul 4, 2006
    Europe
    Luthier - Prometeus Guitars
    Lizooki: I don't have a huge experience with repairs... but I'd act this way:

    1) Removing all the glue on both sides of the joint;
    2) Put something on the truss-rod to keep it free to move (masking tape);
    3) Making of wooden "C shaped" pieces that follow the neck's shape and help you to clamp it correctly;
    4) Epoxy glue! :D and lots of clamps.

    Take your time and act without rush... I'm sure you can do it. Or, if you really don't feel able to do it, have it fixed by a pro.
     
  8. Lizooki

    Lizooki

    Feb 24, 2008
    Slow is OK...I'm not in a hurry...I have 4 other basses to play. :bassist:

    But I have trouble paying to fix a $25.00 bass. :spit:



    Yep, you got it. I removed the fretboard just to see how bad....plus I figured it would have to be removed to fix anyway.
    There is a thin sliver of a crack in the fretboad right where the scarf opened, on one side of the trussrod. I figured I would work as much glue into the sliver as I could then let it go.


    Suggestions?
     
  9. Pretty much what Triad said, except that I would first remove the headstock from the fretboard, glue up the scarf joint (epoxy!), then rout channels in the neck for CF rods before gluing the fretboard back on. I'd want the rods as far toward the nut as possible without busting through to the headstock.

    Using CF might be a little on the expensive side though for a $25 bass.
     
  10. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    What does anyone think of the idea: After regluing the scarf, before regluing the FB, plane maybe 1/16" of neck surface off, and glue in a 1/16" veneer, then do the FB. This would put atleast some unbroken wood between the scarf line, and the crack in the FB.
     
  11. mikeyswood

    mikeyswood Banned

    Jul 22, 2007
    Cincinnati OH
    Luthier of Michael Wayne Instruments
    You have an easy fix. Get some Franklin Hide Glue and and reglue the joint. Make sure that you have enough clamps on the fretboard and the joint.

    That type of head joint is a quick and easy way to produce a back tilt from a 3/4" neck. The glue that is on there could be hide glue or yellow glue. Either way I would hide glue the entire neck back together to keep the angle perfect.
     
  12. Arx

    Arx

    Jan 22, 2008
    I'd clean the glue off and reglue/clamp. It failed before because it wasn't done correctly. a good woodglue joint is stronger than the wood. I've seen photos testing it, and the wood will actually rip off around the joint before the joint will separate.

    Scarf joints actually make sense. they save wood, and don't leave your headstock with a cross grain to it. I'd trust a scarf more than a back tilted unscarfed neck.
     
  13. Lizooki

    Lizooki

    Feb 24, 2008
    I went ahead and completely separated the board and the neck pieces. Cleaned every thing up......I think I may have removed a bit too much wood in trying to clean off the old glue, but everything seems to have went back ok.
    The finger board goes back today....we'll see then.
    I'm still thinking I'm gonna go w/ light gauge strings for piece of mind. ( I'm not a luthier or wood worker)

    Thanks for the replies guys!

    Matt
     
  14. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    By all accounts, liquid hide glue is the last thing you should use in luthiery. There are many accounts of having to throw away a neck after using it. One just recently.
     
  15. Arx

    Arx

    Jan 22, 2008
    yep, just because it's old, doesn't automatically make it good. ;)
     
  16. Jazzdogg

    Jazzdogg Less barking, more wagging!

    Jul 29, 2006
    San Diego, CA
    I've been successfully using both hot hide glue and pre-mixed hide glue for more than 30 years. Hide glue has been used for centuries and remains in widespread use today by luthiers worldwide, particularly in the manufacture and repair of violins, violas, celli, and upright basses.

    While hide glue is not the most appropriate adhesive for every glue-up, it remains remarkably useful in a wide variety of applications, even in the 21st century, and there are several modern adhesives that still cannot match hide glue's numerous strengths and versatility.
     
  17. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    US-NY-NYC
    Yes, I know that hot-pot hide glue is fantastic in many applications. It's also used throughout piano actions, in which strong physical demands are put on the joints.

    Also that every glue has it's place.

    So far, I've only heard negatives, warnings and failure stories about liquid hide glue. I definitely respect your woodworking experience, so, what would you consider appropriate applications for liquid hide glue in luthiery? From what I've gotten so far, it seems as though it might be good for non-stressed or ornamental joints, but not for anything structural. Is this right in your view? Or way off base?
     
  18. Fasoldt Basses

    Fasoldt Basses

    Mar 22, 2005
    Stevens Point, WI
    Karl Thompson, Builder (Formerly Fat Karl)
    Hide glue depends on protein bonds to do the actual work of sticking - protein bonds hold the glue together, and these bonds can last for centuries. Liquid hide glue contains urea, to keep the glue in liquid form and bypass the complicated process of preparing hot hide glue. Urea, however, eats away at the protein bonds in the glue and weakens it significantly. Over time, the urea continues to weaken the glue joint to the point of failure.
     
  19. Arx

    Arx

    Jan 22, 2008
    And knowing is half the battle. :)

    Hooray for science.

    Ordinary yellow wood glue, Titebond, Probond, whatever.

    Strong, cheap, common, and easy.

    Why mess with it?
     
  20. The hide glue comment reminds me of Ken Smith's argument on why maple is the better and ONLY choice for a neck wood. Tradition that is hundreds of years old.
     

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