Tearing in grain when sanding

Discussion in 'Tele-Technical' started by Astralis, Jan 26, 2020.

  1. Astralis

    Astralis TDPRI Member

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    Hi, I recently posted about putting together a parts caster. Today I was sanding a contour into the body and after taking some material out the grain became like this, I am not sure how to describe it so I couldn't get any results when searching
    [​IMG]

    It appears to be hollow inside, I can't say for sure if it is an air pocket or it is chambered or what. I am not sure of the specifics of this body as I bought it used, but it is by "Holy Grail Guitars Co.".

    I'm not sure of what action to take here, two things i have thought of is just 1. filling it with sawdust and superglue, or 2. Using wood filler, and then just a quick final sanding to finish it off and go no further. Could anyone else give me some pointers or possible fixes for this?
     
  2. hopdybob

    hopdybob Tele-Afflicted

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    do i see it wrong that there is some kind off sealer on the body?
    if you go solid color than i would fill it with sawdust and wood glue, and use a primer after that.
     
  3. telepraise

    telepraise Tele-Holic

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    Looks to be a pitch pocket. I would mask to it and inject it with superglue until it won't take any more. Then grain-fill the entire body. Looks like you might want to use a firmer sanding block (or a card scraper) to keep the softer parts flush with the ring wood of the grain. And make sure to sand out all your file marks and coarse grit lines before proceeding to the next finer grit.
     
  4. Astralis

    Astralis TDPRI Member

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    Hi, thank you for the idea, I guess i will have to look for a syringe to fit into the hole. It appears to be very small as I can shine a torch into it and it still appears dark
     
  5. Blue Bill

    Blue Bill Poster Extraordinaire

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    I think telepraise got it right. Weird that it's so inky black. If you are using a clear finish, you may want to consider stuffing it with filler putty, so it won't be so noticeable. Wet the wood with water or naptha to get an idea of what color you need to match the finished wood. Warning: Some putty can leach oils into the area surrounding the filled area, resulting in a blotchy effect, especially if you are staining the wood. Stain it first, then match the color; the putty will not take stain the same as the wood. Try it out on some scraps, or inside the neck pocket first.
     
  6. GuitLoop

    GuitLoop Tele-Meister

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    Wouldn't sanding dust mixed with wood glue be a better match than just super glue?
     
  7. Astralis

    Astralis TDPRI Member

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    Well I finally got my hands on some filler this morning. Tried filling it a bunch of times with wood fillers slightly diluted with water but they filler never got far into the split even if I tried to push it in, and each time sanding it back the gap would widen, tried sticking a needle in and it appears to go much deeper than I originally thought.

    I tried superglueing a portion of it, I don't have a syringe to apply it and left quite an ugly result but it seems to work well, it hardened much harder than wood.

    The remainder of the crack I thought I would apply filler again and leave it to dry completely to see if theres a different result, but it's now a couple hours later and I can see the line forming again as the filler contracts in. I will try sanding it down again tomorrow

    It's really frustrating and I can't seem to get the filler to enter the crack and firm up properly to sand it down smooth. I thought of widening the hole before applying some wood glue and clamping it back down but I don't want to risk taking off a chunk.

    Luckily it's on the back of the guitar, I think I might just get it as shallow as I can and continue tru oiling the guitar, and see if I can fill up the surface while applying coats of tru oil.
     
    GuitLoop likes this.
  8. Telecentric

    Telecentric Tele-Meister

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    Syringes work best for pushing glue in and air out of tight spaces like that. You can get them and appropriate Luer Lock applicator tips cheap and easy here (click on the syringes, droppers and pipettes link)
     
  9. eallen

    eallen Tele-Afflicted Silver Supporter

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    Pitch pockets are a common occurence in some woods. I typically start with thin CA to seal it deep and followed by thick or medium to fill it on the surface. If I have a piece of wood with a lot of them I will heat the piece of wood and warm epoxy bottles such as Z-Poxy and spatula it on. The heat allow it to run deep into any pockets.

    Pitch pockets don't effect structural integrity as they are not cracks in the wood but just pockets of sap.

    Here's and example of one of my builds of cherry where I used clear to fill the many pockets at streaksto allowed the character of the wood to show thru. [​IMG]

    Eric
     
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