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  1. #1

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    Hey guys. I have a little project with an Epiphone LP. I has some cracking through the finish on the neck from the headstock to about the 4/5 fret. Its just a little beater guitar so I'm not worried about using it for some DIY learning. My intuition tells me I can just tape off the rest of the guitar and spray a few layers of some kind of clear coat on the neck.

    My question is this- Is this train of thought completely incorrect (is there a better way, in other words). If I'm on the right track, what kind of spray would you use? I'm assuming the guitar has a polyurethane coating- What would adhere and not interact negatively?

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  3. #2

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    Also, I ran it under black light and nothing showed up so I'm confident the crack doesn't do into the wood itself.

  4. #3

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    Personally checking is never worth fixing unless the finish is flaking off.

  5. #4

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    Its just rough enough on the hands to be annoying enough to want to do something about it. That's where I'm at with it.

  6. #5

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    You could try sanding it and buffing w out adding any finish to smooth it out.

  7. #6

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    Hmm. There's spidering though. I wonder if that might inadvertently chip off some shards. But that would be the easiest way. Any idea what grit would be ideal?

  8. #7
    Quote Originally Posted by BiscoDrew
    Hmm. There's spidering though. I wonder if that might inadvertently chip off some shards. But that would be the easiest way. Any idea what grit would be ideal?
    Poly is usually applied pretty thick in production guitars. It's most likely not going to chip off. If you start to pick at and remove poly patches, they're going to reveal tenacious spots where the poly adheres to the wood better than others. Sanding it off is a bad option because if your thought is to take it down to the wood, the moment a spot goes through to the wood it will remove wood a LOT faster than it will the surrounding finish. You'll wind up with serious divots and valleys where the wood disappears.
    As far as sanding it smooth, yeah that's the best option. Finishing sandpaper starts about 400, anything coarser than that is material removing grit and more work to get smooth. 400 or even finer truth be told, then maybe 800 will get you to a satin feeling neck. Polishing grits like 1000 and up will get you really smooth and if you make it up to the 2000 neighborhood, those are really fine grits that will begin to put a reflective surface on poly. You can get even finer than that will automotive polishing compounds and that gives you a really slick fast neck. You can get a decent wax, carnuba or butcher's wax type and that'll protect it just fine.
    Work with the finish that's on there, don't dwell on any localized area or you'll get an uneven surface you'll feel when the finish gets to a gloss.

    You can clear coat if you really want, do that before or instead of the above mentioned wax. I've had varying degrees of luck depending on what I used. After a spray coat, work from finer than 800 and work to what feels good to you.

    Have fun and good luck

  9. #8

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    Awesome! Thanks guys ^^^

  10. #9

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    So here's what we're dealing with.

    I'll post some after pics. Wish me luck : )Respraying finish cracks in beater guitar-neck1-jpgRespraying finish cracks in beater guitar-neck-2-jpgRespraying finish cracks in beater guitar-neck3-jpg

  11. #10

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    Yep. It flaked off.

    Its silky smooth otherwise. At this point I'm just gonna try the clear coat and sand it down to even. Lesson learned.

    The upload function is glitching out Ill try later to show what's going on.

  12. #11

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    Here
    Attached Images Attached Images Respraying finish cracks in beater guitar-win_20210401_23_17_12_pro-jpg 

  13. #12
    I've seen this very type of finish crack. I don't know about your black light but in my book, that's a sure sign of an underlying wood fracture; very fine, along the grain line, virtually undetectable to the untrained eye but absolutely there. It's the result of a shock trauma, a drop in the box or case where the headstock received in inertial impact (dropped) and the weight of the guitar was transmitted up the neck to its weakest point at the nut. This is the "almost" stage of the very well known Les Paul scarf joint failure that every repairman knows all so well. Something moved, something gave, look at the lay of the grain; it moved-the brittle poly finish did not=it cracked.
    I worked QC and repairs at Hoshino, or as you know it, Ibanez. In Bensalem, our crew checked, set up, and meticulously inspected EVERY Ibanez guitar that came into the USA from their factories throughout Asia. I saw a LOT of guitars, repaired a lot of slight imperfections that relegated many a guitar to the seconds and, in cases where structural damage from shipping caused what was deemed a compromised "broken" guitar, we did an outright reject and the guitar was destroyed and stripped for parts.
    This checking at the nut even at a much lesser degree, was grounds for the fastest outright rejection. Don't fool yourself, that wood is split along the grain/join line.

