Neck backbow problem

Discussion in 'Tele Home Depot' started by peter762033, Oct 18, 2019.

  1. peter762033

    peter762033 TDPRI Member

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    Hi,

    I've got a neck through guitar that has a backbow issue.
    I've already had a go at straightening the neck by clamping in a severe relief postion and applying heat. It seemed to work for a while but the neck has slowly crept back to flat/backbow posistion.
    Unfortunately the neck has a one way truss rod which isn't very helpful.
    Has anyone got any other tips for rescuing this guitar?

    Thanks,
    Pete
     
  2. jfgesquire

    jfgesquire Tele-Meister

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    Neck through, but is the fretboard a separate piece or is that one piece as well?

    Just a ridiculously expensive and time consuming thought...if it was a separate rosewood fretboard you could really learn some lutherie skills and remove the fretboard, and re-glue it while the neck has some forced relief. Maybe add a two way truss rod while you're doing open heart surgery.

    Maybe install some 13-56 gauge strings and let it sit in a 50% humidity room for a month? Set it up to play slide on it?

    Sent from my LG-H932 using Tapatalk
     
  3. charlie chitlin

    charlie chitlin Doctor of Teleocity Silver Supporter

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    You don't always need to remove the fretboard; if it's held together with hide glue,enough heat to melt the glue is enough.
     
  4. jfgesquire

    jfgesquire Tele-Meister

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    That's what I meant by removing the fretboard.

    I've actually ironed a few acoustic bridges off for reglue and steamed a broken neck off a 1941 Kay upright bass.

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  5. charlie chitlin

    charlie chitlin Doctor of Teleocity Silver Supporter

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    Yeah...at that point, it's all but removed.
    Being the neck fretboard has probably settled into where it wants to be, you could plane it flat.
     
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  6. rangercaster

    rangercaster Poster Extraordinaire

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    If the guitar is worth the effort, I would recommend a master luthier fix it ... Of course, this won't come cheap ...
     
  7. Ronkirn

    Ronkirn Doctor of Teleocity Vendor Member

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    Doing it correctly will require "Brain Surgery" as suggested above.... remove the fingerboard... install a two way truss rod.... then re-glue the fingerboard, using a glue that will release under heat ... let it "dry/cure" for a couple of days... level the frets... and rock on..

    rk
     
  8. hopdybob

    hopdybob Tele-Afflicted

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  9. Freeman Keller

    Freeman Keller Tele-Afflicted

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    Ron, add to that a probably refinish or at least repair of the finish - it will be very difficult to do this without some damage.

    Back to the OP - with the truss rod completely slack what is the relief? I know it will be a negative number, I'm trying to determine how much wood you could remove from the middle of the f/b to level it.
     
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  10. ElJay370

    ElJay370 Tele-Holic

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    Maybe going up a string gauge or two will pull the neck into some relief. You'll have to toughen up your playing a bit, but you'll get used to it.
     
  11. guitarbuilder

    guitarbuilder Telefied Silver Supporter

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    Same answer as the other thread you started in DIY which now appears to be gone :). A heat lamp near the fretboard to soften the glue. Clamps are in place to force the wood to slip once that happens. You have to mask the finish or it will be ruined. I've never done it but seen it done in a repair shop. It may not be a permanent fix though.
     
  12. Freeman Keller

    Freeman Keller Tele-Afflicted

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    FWIW, I have removed a fretboard from a neck that was under construction. Glue was Titebond, I used my silicon side bending blanket for heat (I bend sides at 350 to 400 F, don't know what the temp of the f/b was). Worked my pallet knives between the neck and f/b, some slight damage to the wood. If the neck had been finished or if there had been plastic binding there would have been sever damage.

    IMG_5062.JPG IMG_5063.JPG
     
    Last edited: Oct 18, 2019
  13. Freeman Keller

    Freeman Keller Tele-Afflicted

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    Pete, the easiest and safest is to simply slacken the truss rod, pull the frets and sand the fretboard flat without removing material from either end. Re-radius the board, deepen the fret slots and refret it. Let the strings pull some relief back into the neck, use the truss rod to control it. I would be very comfortable doing that up to maybe 50 or 60 thousands of negative relief. It will look wonky along the sides of the neck but that is the least invasive method of fixing it.

    I'm doing a refret right now and its got a little hump ant the 14th fret (body joint on an acoustic). I simply sanded it out and deepened the slots slightly. Happens all the time.
     
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  14. peter762033

    peter762033 TDPRI Member

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    Wow thanks for all of your replies some really good ideas there, much appreciated!

    The neck has a separate Ebony fret board so the fret board removal method could be an option.

    Yep I've strung it up with 11's tuned to standard which seemed to work at first but again it slowly crept back.

    I've had a thought that maybe the finish on the back of the neck could be part of the problem. It's been clear coated in with the rest of the guitar and the fret board is oiled. I'm thinking the fret board could be picking up moisture where as the back of the neck is sealed in clear coat. Could that theory be correct?

    The refret/re radiusing idea sounds good, I'll have to weigh up which method is best. The fret board has a compound radius just to further complicate things haha.
     
  15. Freeman Keller

    Freeman Keller Tele-Afflicted

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    You still didn't tell us how much back bow you had. And a picture of the guitar would be helpful - you said it was a thru neck which could make a difference in the approach.
     
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  16. telemnemonics

    telemnemonics Doctor of Teleocity Ad Free Member

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    Agreed more details on the whole guitar would help.

    First would be how many thousandths of back bow you have.
    I'm guessing it's a modern jumbo fret neck, which for the lowest price you could dress .005 off the end frets and get it playable.

    Next I would not assume that your attempt to straighten it with heat and clamps means that it cannot be done.
    Might be that you just didn't heat enough of the neck and board/ didn't get it hot enough/ didn't bend it enough.

    Another thing I've found is that on necks that require no tension on the truss rod, I set the nut snug so it won't rattle.
    But string tension then puts tension on the truss rod, so you may need to simply loosen it more.
    Assuming though that it's a headstock adjust you may have already done that.

    I'm also guessing it was never refretted, which can cause back bow and even more likely on an ebony board where the wood doesn't crush much.
    In many cases you can just refret taking care to not make tight fret slot fits and the board will "push back" less, allowing tension to pull up some relief.
    If the back bow is regional you may only need to refret 1/3 of the neck.

    If the bow is more extreme than a few .001s you may indeed need to plane the board and refret, but again I'm guessing that if it almost plays; your back bow is at worst only .002"- .005".
    Or the bow was bigger and maybe your heat reset was done in dry winter months and then summer humidified/ swelled/ stiffened the back bow back in.
     
  17. peter762033

    peter762033 TDPRI Member

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    UPDATE:

    So I gave the neck another heat treat but used 2 irons instead of 1 as per hopdybobs post.

    I heated the neck for much longer this time, just over an hour, and kept it clamped for about 4 days after the heating. I can say it work amazingly! Before I had about 0.2mm of backbow with 11 gauge strings and now I have a huge 1.2mm of relief with the truss rod loose.
    I can probably now go back to 9's and tweak the truss rod accordingly.
    Thanks to everyone for your help, looks like this one was a success without major surgery!

    Cheers,
    Pete
     
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