what to use to fill control cavity

Discussion in 'The Custom Shop' started by chrislouden, Oct 3, 2008.

  1. chrislouden

    chrislouden Junior Member

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    I have a double cut Gibson that I am converting to lefty. In moving everything to the other side I duplicated the control cavity in reverse. I now need to cover up the original control cavity and volume/tone holes. What is a god material to use.

    I keep hearing "marine tex" and NOT to use bondo.

    I have used bondo in the past to repair damage to mdf panels used for arcade cabinets. I'm pretty good with it and feel pretty comfortable with it. I know I can shape it as needed.

    I tried to use some so-so quality wood fill in combination with some dowels to plug the pot holes. It didn't work out so well and I have remove it. It shrunk a little but never got as hard as I know bondo can get. Wood fill is not meant to be used to fill large holes.
     
  2. FLICKOFLASH

    FLICKOFLASH V.I.P. Member

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    try wood plug
     
  3. chrislouden

    chrislouden Junior Member

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    um... wood plug = dowel

    or are you referring to a specific product named wood plug?
     
  4. BCRGreg

    BCRGreg V.I.P. Member

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    Fill holes in mahogany with......


    MAHOGANY.


    Same with Maple.
     
  5. Dino

    Dino Senior Member

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    You don't have to fill the cavity ...
    You can just dowel the control holes call it a "chambered" double cut. :)
    It won't interfere with your conversion and may even serve as a cavity for active electronics or other ideas in the future.

    If you don't like that idea and really want to fill the cavity, I suggest making a template and filling the cavity with a solid piece of wood, cut and shaped to fit. Then you can fill the seams with Marine Tex.

    I've used both Bondo and Marine Tex ...
    Bondo is a filler and it does shrink which will eventually show lines exposing your "modification".

    Marine Tex is an epoxy type adhesive as well as a filler that will not shrink.
    It can be filed, sanded, and drilled through if need be.
    It's good stuff. :)
     
  6. chrislouden

    chrislouden Junior Member

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    ok... How?

    Do i make a mold of the cavity? Like put clay in it to dry, take it out and cut a piece of mahogany just like it?

    Or do I make the cavity a hole (clean though) and cut a piece to fit the hole and sand smoother on each side?

    This is a junior style LP, flat on top/bottom.
     
  7. Dino

    Dino Senior Member

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    Again ... make a template.
    Then trace it out on wood the same thickness as your cavity.
    Cut, glue in place, and fill.

    Here's one way you can make a template ...
    This is how I make templates for making my own control cavity covers.
    The picture is pretty self-explanatory. ;)

    [​IMG]
     
  8. randelli

    randelli Senior Member

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    AMAZING!!!

    I have worked with wood for 20+ years and I still love the old "ah-ha!" moment. This is the most ingeneous thing I have seen in a long time. It is incredible how the most simple technique will solve such a complex problem.

    I have often thought about making a new coverplate and dreaded the shape/fit/shape/fit/throw away/start over///////

    Good Job Dino!:applause::applause::applause:
     
  9. chrislouden

    chrislouden Junior Member

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    Here is what I'm working with

    Things to note.
    1) The original jack hole was drilled out due to damage.
    2) I previously placed dowels in the holes and filled the original cavity with wood fill that did not work out. I have removed 99% of that wood fill but there is some more clean up remaining.
    3) The original cavity is not completely open. In between the pots and jack the wood is higher. For strength I presume. Giving each its own pocket.
    4) The new cavity is ready to go. It is black as I already painted the guitar once but was unhappy so i re-stripped it but did't strip it. I used the original cover to design/create.
    5) I'm not opposed to having a "chambered" guitar. So simply putting the dowels back in to cover it from the front would be fine. I could put the original cover back on and make a new cover for the new cavity. I would rather make it look as if the original cavity/knobs never existed.

    6) I made the pickup cavity deeper to accommodate a H-90 pickup. Although I'm considering changing it again and putting a SD SH-4 (JB)

    Should i route out the original cavity so that it is open like the new one? then shape a piece of mohog to fit in it?
     

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  10. Dino

    Dino Senior Member

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    Despite everything noted above, I still see no reason why it can't be done.
    Just route a cleaner cavity and go from there.

    Better yet, cut a block of wood with the proper thickness (same measurement as the depth you will be routing), and use THAT shape to trace out the new routing pattern over the existing cavity.
    Once you're done routing, you'll have a block that'll fit the cavity perfect! :dude:
     
  11. Dino

    Dino Senior Member

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    Thanks! :)
    I use the same method to make pickup shims too.
    This raises the cavity and allows pickups to be mounted directly to the wood.

    [​IMG]

    Before:
    [​IMG]

    After:
    [​IMG]
     
  12. chrislouden

    chrislouden Junior Member

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    Cool. Thanks. I think I can manage that.
     
  13. FLICKOFLASH

    FLICKOFLASH V.I.P. Member

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    make a new body much easier
     

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