New 4 String NT with full top and bottom cover build

Discussion in 'Luthier's Corner' started by mikebpeters, Feb 3, 2012.

  1. mikebpeters


    Aug 29, 2011
    NS, Canada
    This is my second build, parallelling but lagging my first as I work through each step. While my first is a bolt on, this one will be a neck through.

    The major pieces are now rough cut and sitting in their proposed sandwich to let me digest for a bit and make sure I really like it before putting more effort into dimensioning and glueing, and and and

    the neck will have a maple veneer piece in the middle bounded by purple heart, then by bird's eye maple, then with a bubinga outside (no disappearing lams)

    The body is curly redwood top and bottom with a anigre/bubinga/anigre accent stripe (top and bottom) and basswood core.

    I have a bubinga fingerboard for it that I may or may not light with LEDs haven't decided yet and it will have all fender style hardware.

    here is what it looks like in the roughest of terms.

    Attached Files:

  2. mikebpeters


    Aug 29, 2011
    NS, Canada
    well, I got the neck lam pieces all cleaned up and glued. Hopefully tomorrow the glue will be dry enough to clean up the neck and get it ready for the next few steps.

  3. mikebpeters


    Aug 29, 2011
    NS, Canada
    I got the neck all cleaned up and sized, and I got the wing cores sized too.


    Its almost starting to look like a bass



    Of course I have to stack 'stuff' on it to make it look even better


    Here are the two necks I have made side by side. Of course they both still have a lot of work to go to make them real necks, but hey, you have to start somewhere.

  4. mikebpeters


    Aug 29, 2011
    NS, Canada
    I have read that 3 is the perfect number when glueing together veneers but as this was my first time trying this particular feat I clearly misunderstood or mis executed somethinng.

    I put together some clamping cauls. I cut 2x10s into 2 foot lengths, glued them together and then ran them through the thicknessing sander to make nice sturdy clamping cauls.

    I then laid down wax paper, my first lam (anigre), spread titebond (perhaps too much?) laid down a bubinga veneer, more glue, then another anigre.

    I left it clamped for a day (too long?)

    This was all supposed to be an accent layer between body and top.

    Here is what it looks like sitting on the cauls.


    Here is a closeup


    Will this flatten on its own as drys further

    did I use too much glue, not enough pressure, too long in clamps, wrong glue?

    can't get there from here?

    Any advice would be appreciated.
  5. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    It looks like there was no clamping pressure at all, and in fact some gap at the center, with pressure only at the edges.

    I'm guessing you'd like to know not just a solution, but also the cause of the problem. How flat are your cauls - are they cupped on the working surface? Can you describe your clamping setup? Do you have a photo, or can you mock it up again and take a photo?
  6. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Owner: FBB Bass Works
    it's not going to flatten out on its own. you may be able to flatten it with an iron and a veneer hammer. problems are probably due to moisture introduced by Titebond but hard to tell without seeing how you executed the press and what the veneers looked like prior to glue-up.

    if you have not read a book on veneering, i do recommend seeing if there is anything at the library. working with veneer is different enough from the rest of the woodworking of making a bass where it's worthwhile.
  7. mikebpeters


    Aug 29, 2011
    NS, Canada
    thanks, I'll do that (read much more specifically on veneering)

    As to my clamping set up.

    I took a 2x10 and cut it in 2 foot lengths. Then I glued the pieces side by side to make two approximately 2 foot square pieces 1 1/2 inches thick.


    I took these and ran them through a planer a number of times to ensure that there was no cupping or anything.

    As to the gluing itself, I laid a layer of wax paper, anigre, glue, bubinga, glue, anigre, wax paper, then put the top caul on and then clamped around the edges (as far in as my clamps would reach) with about 15 or so clamps.

    Most of my clamps are tied up gluing a new neck together, so this one clamp is representative of the 15 or so that I used


    The veneers were flat prior to gluing, or just slightly wavy. I will take a picture of that too. In this case what appears to be wave is just grain - almost a shame to only use the edge of veneers like this.


    I'm not willing to put a ton of effort into salvaging this layup, but I do want to make sure that I don't repeat whatever mistake(s) I made the first time around.

    Edited with pics

    Meanwhile I will read specifically on veneering and not just gluing.
  8. To reach further in than the clamps would be able to I place a piece of hardwood (neck blank size e.g.) over it perpendicular to the cauls and clamp that down. This creates pressure in the center too. Looks like, in your case, clamping it around the edges made the boards slightly give in the center.