    Now I understand that's your beater guitar and you don't feel anything wiggling there, but...
    Fast forward to the repairman's bench. If I got this into a shop, I'd immobilize the neck in a jig and VERY and all so gradually apply a torqued pressure to the headstock. That join is designed to take that kind of pressure under normal use; you've got the tension of the strings pulling constantly of course. In applying this kind of pressure, the idea is to open it up ever so slightly and put some kind of glue in there. Cyano is deeply penetrating, but yellow wood glue under pressure is my first choice if I could open it up enough to wiggle it in there.

    Yes you've got some chips missing there. There are a few ways you can address that. Slowly building up the finish with a medium viscosity cyano based product, or clear finish applied by brush on slowly (masked off, built up, sanded back and leveled) or built up with repeated spray in the area. Make sure the area is thoroughly cleaned of any contact oils, oxidation or possible shmutzen before you even think about applying finish to the stabilized area.

    Now I'm sure you're going to get a lot of "That's fine. My guitar looks like that and after all your black light didn't show anything up" comments. It's a forum after all, but this is just my opinion based on your photos and decades of hands on lutherie and experience, my gut, and my best cautionary advice given I don't have the guitar in my hands to wiggle and prod into revealing the injury more fully.

    If you're unsure, take it to a GOOD luthier. I'm not talking the most convenient big box tech but if possible someone with luthier skills who can read the wood, open up and reveal the depth of the damage without making it worse and advise you from a fully informed perspective.

    It may very well be that there's enough integrity in there despite a simple crack, and it's possible that applying the cyano in filling the finish, it could penetrate along the edges. Who knows? This is arm chair remote guessing at best.
    Now you have information.

    Best of luck.

  14. #13

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    That was the an epically insightful post brother.

    But is the juice worth the squeeze to take it to someone? I'd say prohibitively so. That being said, I am more then willing to try out your suggested method. Is there anyway to torque the scarf joint without the proper tools? I have a vice and two hands and thats about it. I'll look into some Cyano today.

    Many thanks.

  15. #14

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    Do you think this would explain my tuning stability issues on this instrument? Its slight, but its there for sure.

  16. #15
    Quote Originally Posted by BiscoDrew
    Do you think this would explain my tuning stability issues on this instrument? Its slight, but its there for sure.
    That was one of my "I'm surprised you didn't mention..." points. I was going to say I'm surprised you haven't shown any tuning issues.
    Yeah see what anyone else says about this. I'm PM you. You can decide what course of action but I'll give you more detailed notes in a PM.

  17. #16

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    Please do. I'd appreciate it very much!

  18. #17

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    For the record, you were 100% correct. When I torque the headstock with a very minimal amount of pressure there is separation visible in the wood beneath where the poly chipped off. I wonder how much load that coat bears. Anyway, I'm glad I got down to bare wood now because otherwise I would have never known FOR SURE the extent of the damage. Until the headstock snapped right off that is.

    I am game to get some wood glue in there, clamp it, then deal with the finish touch up and coating by hand.
    I asked for a DIY learning experience- I guess I got it.

  19. #18

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    UPDATE

    So I gathered my tools and consulted with a professional. Basically I'm just going to inject the crack with titebond, clamp it up and let it cure. This will also be a great opportunity to re-glue the nut which is free floating at this point. As for the finish, I got some modeler's paint that matched and after the neck is done I'm going to touch up the areas where the finish has been sanded, match everything and then finally apply polyurethane high gloss to the affected areas with a brush. A little wet sand with very high grit paper 2000/3000 and some compound polish to finish.

    Hopefully it turns out okay for a beginner repair job. Keep in mind I'm passionate about learning how to do repairs myself and I have to start somewhere! If nothing else, now I have a couple clamps and wood glue in my toolbox.

    I'll post some pics later. Fingers crossed.

  20. #19

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    ** Also, I was instructed to add a little alcohol to the glue in order to reduce its viscosity and penetrate the wood better.

