Continuous wood backplate

Discussion in 'Luthier's Corner' started by Joe Gress, Feb 11, 2006.

  1. Joe Gress

    Joe Gress

    Dec 22, 2005
    Pueblo, CO
    How do I go about making a wood back plate that is built from the original body peice? Will it still be sturdy enough put screws in it?
  2. Hookus


    Oct 2, 2005
    Austin, TX
    Here is how I do it:

    1. Use a 1/4" thick laminated back.

    2. Cut the backplate out on a scroll saw before glueing it to th ceter part of the body.

    3. Rout the cavity with a pattern bit, using a bearing about 1/8 to 1/4 larger than the bit, this will give you a continuous lip.

    4. Drill holes with a coutersink bit, just don't overtighten, crackit, and you are hosed.
  3. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    Although it's not the usual practice, you might consider using some kind of screw other than a flat head or oval head. Both of these have cone-shaped undersides, that sit into a countersink, as has been noted. When you overtighten these, you are forcing a wedge down to split the wood. If you find something you like with a flat underside, and counterbore it instead of countersinking it, you avoid this possibility.
  4. Joe Gress

    Joe Gress

    Dec 22, 2005
    Pueblo, CO
    Thanks Again. Another Question though. If I use a flat undersided screw, do you think that I could go between 1/8 and 1/4 Inch thick for the Back?
  5. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    All depends on what you find in screws. I'd want at least 1/16-1/8" of wood remaining after counterboring, depending on the wood.
  6. teej


    Aug 19, 2004
    Sheffield, AL 35660
    Can this be done with an instrument without a back?
  7. ehque


    Jan 8, 2006
    you could bandsaw it in 3 pieces, creating a front, middle, and back, then use the above method to cut out the back plate. haha. thats the only way i see it working, really.
  8. Suburban


    Jan 15, 2001
    lower mid Sweden
    Yes, if there is a top. But it will demand some skill, and some weird attaching techniques.

    Basically, you rout out the electronics compartment from the front, and when done, you do the cutting of the hatch. You will have to do that at an angle, of course, which leaves you with a countersunk hatch. If you are really skilled, it might even look OK.

    I'll leave the hatch attachment to your imagination, but I assure you, it can be done:D
  9. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    Take a look at a Pedulla (definitely the MVP/Buzz, and also the Thunderbass, but I think not the Rapture). On the thru necks, even on ones without tops, he does this: take the treble body wing before gluing. Make a horizontal cut across the wing, to 1/3 depth of the wing, from the back. Then run it through a bandsaw from the butt of the guitar up to the horizontal cut, at that same 1/3 depth. Then do the cavity hollowing in the body, and also some in the cover.


    I'm not sure how he presently makes up for the loss of thickness from the kerf of the bandsaw cut; it could be that he thicknesses it after bandsawing, cavity creation, and screwing it back together. On my very old Pedulla, he didn't do this, but rather put an ebony (or other black wood) veneer layer onto the cut surfaces to make up the thickness.