    The wrinkles look like wet wax paper, so it looks (not sure though) like if the cauls weren't pressed together fully in the center and the veneer followed the wet wax paper that was able to move.

    To illustrate my explanation, this is how I do it:


    The hardwood bar has enough lateral stiffness, so if used this way, it pressed against the center as much as the clamps do on the sides. If you would've used it flat on there, it would just bend, following the curve of whatever that's under there..
  9. mikebpeters


    Aug 29, 2011
    NS, Canada
    I totally see your point and will try that. I was hoping that 1 1/2 inch think material would provide enough stiffness, but obviously not.
  10. Good luck! Not saying this was actually the problem, but it's an option... also, easy with the Titebond, sometimes I see people soaking their working piece with glue, that's not necessary. I divide my glue with a clean piece of cardboard, creditcard size. If every inch of the glueing area is covered, it's okay. And Titebond should be applied only to one piece of the two you're glueing (I did this wrong not long ago, too much glue too I guess).
  11. Big B.

    Big B.

    Dec 31, 2007
    Austin, TX
    Looks like a lot of glue and not enough pressure. Roberts idea of a caul across the center of the clamping plate is definitely a good idea. When face gluing wide veneers and tops I use a small foam paint roller to apply the glue. A nice even coat on each gluing surface works for me. Like a coat of paint on a wall, a thin coat layer but important to cover every millimeter of each gluing surface. Another method using thin veneer is to iron it on.

    Apply glue to each side of the glueing surface (again I suggest a roller) and let it sit open till it is dry but still tacky when you drag a fingernail across it. I was taught to do this with titebond II but I know white elmers style glue will work as well. Another tip for knowing its ready is that the glue will lose its milky look and become clear. If you let the glue sit long enough to cure hard it will not work well. Once you are ready to attach the veneer heat a regular clothes iron to hi heat and press the veneer flat with it. Dont use steam :cool:. The heat will flash the glue together and will set almost immediately. Work your way to the outside pushing out any bubbles that may form as you go. Tap the veneer as you go to make sure you are making complete contact as small unglued spots always find a way to start working loose. When you tap you should hear a thump just like tapping a board. If you hear a crackle or click then the veneer is not completely set and you need to repress that spot wit the iron again. Always try a test piece first to get the right amount of heat before you touch your actual workpiece and if it is a face veneer try not to hold the iron in one place to long to avoid scorching the veneer. If done properly this will glue your veneer as strongly as a press and only takes an hour or so. I always use this this method to apply veneer to arched bodies and radius drawer fronts in furniture and it works great. Its also useful for small areas like headstock veneers.
  12. mikebpeters


    Aug 29, 2011
    NS, Canada
    Thanks Big B. I like your idea too. I did use a roller but it is clear to me that I did use too much glue now, and even though I put a lot of pressure on my cauls it clearly wasn't enough. I really like your ironing idea and I will certainly give that a shot.

    I do appreciate your instructions and cautions. They make a lot of sense to me.
  13. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    While your clamps reached fairly well inboard on your "cauls," they look like they were at the edge of the actual veneer, spanning themselves over mostly open air. So the veneer was essentially edge-clamped. Combined with those boards being only pine, and with the grain in the wrong direction, the boards were easily able to bend.

    Use of a few stiff beams running crosswise above the pine boards, between pairs of clamps, would likely have worked out fine. This would look something like Robert's center beam, except a few of them running cross-wise. Turning the caul boards 90 degrees might have worked also. Another possible solution is to reduce your 18" width of the boards to close to that of the veneer, so you get some pressure inboard a bit on the veneer.
  14. You don't need a lot of clamping pressure. It is a misnomer that you need tons and tons of pressure, what you need is even clamping pressure. You could get away with 20lbs of clamping pressure if it is even.

  15. pilotjones

    pilotjones Supporting Member

    Nov 8, 2001
    Let's make sure we don't confuse force and pressure.

    To use round numbers, let's assume the glue interface area to be 15 by 20 inches. That give us an area of 300 in^2.

    If we used a vacuum setup, which is common practice and sufficient for veneering, that gives us over 14 psi, or pounds per square inch. That means that we are actually applying 4200 lbs of force to the whole glue area. (And that is assuming no cauls, or cauls only equal to the glue area. Oversized cauls could be used in the bag to provide additional force, if it's designed properly.)

