Contour 'drop' of top laminates

Discussion in 'Luthier's Corner' started by Tommy Gunz, Oct 21, 2004.

  1. I have a feeling that this is some sort of trade secret, but I'll ask anyway :) , how do you bend and glue a thin top laminate so it follows the forearm contour of the body? Also, is it necessary to oversize the laminate before final shaping of the body?
  2. I haven't done this on a bass yet but I've studied lots of bending techniques and there's several approaches from cold bending by brute force (you need thinner wood) to heating and bending if you've got the tools, time, and skill. I think something in the middle might be best. By that I mean, perhaps some prebending by soaking the corner of the top in water, clamping until dry to get the bend started then finishing the bend when you clamp it up on the body. If the top were thin enough, I would just clamp using flexible 3/8" thick x 1" wide strips of poplar clamped over the area to bend. You would clamp them solid on the far side of the body, letting a long portion hang over the forearm contour, then clamp the other ends down with the veneer under them. I'd probably use 3 of these strips and 6 total clamps for the job.
  3. Scott French

    Scott French Dude Supporting Member

    May 12, 2004
    Grass Valley, CA
    I've seen this done with a vacuuuuum bag and it seems like the best/easiest way if you are working with thin enough woods. Not many people would put down the money for one of those unless they are doing a lot of glue work so maybe that is a trade secret type of idea.
  4. Informative as usual, thanks Hambone.
    I have a 1/8" ziricote that I want to try, hopefully it'll turn out ok.

    That vacuum bag techique, I can't even conceive an idea of how it might work, care to enlighten us?
  5. tjclem

    tjclem Supporting Member Commercial User

    Jun 6, 2004
    Central Florida
    Owner and builder Clementbass
  6. budman

    budman Commercial User

    Oct 7, 2004
    Houston, TX
    Formerly the owner/builder of LeCompte Electric Bass
  7. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Owner: FBB Bass Works
    I might think you would want to pre-bend the ziricote with heat or steam. It seems like it might be a little too stiff/brittle to bend without a little help.

    You'll do best if you take time to make your forearm cut have as true a surface as possible but with a gradual slope where the cutaway "breaks" from the top. I would want to do the forearm cut with an edge/belt sander if possible. Second best would probably be a hand plane and hand sanding to smooth the break.
  8. Suburban


    Jan 15, 2001
    lower mid Sweden
    Pre-bend will help a lot. Then the good old sandbag may help: spray your laminate with water, put it in place (with the glue of course) and put a rather heavy and quite warm sandbag on top of it.

    Sort of a 'stone age vacuum bag'.
  9. tjclem

    tjclem Supporting Member Commercial User

    Jun 6, 2004
    Central Florida
    Owner and builder Clementbass
    I like the sandbag idea very good.
  10. FBB is onto a critical detail here...getting the foundation for the top laminate perfectly flat before gluing.

    I've found that making a perfectly flat plane across the forearm contour as it bends over the front of the guitar is difficult with most tools that aren't at least as wide as the contour face itself. I've taken to using my 18" thickness sander to make this contour so that it is nice and flat.
  11. As I was planning the steps on actually doing this with my current project, I also realized that I couldn't come up with a good way to round the edge of the forearm contour with the router. Do you think it'll have to be done by hand? But it seems a bit difficult to try keeping the same radius the same as the rest of the body edge that's done by a router.