Glue for laminated rib construction

[jimialeggio5 at comcast.net]

I"ve used both the Uni-bond 800 UF and Gorilla glue for all kinds of laminations 
curved and otherwise. Both perform under exterior high moisture conditions and 
sun cycling with no creep.

Of the 2 I like the polyurethane for its machinability in secondary operations.
Its often my favorite choice for this reason, even though it is a pain to 
spread. ---An 8" very flexible drywall knife wiped cross grain helps move 
this part along considerably.

I really like the Uni-bond 800 for the ease of getting the glue spread on a 
bunch of laminations very quickly. I also really like its rigidity, especially 
on curved laminations. Its only real down side from my perspective is it is 
really hard on knives for secondary operations. I only use it where secondary 
planing/jointing/shaping operations will be performed by carbide tooling. I 
and haven't noticed any clogging issues on the drilling front. 

Terry...regarding the color of the Unibond, have you tried controlling glue line 
color by using different colored catalysts, which Vacupress supplies? I use the 
dark catalysts for mahogany. There is a light catalyst for light woods...but 
maybe that's what you've already tried. Don't know if there are more than 1 
light catalyst.

Dale...the Unibond does have some out-gassing to it during use. I'm pretty 
sensitive to these things, but it doesn't seem to irritate my sensitivities. 

I agree will you, Dale about epoxy...I never use it for anything other than 
fixing boo-boo's, and very occasional minor structural gap filling.  It really 
wants a thick glue line...for this reason I will not use it on joinery. 

As a side note, in the historic preservation field, in the late 80's early 90's
epoxy was embraced as a cure all for all kinds of difficult, skill intensive 
repair issues in buildings. Since then, much time hase been spent fixing failed 
epoxy work...mostly with close fitting goints replacing the monolithic epoxy 
constructions.   

Jim I




Even clamping pressure would concern me also. I not suggesting that you can't 
successfully use Bolduc glue for a pinblock. For building pinblocks, because of 
the clamping issue, I use either epoxy or 2-part urea-formaldehyde (UF) 
adhesive. The UF is water cleanup. It cures rock hard and can fill any size gap. 
No actual clamping pressure is required (just like epoxy) - you really only 
clamp to position things and so that you don't have more glue than wood.

The UF adhesive I use is Unibond 800  http://www.vacupress.com/veneerglue.htm  
Very easy to use.

You can also use the UF for ribs - although it leave a yellow glue line. Doesn't 
bother me, but it is yellow.

I've also used Bolduc and Titebond Extend for laminating ribs. Both work well. I 
have had a few slabs of ribs change curvature while the wood MC equilibrates 
with the shop. No real big deal, but if you use these water-based glues I simply 
suggest waiting a week or two before using them - recheck the radius to be sure 
of what you have. The UF avoids this concern (real or imagined).

Terry Farrell
  ----- Original Message ----- 
  I've used the Bolduc glue for pinblock lamination for several years when I'm 
oversizing them or building up multi-level blocks. The only issue for me is even 
clamping pressure and the size of the panels that I've been working with since I 
don't have a full soundboard press system (still buying them from Andre with 
nary a complaint other than I ache to be making them myself :-). I don't see why 
it wouldn't work with rib stock laminates as well. As I recall, Andre told me 
several years ago when I was interviewing him for the Journal that he uses his 
own glue for the pinblocks he makes as well. You might ask him.

  Paul





  -----Original Message-----

    Belly heads
    I've been gluing up my own laminated rib stock & my pinblocks.  I  won't use 
epoxy because it too is toxic to my body & expensive.  I'm open for suggestions.  
     I need to glue up a bunch of ribs  tomorrow.  I like th Bolduc for my 
pinblocks & bridge cap applications because it doesn't clog drill bits or have 
adverse affects on tuning torque.  I believe Andre usu to glue up his own blocks 
& panels.
    Any help?
    Thanks
    Dale