    If I instead lean my upper body over the plank, which common sense and general experience indicate is insufficient to give proper squeezeout and clamping pressure for such a large area, I might be applying 75 lbs of force - which creates only .25 psi in the bond area.

    While a vacuum rig may possibly apply more force than is necessary, my feel for it is that it is not hugely over applying.
  16. mikebpeters


    Aug 29, 2011
    NS, Canada
    I've admittedly been a bit nervous about gluing laminates, so I am postponing that bit for a bit while I continue to research.

    Meanwhile I got my book matched curly redwood back piece glued up and cleaned up. I splashed some mineral spirits on it and I am extremely happy with what I see. The front promises to be at least as nice.

    I have also finished up my templates


    my own design, but not a huge amount of novelty. A bit of ric inspiration, a bit of dingwall inspiration.


    the only thing that appears to me to be novel is a half cutout on the bottom. I think that this will really highlight the neck lams, given that there will be top and bottom cover plates that will otherwise cover them.

    I have repeated the theme on the headstock as well.

  17. mikebpeters


    Aug 29, 2011
    NS, Canada
    got a bit more done today. Cleaned up the outside a bit more in a spot that wasn't quite as smooth as I wanted and then I routed in the control cavities.

    I don't expect to ever use these cavity routings to rout with, but more for visual placement. I also know that the cavities in reality should be the other way around, given the 2 layers that I have, but i did it this way 'just because'. In truth the two templates are utterly interchangeable with the exception of the 'fish' cut out on the bottom so it doesn't really matter.


    However, progress is exciting!

    Even though it is for my other build I glued up some thin pieces tonight based on what I learned a little earlier in this post. I have the clamps used better. Used a top and bottom cross piece to apply the pressure tighter and more across the centre and I used a LOT less glue so I am eager to see how it looks in the morning. Oh, as an aside also learned that what I was calling 'cauls' should have been plattens. Its a wasted day that you don't learn something :)

  18. mikebpeters


    Aug 29, 2011
    NS, Canada
    Well, I have been out of town and then busy so haven't gotten much done, but at least I have made some progress.

    After my poor showing in my last attempt to glue veneers I have improved pretty much every aspect. I now have better quality and more F clamps,


    I have glued MDF on the inside of my clamping plattens (I also learned that this seems to be the correct term as opposed to cauls like I was referring to them before) and my gluing technique has improved dramatically.

    I have also chosen to glue one layer at a time rather than all three at once, so all in all I am very pleased


    here is a pic of the edge of my topcover. I don't expect the veneers to show much except for in the area of the fore arm ease.


    I even got as far as rough cutting my top out so I could admire it


    still a few things to do of course :)
  19. mikebpeters


    Aug 29, 2011
    NS, Canada
    Tonight was my first night in preparing the neck to be able to mate my top sheet to it.

    I want to keep the same motif that I have on the bottom of the bass and on the treble side of the headstock and mirror it a third time on the bottom of the fingerboard.

    I saw the term fretboard flourish on somebody's post and I love it. (sorry to whoever I lifted this from)

    As my top cover will cover the wings and NT neck I needed to ease the neck enough to allow it to be flush with the wings so that the fingerboard can be flush on top of either/both once the top sheet is on and because I want just a hint of the neck to show at the very bottom of the fingerboard - to carry my motif I added a bunch of work for myself

    I had already thickness sanded my wings to the height of them plus the top sheet being exactly the height of the entire neck.


    Now I just needed to figure out exactly what I want my 'flourish' to look like and where I want it. I drew it out exactly to scale and then used an existing fretboard (not the one I am going to use) to help position it and then I used carbon paper to draw the shape on the neck


    Then I flipped the neck over and took it to my router table


    after a bunch of sets of passes I was almost done. I left a small piece at the bottom of the neck to make routing easier. It was the very last thing to go on the last pass


    I'll take the last little bit down with sandpaper, and then I have to finish the detail around where the flourish will butt up. If you look closely you can see that I have 3 veneers between my wings and my neck - the same three that will separate my top and bottom covers from the wings/neck.


    and then I have to cut out what almost looks like a neck pocket on my topsheet to fit. I'm not looking forward to that but I know that if I can do a good job that it should look pretty nice.

  20. Looking good!