BYO: Best glue for laminating backs & sides?

Craig Bumgarner

BYO (Build Your Own): I used lamination for back and sides for the first time. I used Titebond glue. They came out good, but they felt damp for a week afterward and are trying to warp out on me. I've got them clamped up in the molds to keep them stable. Not too worried about them, but got to thinking if Titebond is really the right glue to use.

Michael Collins recommends Titebond in his book. I found with what I thought was about the right amount of glue, it starts to set faster than I can get the sides in particular clamped up. I think I just made it on the sides. I used more glue on the back for that reason, but in hindsight this was a mistake as the back was very slow to setup, too much glue. Michael says too much is better than not enough, but I think too much is just as bad as not enough. BTW, I used a thin foam roller (WEST epoxy brand) to apply which does a nice job of evenly distributing the glue.

I'm wondering if a plastic resin (urea formaldehyde) glue like Weldwood or Resorcinal or maybe liquid hide glue would be better. Would it set up faster and harder? I've used epoxy a lot for other things, maybe that would be good though I hate the mess of working with it. I feel like waterbased Titebond is kind of rubbery and certainly sends the veneers into gyrations that take at least a week to recover from. I question whether the Titebond might effect the resonance of the back and sides in a detrimental way. The tap tones on the back and sides were terrible shortly after laminating and only marginally better now. A harder glue seems more appropriate for this aspect of building

Thoughts? What have others used? I wonder what the Selmer factory might have used? What would they have had available? Hide glue seems like it would set too fast. Maybe they molds were easier and quicker to use than my rig which takes 20 individual clamps. Urea glues were probably available, at least after WWII. Hmmmm.........old secrets.

Craig

Swing 69

Interesting topic, hope you get some replies but sorry, can't help you. I have the story of selmer/mac book and the michael collins one. I'll have a look.Good luck.

Bones

Craig,

Great topic!

I have not tried to laminate yet so I can't help but I'm planning to try that next so I'm interested in the replies.

Did you make forms like in Michaels book?

Where did you buy your veneers and how did you joint/bookmatch the back?

Thanks

Craig Bumgarner

Bones wrote:

Did you make forms like in Michaels book?

Where did you buy your veneers and how did you joint/bookmatch the back?

Thanks

I did make forms like Michael's book and they worked well. The sides especially turned out really good. The forms shown in Francois Charle's book are probably better for production but harder to build. If you don't have the book, they used a female mold like Michael's but instead of a flexible caul and multiple clamps, they use 3-4 blocks shaped to the mold and a single clamp on each. The clamps are suspended on straps from the lower mold. This is much simpler than it sounds, but it is difficult to get the shape of the two sides of the mold to match perfectly. I've done some fiberglass molding and if I ever really got into this, I'd consider molding the clamping blocks. But, frankly, Michael's system worked very well.

I did not get quite enough pressure in the very middle of the back and have a slight ripple there. I think it will sand out. Michael shows two clamping beams across the back, I'd use three next time. Plane a slight curve into them to put more pressure in the middle. I used too much glue on the back and I think that probably hurt too.

I bought veneers from Certainly Wood. It took a while to get their attention, but I was patient and eventually they returned the favor by coming forth with beautiful mahogany, poplar and black walnut veneer all in the right sizes and grain. I could not find .030" venners and had to settle for .022". I used four as Michael suggests. Worked good, seems very light and stiff, just what you want.

I did the center joint just as Michael shows. Shoot the edges with a plane, tape the joint on one side and then fold open, finger in a little glue and the tape the other side. Use some cross pieces first to pull the joint together tight. Let them sit a long while. I only let mine sit for four hours and it started coming apart when I laminated. Fortunately, it did not get out of control, but I made not to let it sit longer next time.

Craig

Bones

Hi Craig,

Ok I'll follow Michael's book as far as the forms.

Thanks for the tip on Certainly Woods.

Were the walnut veneers that they sent you 'bookmatched'? I'm used to buying solid back and side sets that are cut from the same billet and are a matched mirror image.

PS- with that .022" veneer be careful with too much sanding!

Craig Bumgarner

Bones wrote:

Were the walnut veneers that they sent you 'bookmatched'? I'm used to buying solid back and side sets that are cut from the same billet and are a matched mirror image.

PS- with that .022" veneer be careful with too much sanding!

Yes, bookmatching is readily available with veneer as each piece is sliced successively off the log and stored that way. Just ask for bookmatched pieces.

Yes, .022" doesn't leave much room for error, so the molds have to be right on. BTW, I used MDF for the molds, but then epoxy coated them and refaired them with epoxy putty to get them very accurate, smooth with a hard, dense surface. I think this helped the final surface which turn out good. The epoxy also helps keep the mold stable over time.

The nice thing about walnut is it is considerably less expensive than most other dark wood we associate with guitar backs and sides. I didn't want to commit $50 worth of rosewood veneer on my first try.

Craig

Craig Bumgarner

One thing I am noticing about my laminated back, sides and liners is that they are going through some serious shape changes as the glue hardens up. The sides and liners draw in on the ends. The back has developed a 2" over 16" bow across the panel in the wrong direction. The sides pulled back into shape easily enough. The back probably will too but it would be better if it weren't so.

My impression is that it has taken over a week for the Titebond glue to get hard. During that time, there has been a lot of moisture absorption from the glue and then loss as the parts dry out. I can tell the glue is getting hard now because the pieces have a much more noticeable ring to them where as a week ago, it was a dull thud. When I cut the sides to width this weekend w/ a bandsaw, the sides emitted a loud, high pitched vibration that made my ears hurt (yeah, that's what I'm talkin' about!).

Next time, I will store the parts in the molds for a week, lightly clamped to shape. That may not be enough for the back, I might have to make a clamping devise with an exaggerated bow in the right direction.

Again, maybe a different kind of glue that gets hard right now is the solution. I'll definitely try something different next time.

Craig

bill raymond

Titebond, as you found out, works fine, but requires a bit of time to develop its hardness and quits warping the laminated work. I'm sure Selmer used hot hide glue, but that would be difficult to do as it gels as soon as it cools a bit. Others have had good luck with urea formaldehyde glues or other "plastic resin glue" such as WeldWood or other brands--Constantine's has a "press bond" glue for laminating, for example. I agree that epoxy is a mess.

I've not had bad results with Titebond, but am going to try PRG one of these days.

bill raymond

I should also include a photo of the laminating form I am using.

Craig Bumgarner

The new AJL website was announced over in the Welcome forum and I was ready how Ari lets laminated parts sit for a couple months after laminating. That sounds like a very good idea. The back & sides I laminated were very mobile for the first couple weeks, changing shape daily. I'd leave them clamped up in their respective molds so they were more likely to retain their proper shape.

Bill,

I missed your last post, just saw it now. Thanks for posting your thoughts on glue and picture of mold press. Titebond is so convenient for most things, but for backs and side, I'd like to find something that sets up harder and effects the wood less. I'll try PRG next time.

Craig

frater

Probably I'm completely off topic but I thought to share this. Recently I was reading an interview to a luthier called Bariselli who does Selmer copies here in Italy (with a real pliage, incidentally). It seems he had a lot of problems with laminates until a day, eating pizza and watching the oil stains on the cardboard box, he had the idea to use cardboard to absorb humidity from the freshly glued laminates.
I don't know if this makes any sense to you!... maybe he just had too much Chianti with his pizza!