Calling all Experts - Maxed truss rod and neck bow repair

Discussion in 'Luthier's Corner' started by RMay, Jan 15, 2009.

  1. Please I really could use your expert advice. I am not feeling confident with this repair as I am concerned the larger issue is the neck's bow is placing too much of a force on the truss rod.

    I received a G&L neck that has a forward bow. Currently there is NO tension on the neck, there is .024" relief measuring at the 9th fret between 1st fret and the 21st fret.
    Is the .024" relief (credit card thickness) too strong of a bow for a truss rod to hold near straight?

    In addition, the truss rod was overtightened resulting in a bump with two hairline cracks between the string nut and 1st fret in the rosewood fretboard .
    It was overtightened..this assume is why the bullet truss rod nut nearly exploded through the fretboard. Or could the bow be too strong a force pushing fretboard outward at the nut?

    The good news is the truss rod works and the threads are fine. I prepared a few steel washers to be placed before the bullet-style nut, these washers easily slide on/off the truss rod.

    I have the liquid super glue and the new gel super glue for the cracks in the rosewood.
    Is the liquid super glue a better choice for this repair?

    I got an idea that I may try..that is packing the truss rod cavity with plastic wrap to protect the rod in case any glue seeps through the crack into the cavity.

    Thanks - Richard
  2. I had searched Talkbass forums, the internet, and asked local Luthiers before posting here. This is real.
    When I proceed in repairing the neck I'll be watching for a fretboard explosion :eek:.

  3. 2x4strgkramers

    2x4strgkramers Guest

    Dec 15, 2008
    Steaming and pressing is about the only way I know of to fix a really screwed up neck but if that actually works is questionable.
  4. Nelson Guitars

    Nelson Guitars Guest

    Aug 14, 2006
    Novato California
    Custom builder
    It works but with dry heat not steam. Steam will screw with the wood and finishes big time. A silicon heat blanket, a flat surface to clamp to and the least amount of heat to do the job. Some experience helps. I would recommend you pay someone who knows what he is doing to take care of this or don't bitch if things don't go well.

    Greg N
  5. AlembicPlayer

    AlembicPlayer Im not wearing shorts

    Aug 15, 2004
    Pacific Northwet, USA
    the truss rod condom is a good idea, Gibson uses them in the custom shop.
  6. I agree.
    The dry heat method does work but the glue must be malleable. This is a 24 yr.old neck so the glue may have turned to dust years ago.

    Are you guys saying then the neck's bow is too far gone heating is the only reasonable option? sorry, if I am dense this morning.

    A circle of local Luthiers believe I can handle this job alone. I realize it be too expensive to pay either of them and there would be no guarantee of a repair. They are not sure if the neck is too far askew at this point to not attempt to use the truss rod. They say I should go for it and keep them in the loop. Oh I am prepared to accept the worst outcome - no bitching but enjoy the experience.

    I appreciate the replies. Please keep'em coming. Brainstorms are welcome!

  7. I want to make it known I did not create this mess. This is the condition of the neck in which I received.

  8. XylemBassGuitar

    XylemBassGuitar Supporting Member Commercial User

    Aug 14, 2008
    Durango, CO
    Owner and Operator, Xylem Handmade Basses and Guitars
    Can we get some pictures of the "bump" in the fretboard?

    If you're apprehesive about heating and pressing to reduce/eliminate the bow in the neck, you could also try this:

    Clamp some of the bow out of the neck (without heat), then tighten the truss rod.

    This way, you are taking most/all of the pressure off the truss rod so that it doesn't have to move the bow out of the neck, but just has to hold it in place once it's tightened. Sometimes this is enough to get the neck back in shape...

