Is this a crack in the wood or just the surface?

Discussion in 'Luthier's Corner' started by Steve D, Feb 8, 2020.

  1. Steve D

    Steve D Well-Known Member

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    I bought a "vintage" PRS (it's 30 years old which is old for PRS) for a seemingly great price and I noticed it had a big scratch on the back. I could feel that it went pretty deep into the surface but I did't see any evidence that it went into the wood. I figured it was cutting across the grain at the thickest part of the guitar and it didn't make sense for wood to crack that way. I did open the trem cavity, as it seemed to radiate from the screw hole there and I didn't see any cracks so I figured I was good.

    However the wood inside the cavity was dark and the lighting where I bought it was terrible so I think I missed something. Looking at photos taken in better light now I can see that there is a crack into the wood at least at the screw hole, and on the other side of the screw hole (going down into the inside of the cavity I can see a crack maybe an inch deep (See photo, hard to see but I drew a circle around it). But on the side going to the back of the guitar I don't see a crack inside the screw hole.

    I'm wondering if any expert luthiers here have an opinion on whether this is a wood crack going across the back of the guitar or not. I figure "who knows more about body cracks that guys who work on SGs?" :smile:
     

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  2. donepearce

    donepearce Well-Known Member

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    Well, it looks like a crack , but as you say the direction makes no sense. Cracks just won't propagate across grain that way. I think you need to get it under a powerful lens for more information.
     
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  3. papagayo

    papagayo Well-Known Member

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    I think it' s a crack, with slow époxy it' s possible to stop damage.
     
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  4. donepearce

    donepearce Well-Known Member

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    I think that needs to be Plan B.
     
  5. Steve D

    Steve D Well-Known Member

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    If it's a crack, it's a hairline and it's across the grain which is nutty. Pus it's across the thicked part of the wood, not the thinnest which as an SG guy used to seeing cracks at the horns, at between control panel and guitar edge, at the neck pocket, etc also seems very counterintuitive. It doesn't move at all, I can't see through the hairline crack in the finish down to wood (though I can fit the tip of a fingernail into it, it's wide enough for that at least in the surface finish. Also recall that there's a maple cap on this and is in perfect shape with no signs of trauma at all, and it also acts as a brace of sorts to prevent the mahgany back from flexing.

    Hard for me to see how it will catastrophically open up suddenly so my first order of business is to follow the Hippocratic oath: First, do no harm. To get epoxy or super glue into it, it would have to be widened or drilled into I suppose, and I don't see an urgent need to do something that dramatic ... yet. But if it moves at all things change.

    First step will be to look at it through a magnifying jewelry loupe or something like that, see if there's anything that makes it looks better / worse.
     
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  6. S.Ustain

    S.Ustain Active Member

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    Let's all admit that the photos do not allow us to tell if the crack goes into the wood. The rest is speculation, which is less than worthless. That's a remarkably thick finish for a PRS, so it could well be just a finish crack. But if the instrument took a blow, or some other force was exerted, mahogany can crack in funny ways. In the flesh, it would be easy to judge what we're dealing with. In pictures, it's impossible to be sure. In any case, I'd leave it alone.
     
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  7. PixMix

    PixMix Well-Known Member

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    I would suggest using imgur for photo hosting. Upload high res images, and then select "original" (user "Sizes") before copying the link (BBCode). It's really impossible to tell from the images you provided.



    [​IMG]
     
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  8. donepearce

    donepearce Well-Known Member

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  9. Steve D

    Steve D Well-Known Member

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    That picture of a snickers bar has convinced me that they know their stuff. I'll reach out tomorrow. :smile:
     
  10. Steve D

    Steve D Well-Known Member

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    I'm not sure I can get a good enough photo because even under a magnifying glass (albeit a not very powerful one) I can't see much on the body side. But I will use my real camera with the optical zoom instead of my phone to try to take a really good shot and see if I can see anything better than a white line. If I do, I'll try posting it as you suggest.

    One thing I'll do though is stop experimenting with dive bombing the tremolo for a while, jst to stay on the safe side.
     
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  11. papagayo

    papagayo Well-Known Member

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  12. Steve D

    Steve D Well-Known Member

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    Let's assume it's a crack across the grain that starts at the trem cover screw hole and ends right where they belly cut starts. Again, it's a PRS so the mahogany back is glued to a maple top and that has no signs of any trauma at all. Do you think it's best to just do nothing and keep an eye on it to see if it spreads or should I try to get some sort of fix put in place proactively? I lean towards just leaving it alone, I'm not throwing it in the back of vans on tour or anything, I just play in my home music room pretty much. Thoughts?
     
  13. Chuteboxehero

    Chuteboxehero Active Member

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    I'd leave it alone but keep an eye on it. If it starts to spread you can find thin super glue with the tiny tip on it... It'll wick right into the split and it'll be pretty solid after that. I had an '87ish Strat that had the first version the 2 post trem that didn't have threaded inserts. Just 2 bolts right into the wood. By the next year they fixed that design. This one had pulled a whole chunk of wood out but a little bit of super glue and it never budged again.
    [​IMG]
     
  14. jtees4

    jtees4 Well-Known Member

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    Looking at your picture inside the cavily, it appears that if the crack was indeed in the wood....you should be able to see evidence of it INSIDE that screw hole that it would have to go through. Inside the screw hole is bare wood, not finished. I hope that makes sense. Good luck.
     

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