Advice on a little repair job...

Discussion in 'Luthier's Corner' started by whero, Aug 20, 2020.

  1. I've done plenty of setups on plenty of basses, but I've never tried anything "luthiery" before, so I'm looking for some advice. Here's the situation...

    I have an acoustic guitar. It's a Cimar (an old Ibanez sub-brand) so it was pretty cheap when I bought it new. And I bought it when I was about 14 or 15, which makes it around 45 years old, so I'm sure it's now worth two thirds of #&@% all, as they say. Because of this, I don't want to take it to a proper luthier and pay way more for a repair than the whole guitar is worth. So I thought I'd give it a crack myself. What have I got to lose?

    The problem is that the fretboard has separated from the neck. It's still joined at the nut, and again from about 1cm after the neck joins the body, but for the length of the 15-odd frets in between there is a gap that's about 3mm at it's widest.

    To show that the fretboard is completely separated, the light bits I've marked in this second photograph are the daylight shining through from the other side.

    So I'm thinking: I should just take the strings off, get any dust or loose material out of the gap, slip some glue in there, clamp it, and wait. It sounds easy when you just say it like that. But I'd love some advice from people who actually know what they're doing, because I don't. The immediate questions I have are:
    1. What glue should I use?
    2. Will the truss rod be "exposed" under the fretboard, i.e. should I be careful about glue down the centre line of the neck, in case I "seal" the TR in place?
    3. Is it actually repairable, or is this already a write-off?
    But I'm sure there are plenty of other things I haven't thought about, so all and any advice will be gratefully received.
  2. Yes it can be fixed. What you suggest is correct. I would destring it and gently pull up that fretboard and see if it will pop loose at the nut. Either way, loosen the trussrod and dry fit clamp the fretboard down and make sure it lays down perfectly flat. If so, inject glue and clamp. Don't glue up the trussrod just the neck and fretboard. Exercise bands or bike inner tubes make great clamps. If that board won't lay down flat, it should come off. Thats more involved. Titebond wood glue. Take lots of pics and post back. Test fit and dry clamp everything a couple times to check the fit and alignment. Ideally, clamping a straightedge to the top of fretboard when gluing is preferred as it minimizes the need to level the frets afterward. Post back with what you find.
    whero likes this.
  3. dwizum


    Dec 21, 2018
    Personally I'd go ahead and take it off. There's no telling what kind of glue residue mess is happening in there and your repair may either not hold, or not be perfect (if reside causes the board to not sit flat against the neck).

    Plus it's just SO CLOSE to being off, it's bugging me just to look at those photos because I want to pull it off myself. It's like a bad scab. You just need to rip that sucker off!

    Very careful use of a heat gun on low pointed at the fretboard while you carefully slip a scraper underneath it will pop it right off. Then you can clean and level the neck and the back of the board and glue it back on for real. If you're careful with the alignment and the glue job you may get away with only a minor finish repair (or just leave the seam showing if it doesn't bother you).
  4. Assuming it's been loose for some time, there is potentially all kinds of crap in the glue joint that may prevent it from clamping down tight. I would remove it and clean is up first. This will also allow you to assess what the best glue is for the repair, depending on what was originally used.
    whero, Beej and Matt Liebenau like this.
  5. Thanks for the responses so far. I'm just back after a few days where I haven't had time to check TB.

    I was just going to try to slip some glue in the crack and seal it, but I totally see the sense in ripping the fretboard off totally and cleaning it up properly before gluing. While it's been in a case since I noticed the damage so, I hadn't thought about old, dry, loose glue, etc. I'll head to a hardware store this weekend and try to get the right adhesive, and be prepared to post before, during and after shots...
  6. Jon Clegg

    Jon Clegg Supporting Member

    Feb 9, 2015
    Northern Virginia
    While you're getting supplies... You'll need a couple of putty knives and a clothes iron. While it's already coming up, I'd use the iron to soften up the glue right where about to peel up the FB. With this one, I'd start where there's already a gap.
  7. dwizum


    Dec 21, 2018
    Titebond I is probably the best hardware store glue for the job. Don't get lulled into upgrade fever and assume II or III are better, they tend to come with problems for guitar work (creep and/or visible glue lines). You could also use epoxy if there's a good quality fresh epoxy at your hardware store (my local mom and pop store has cheapo 5 minute epoxy that's probably been sitting on the shelf for 5 years. About the worst possible choice).