    Of course, I do agree that things could go horribly wrong, especially depending on the extent of the damage to the neck. Be careful...
  9. lethargytartare


    Sep 7, 2004
    are the cracks between the nut and fret 1 with the grain or across it?

    the glue in a G&L neck is not going to turn to dust in 24 years. And if it had disintegrated in any way, you wouldn't have a fretboard on the neck at all. and I can't think of any reason the glue would have to be "malleable" in order to attempt the adjustments being described -- if that were true, no bass older than 24 years would be able to handle restringing and truss adjustments.

    but I don't get the input from the luthiers you know -- they say they don't know if it's fixable, but they do know you can handle it? what does that mean? What did they say THEY would do if they had to work on it? You're going to get the best input from people you can actually show the instrument to in person (i.e. your circle of luthiers) than folks on th web who are working off a description.

    And let's think about this: if "overtightening" the truss nut damaged the fretboard, doesn't it seem that adding washers will only enable you to put more pressure on the same spot -- why wouldn't the same damage occur again?

    I like Xylem's idea the most -- clamp the pressure out of it, tighten the nut, see what happens. Glue the fretboard as well as you can first, of course.

    What's the neck worth, anyway? 50 bucks? As it is now, 0 and it's unuseable. and a repair will surely cost more than just buying a used one to replace it. So, with nothing to lose, you're probably being overly cautious about this.

    Pics, pics pics. And updates -- good luck!

  10. The cracks are with the grain. They are not visible under low light and the bump is tiny.

    Dry heating - the glue between the neck and fret board would need to have the capacity for adaptive change. Do you know that the glue will not deteriorate under high heat? I have to emit I don't know how much heat will be used, so my opinion is restringing and truss adjustments do not compare to altering the wood & glue under heat. EDIT: Sometimes I can be hardheaded. I just finished reading about clear 250w heat lamps applying them to necks. lethargytartare, I see the light[pun].. Heating could be correct the way to fix it. I must read more on the subject.

    The repairmen never said they don’t know if it is fixable. They have seen it. What they don’t know is that the truss rod will hold the neck straight.

    If they had to work on it they would
    1st. Repair the cracks in the fret board.
    2nd Add a washer to the truss rod. Adjust the truss, if the truss rod can’t straighten the neck …
    3rd Clamping + Heating, if that does not work….
    4th. Remove the frets and the fret board, replace the truss rod, glue the fret board back on and clamp the neck straight. Afterwards they add frets. There was one person that said he would not fully remove the fret board from the neck.

    Yep -- why wouldn’t the damage reoccur? This is why I am not comfortable with just adding a few washers to get more room for adjustment. You're the first person beside myself to ask this question.

    +1, I like Xylem's fresh idea. I clamp it straight and tighten the nut. Then add a little pressure after each 24hr period.

    Pics will be posted.. I'm now gathering the materials for my homebrew jig/clamp.

    Thanks for your replies and take care,

  11. 2 hairline cracks in the fretboard.. The longest crack stretches from the nut to the 1st fret the other crack is a half-inch long. Both are difficult to see under low light.

    That is plain plastic-wrap seen inside the rod cavity. I wrapped it around the threads of the truss rod and packed the cavity as protection from the glue.

  12. Here is the bow. I placed a straight edge along frets 1-21, the pic shows only the gap between frets 5 - 12.

  13. Just a few materials for the job.

  14. I found some (4) 4mm stainless steel washers at the HD. I bored them out to 10/24" so they slide on/off the truss rod.

  15. I suspect the reason for this is that the fretboard wasn't fully cured when it was originally glued up. Over time it shrank, causing the forward bow.
    This in turn led someone to drastically overtighten it. If it has that much forward bow with no string tension I think you'll need to remove the fretboard, allow the neck to relax, and re-glue the board back on. Good luck.
  16. found the rubber at the HD in the plumbing aisle. this will be used as a cushion between the clamp block and neck. Halves are glued together to increase the thickness.

  17. A homebrew jig/clamp. it works well. those are black rubber dampers i found. I cut them to size on a band saw.

  18. a straight edge placed along the board to check for a straight neck

  19. 2x4strgkramers

    2x4strgkramers Guest

    Dec 15, 2008
    Hot knife the fret board off. Press the neck. Remove the frets press the fret board re setup everything and go from there.
  20. I should have made this thread a poll... as I would have 2 votes for removing the fretboard.