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Gluing down an exotic top

Discussion in 'Luthier's Corner' started by Basschair, May 10, 2005.


  1. Basschair

    Basschair .............. Staff Member Supporting Member

    Feb 5, 2004
    Stockton, Ca
    Hi folks,

    The body wood of my first project is expected to arrive today (tomorrow at the latest). The body is bubinga with a thin slice of wenge and a figured bubinga top...the figured top is coming in two pieces. Here's what I'm wondering:

    First, if the body comes in two pieces, I'll know how to glue it, and have the clamps to do it with. When gluing the top on, I assumed that clamp pressure must be applied vertically, pressing the top down onto the body. In order to get a tight seem where the two piece meet along the centerline, should I also use clamps to apply horizontal pressure? If so, just how much pressure should be applied?

    Also, are bubinga/wenge/purpleheart considered "oily" woods that must be approached differently with regards to glue? I'll be using Original Titebond.

    If anyone has pics of the process they go through to clamp down a project (gluing top to body), I'd definitely appreciate it!

    Thanks!

    paul
     
  2. teej

    teej

    Aug 19, 2004
    Sheffield, AL 35660
    I think what most do is glue the two top pieces together (at the center line), let it dry, and then glue it to the body, which should also be glued together at this point.
     
  3. Basschair

    Basschair .............. Staff Member Supporting Member

    Feb 5, 2004
    Stockton, Ca
    Thanks for the post.

    So, is this the predominant approach for others as well? How do you ensure that the two pieces stay on a flat plane with respect to eachother?

    Also, when applying glue, does anyone use this approach: small foam paint roller to spread an even film of glue on the core top and the exotic bottom, clamp together, and then quickly wipe up any spillage?
     
  4. I've used a foam roller to do this. The only thing that I find is that there is a fair amount of glue wasted if you're only gluing up something fairly small. I personally prefer to spray some glue on and then spread it around with some thin wood scraps for most stuff.
     
  5. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Maryland
    Owner: FBB Bass Works
    I'd laminate the halves first, then run them over the jointer, then edge glue them together into the body blank.
     
  6. yes, of the two methods discussed here, this is the one I prefer. It's pretty difficult to align the center lines if you glue the top and core first. It's especially more difficult if you are using an accept stripe/veneer.
     
  7. Basschair

    Basschair .............. Staff Member Supporting Member

    Feb 5, 2004
    Stockton, Ca
    Is this the approach you would take with a top set from Gallery Hardwoods? I was under the impression that these tops would need a little roughing with 150 grit and then would be ready to glue? Of course, it's my first time with all of this, so I'm not certain of anything. I'd rather ask you all with the experience and look stupid here than try doing it blind and creating a Frankenstein-looking thing :eek:
     
  8. Skorzen

    Skorzen

    Mar 15, 2002
    Springfield MA
    When gluing the top on I have used both methodes, and I feel the jury is still out as to which is better. Also when gluing a thick piece I like to place the thin piece on a flat surface and glue thing thicker piece on top of that. This allows you to use the thicker part of the body as a caul to spread the clamping pressure more evenly.
     
  9. Basschair

    Basschair .............. Staff Member Supporting Member

    Feb 5, 2004
    Stockton, Ca
    This makes sense, but you'd do this when the thin piece is in one piece (either one solid piece, or already glued together), yes? That way, you wouldn't need to worry about glue cleanup between the two halves of the top, but rather just around the sides?
     
  10. gyancey

    gyancey

    Mar 25, 2002
    Austin, TX
    150 grit is too rough for glueup. Technically on a nonstressed joint like the top it would be OK but wood glue (i.e. Titebond) works best with planed or scraped surfaces. Scrapers are really easy to use and with the sharpening tool from Stew-Mac its almost brainless now.
     
  11. Tim__x

    Tim__x

    Aug 13, 2002
    Alberta, Canada
  12. Basschair

    Basschair .............. Staff Member Supporting Member

    Feb 5, 2004
    Stockton, Ca
    I knew I remembered that from somewhere ;) . I actually picked up some Lie Nielsen scrapers, and was just starting with them on scrap hardwood pieces. I've only seen the Veritas burnisher for scrapers. I guess I should check the stewmac website again.
     
  13. Suburban

    Suburban

    Jan 15, 2001
    lower mid Sweden
    Old carpentry rule:
    Each glue joint needs to be taken care of.
    Each glue joint you add to one task adds more attention.

    This is the reason why the majority do one joint at the time.
    I've tried a lot of mutijointing, based on cockyness, with the result you can expect from a cocky little...well, insert whatever.

    One joint at the time, clean it up and do the next. That's my recommendation, worth 1.5 cents, or something.
     
  14. Basschair

    Basschair .............. Staff Member Supporting Member

    Feb 5, 2004
    Stockton, Ca
    So, glue the top pieces together (first joint), followed by gluing the top down to the core. When gluing the top pieces together, is there much need to apply any vertical pressure in order to ensure the pieces stay on an even plane with eachother?
     
  15. Suburban

    Suburban

    Jan 15, 2001
    lower mid Sweden
    Some, yes...
    The pic is stolen from Jake M. A pretty neat arrangement, IMO.
    He seems to use a table router as the base, and the fence of it as clmaping devise. Keeps things very straight, I'd say.

    And you will probably need to assure planity before gluing it on the body.
     

    Attached Files:

  16. Skorzen

    Skorzen

    Mar 15, 2002
    Springfield MA
    As Suburban poasted some pressure is good. here is a pic of a wenge laminate being glued. The 18" sub driver is the secret to getting that really sweet bass sound :D :eyebrow: :ninja:
     

    Attached Files:

  17. Basschair

    Basschair .............. Staff Member Supporting Member

    Feb 5, 2004
    Stockton, Ca
    In the pic you posted, the top is being glued together directly on a table. What type of material is that surface? Formica? I was told that melamine might work as a fairly non-stick glue table top, and UHMW sheets are a little pricey. I ask because I'm wondering about the glue adhering to the table top. Also, the thin strip of stuff (wax paper?) between the jointing plane and the wood...?

    How about it folks: melamine or UHMW for a non-stick surface to glue upon? For the UHMW, I'm thinking the 3" wide strips, 22" long, with the adhesive backing stuck to a segment of hard fiberboard which can be a mobile table top and is clampable.
     
  18. nateo

    nateo Schubie Fan #1

    Mar 2, 2003
    Ottawa, Ontario
    About the easiest way to make a good surface to glue on (according to my infinite wisdom) is to take one of your bench tools (i.e. table saw or router table) and lay down a sheet of wax paper or even saran wrap. The table is pretty much guaranteed to be level and the wax paper or saran wrap will prevent the glue from sticking to it.

    If you haven't got a flat topped bench tool then look around for a chunk of G1S plywood or an old counter top (I've got a few in my shop for just such an eventuality). They should perform the same service despite being less rigid.

    We successfully used saran wrap when epoxying down some carbon fibre rods. After the epoxy was dry, the wrap pulled right off without any hint of trouble.

    -Nate
     
  19. gyancey

    gyancey

    Mar 25, 2002
    Austin, TX
    I have an MDF board that I routed a 1/4" trench in so the glue drips into that which I periodically clean out with a chisel. Or just use the wax paper.
     
  20. Basschair

    Basschair .............. Staff Member Supporting Member

    Feb 5, 2004
    Stockton, Ca
    Sweet: that's exactly what I was looking for. So something like Titebond doesn't adhere significantly to wax paper?

    BTW: I dig your site and work examples, Greg!