  21. #20
    When you're gluing, wiggle the two pieces as much as is reasonable to work the glue in as deep as it can go. If you can open it up enough to get a piece of thin plastic in there (I always grab a clean food box made from clear plastic, cut out a little applicator) and if that can get in between and inside a crack while it's under pressure, then the deeper you can get the glue in there the better.
    I'll keep the neck clamped down (wrap it in a rag so you don't mar the finish with clamp or vice edges. In a vice, I'll make a caul to hold the neck within.)
    On the headstock, you might clamp a piece of wood to give you leverage. This will give you more control to gently open the breach. It also gives you an arm to wiggle that half of the neck as you work the glue in.

    Do yourself a favour and take the tension off the truss rod before you begin.

    I do this kind of thing second nature so I can't remember all the little steps I take for granted, so before you begin, have all your materials together, damp rag for spot clean up (it's easier to wipe up post clamping slop about 30 minutes after clamping before you have to really remove it dry)...that kind of stuff.

    There's really no need to glue down the nut. That's a factory thing. I keep mine in place by the string tension, and if I ever need to make adjustments, go for a lower action, adjust for fret work, etc, the nut can just pop out and be worked.

    Do a dry run. So all your steps are clear to you. Then go to it! Good luck

  22. #21

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    Thanks!

    How much tension are we talking? I never considered adjusting the truss rod, presumably to allow even more play in the wood as I'm putting in the glue.

  23. #22
    Quote Originally Posted by BiscoDrew
    Thanks!

    How much tension are we talking? I never considered adjusting the truss rod, presumably to allow even more play in the wood as I'm putting in the glue.
    Take the tension out til the rod is slack. This is because the rod's purpose is to hold the neck in a natural position and counteract the pull of the strings pulling it out of true by pulling the other way. No strings, that rod is going to pull the neck the other way, right? And you glue that neck back in place while it thinks that overbowed neck is normal, right?
    No string pull, no truss rod counter pull. Let it relax and then go about restoring the neck to where it wants to be. Straight as the wood was intended.
    Hopefully when the neck is totally set and dried, the strings will exert their normal pull and the truss rod will bring it back. Just like you glued it.

    I'm curious, just when DID you notice the damage?
    Public service announcement to all the lurkers out there reading this very interesting thread: If you EVER notice finish crazing radiating from the nut and following the grain, de-tune the guitar IMMEDIATELY and if you're up for it, take tension out of the rod. Then see your knowledgable luthier for further action.
    A stressed and cracked neck with broken micro fibers in the grain will acquire a memory and in the worst cases the surfaces will oxidize and compromise any glue join. Fast action makes for a good clean repair.

    I was at a concert once and the guitarist's strap gave way as he was putting it on. It swung off him and lightly hit the floor. He thought it was fine, it looked fine. But I saw the way it had hit and I yelled up from the audience "DON'T MOVE!" and he froze. I jumped onto the stage and began untuning his guitar, and only when I'd gotten the tension off did he see the crack line along the scarf join.
    I missed the concert. I took it to the shop immediately. Took the rod to slack and jigged it up through the night, clamped it up and sent him photos at 1 in the morning of the guitar in clamps and jigs. 24 hours later before the wood even registered the trauma, it was strung up and played better than it ever had. Fast action makes for a clean repair. By the way that was a Gibson 339.

  24. #23

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    Interesting story^^^

    I noticed it immediately- I bought it dirt cheap just that way. I was hoping for the best but prepared for the worst. Now its become an opportunity to learn something. So a win all around. And unless I Magilla Gorilla the headstock off the guitar, I have confidence that whatever the end result is, it will be better then what it was. And, like I said, if it turns out to be a total failure I'm only out a couple bucks for the guitar itself and the associated tools. Having the opportunity to do some work on a guitar in this way is not one that comes around often as I historically would never (except in this case) buy a broken guitar in the first place.

  25. #24

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    So here's stage one. The truss has no slack in it and the tailpiece/strings are off. I'm letting the neck relax for a bit before I commence to wiggling. Here's some not so high quality pictures of the offending neck. I'm hoping the fact that with little opposing pressure from the string side of things that the fracture is still (to my untrained eyes) rather slight- I expected a lot more play.

    Respraying finish cracks in beater guitar-neck4-jpgRespraying finish cracks in beater guitar-neck5-jpgRespraying finish cracks in beater guitar-neck-6-jpgRespraying finish cracks in beater guitar-neck7-jpg

  26. #25

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    Maybe I should have spent my money on a phone upgrade