    Once in a while there are metal or wood alignment pins between fretboards and necks to hold them in proper orientation. So be ready to hit something solid as you work the fretboard off. It's usually not a big deal since you can just sort of skirt the putty knife around it and pop it off anyways.

    Don't use the putty knives as levers, that will often just lead to denting the edges of the neck or fretboard. Instead just focus on pushing them through the glue. Having two can be helpful since you can leave one stuck in as a wedge to keep the gap open while you work the other one. Don't use anything too thick to wedge the board off, if the board gets hot while it's wedged or bent it will retain the bent shape.

    And this probably doesn't need to be said, but be careful of that spruce top! It'll be easy to dent it with the putty knife or even pull chunks of it out with the glue if you're not careful. When in doubt slow down and be gentle. Better to take an extra 10 minutes than rip the soundboard.

    Once it's off you can use mid grit sandpaper (100 or so) on a hard flat sanding block to clean up the existing glue as needed. Just be careful and keep things even, stop and check often so you're only removing glue and not getting into the wood. It will be helpful to mask off the spruce top with masking tape to keep it safe.

    When you get to gluing the board back on, use masking tape again to protect the soundboard and neck. Getting the alignment perfect will be the biggest challenge. If there were alignment pins, you can probably just re-use them. If there were not, you can consider using a cut off finish nail or toothpick as a hidden alignment pin, or just try your luck at lining things up by hand. What I like to do is clamp each end to lock the board in place, then wrap an old bicycle inner tube tightly around the neck/fretboard as a sort of improvised band clamp. The tube will be soft enough to not mar or crush the wood but it will hold it plenty tight enough to get a good tight seam.
    byacey and Beej like this.
  8. Also, in case it hasn’t been mentioned, score around the fretboard extension on the top to try and minimize or eliminate chipping the finish.
    dwizum likes this.
  9. Two or three Ty-Wrap ties work very well for aligning the fingerboard and neck during gluing. Once they are tightened up, they hold them in alignment when applying the clamps."+ty+wrap&qid=1598373466&sr=8-7
    5tring and dwizum like this.
  10. Arie X

    Arie X

    Oct 19, 2015
    Cimar acoustics are laminates so I wouldn't worry about damaging fine spruce. That being said, don't damage it. Laminate guitars are far harder to repair then solid wood ones. To do this decently you'll need to pull the fretboard. A hot iron is required over the extension to separate it from the top unless it's pretty much ready to fall off. Remove old glue by block sanding or scraping. If there are alignment pins see if they can be reused otherwise fire in a heavy staple on either end of the neck and cut them down to small points.

    When it's apart now would be a good time to asses the trussrod. It's likely a compression rod and would benefit from a tiny amount of anti-seize grease or equivalent on it's threads and between the nut and washer after you wire brush the threads nice and clean. If you can replace the nut and washer with correct, new pieces, that would be beneficial. Set it to neutral before re-gluing with the backlash adjusted finger tight towards backbow.

    Titiebond Original would be the glue of choice. Sisal rope or inner tube are ime, not the best clamping solutions. I prefer a 1/2 doz Bessey clamps and a heavy piece of maple for a fretboard caul for this work. Reason is, is that you can't see the glue squeeze out with inner-tube or rope nor can you clean it up when it's semi-cured either and it can trap moisture in the neck for a bit longer then I like. You need to see the smallest bead of glue coming out or you are potentially starving the joint. Too much glue on the other hand, can be a big mess once it's dried and can indicate that you may have clamped up too hard pushing the glue out of the joint. They do make special zip-tie clamps for this type of work. I suggest some tape over the nut slot to minimize clean-up when the glue dries.

    Wet glue is like liquid grease and alignment pins of any type are going to help out a ton. I like to use a strip of .0015 thick Kapton tape over the truss rod slot as a glue barrier. Clamping down the fretboard extension is important. You will need a decent clamp and two cauls -one for the fingerboard and one for inside the guitar. This will likely need to be trimmed, adjusted, etc... to clear the upper traverse graft for solid clamping pressure.

    Spot refinishing is going to be a-la-carte. You need to decide how far you want to go with this. I do highly suggest one or two practice runs with your tools and materials before the glue goes on. You don't want to be fumbling about with clamps etc.. with fresh glue in action. Keep the clamps on for 24 hours.
    Last edited: Aug 26, 2020
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