Replies

1. 
   RickL | Aug 29, 2007 08:35pm | #1

   Unibond 800

   http://www.vacupress.com/veneerglue.htm

1. 
   sevans | Aug 29, 2007 08:59pm | #2

   Thanks for the reply. I found that site after posting my message. Ordered a gallon.

   Skip....

2. 
   yotonyb | Aug 30, 2007 09:43pm | #3

   Wear gloves and safety glasses and use a respirator (or a mask of some sort).  The powder is very fine.

   Be precise when measuring-out your liquid and your powder.  It's worthwhile to invest in a measuring cup and some spoons dedicated ONLY TO THIS GLUE SYSTEM.  If it calls for one tablespoon powdered catalyst to one cup of liquid, pour the liquid EXACTLY to the one cup mark in your measuring cup, and scoop EXACTLY one level tablespoon of powder.  Remember, you're initiating a chemical reaction that requires a precise mix. 

   Use only what you need.  You always hear that...but it's hard to understand and appreciate when you've only ever dispensed a glue that's always "ready to go."  I don't know how much surface area you need to cover, but if you take some notes about this glue-up, you'll have a good idea of how much to mix next time.  I always went in half-cup increments.  It's easier to clean when there isn't much left...and it won't be a disaster because you guessed wrong and didn't mix enough.

   Mix completely and thoroughly.  I used one of the beaters from an electric food mixer chucked into a drill.  GO SLOW!  Don't spray it everywhere by pushing the gas pedal to the floor.  And don't just stick the mixer in there and give it a few swirls.  Mix for a couple of minutes.  Maybe let it sit for a minute or two, then mix again...keeping an eye on your open time and the time you think you need for the entire glue-up. 

   Clean immediately after use.

   I've seen failures that I attribute to two primary reasons -- poor mixing and poor curing in cold temperatures.  I've seen tremendous successes on bent laminations that could only have been accomplished by the proper application of this type of glue.

   Good luck and good skill!

   tony b.

   
   

   ---

   Edited 8/30/2007 2:50 pm ET by yotonyb

1. 
   sevans | Aug 30, 2007 11:16pm | #4

   Tony,

    Thanks for the great info. I have a good respirator for this type work.  Each glue up covers 635 sq. inches if only one side needs glue. Twice that if both sides need it. Does the glue up need glue on both sides? I am creating a table leg that uses 12  35" long x 1 1/2 wide x 1/8" thick pieces to create a curve with a 4" bend. This is my first bent lamination. I am considering steaming the wood first to eliminate stress. I am using Banak.  Am I over doing it with the steaming?

   Skip....

1. 
   yotonyb | Aug 31, 2007 10:10pm | #6

   Did you place all of your laminations in your form and do a "dry fit?"  If they won't flex, or if they're gonna crack, you'd like to know now!

   You didn't say what material you're using...or how it's milled (plain- or quarter-sawn)...but 1/8" might be the upper limit on thickness.  In quarter-sawn white oak, I've gone slightly less than 1/8", aiming for something between 1/8" and 3/32".  On the chair backs that I was making, the pieces flexed in the form with modest hand pressure.  If you have to apply excessive force, you're asking for an eventual failure.  Again, put it in the form for a test.

   I only put glue on one surface.  I would apply glue to the appropriate surface on the first piece.  Then bring the second piece together with the first and rub them back and forth a couple of times.  Repeat with the next piece...and the next...and the next...until you have all of you laminations together.

   I've seen fellow woodworker steam-bending parts, but the effect of steaming will be lost if you have to stop to apply glue to each piece.  Steam bending demands that you get the part into your form and clamped immediately after removing from the steam chamber.  I don't believe you'll get the benefits of steaming your parts given the amount of time you'll need to apply the glue before you can clamp everything together.  Your piece will have cooled to room temparature by the time you have EVERYTHING glued and ready for clamping.

   Moreover, you'll probably hasten the curing of the glue by applying it to a hot/warm surface.  That completely defeats one of the benefits of this glue which is an open time sufficient to perform this type of work.

   tony b.

1. 
   boysie39 | Aug 31, 2007 11:01pm | #7

   Tony b, that is the most clear and understandable directive i've read on a forum of how to do something that must be very difficult. Ive taken a copy and if I ever need to make something like that it will make it all the easier.Thank you, and all the other Master Knotheads who through their posts make things a lot less feared for the likes of me . Regds. Boysie Slan Leat.I'm never always right  but i'm always never wrong. Boysie

2. 
   joinerswork | Sep 04, 2007 03:39pm | #8

   yotonyb,

   Steambending can be helpful in glue laminating a stiff wood, or a tight bend.  It is done in two separate operations.  We steam bent the laminations for wooden strip canoe stems, (the sharply curved ends of the hull,) and left them clamped in the form for a week.  When we did the glue lamination a week later, the strips had conformed to the shape of the form, and the only thing the glue had to hold was a minimal amount of springback.  By separating the bending, and the gluing into two operations, it simplifies things considerably.  No wrestling with slippery strips of gluey wood til the clamps are in place, less alignment issues to deal with. Fewer worries about delamination due to stresses in the laminations, etc, etc. Woods we used have been purpleheart, osage orange, walnut, cherry, and birch.

   Ray

1. 
   yotonyb | Sep 06, 2007 01:34am | #9

   Ray -- That makes PERFECT sense!  I didn't mean to be dismissive of the original idea of steaming the laminations, but if sevans has the time to do this in two separate steps, steaming and forming for a couple of days, then gluing/clamping, it would certainly compensate for any problems he might experience if his "test fitting" tells him his pieces might not flex as easily as he expected.

   That may very well have been what he meant about steaming them first...it just didn't occur to me that you could do this in two steps...I gotta be more open-minded!  Thanks for sharing!

   tony b.

   ...tucking a new idea in his back pocket that he's gonna share at the shop when he sees his steam-bending friends this weekend!

2. 
   joinerswork | Sep 06, 2007 05:58am | #10

   tony,

   That's what they call a paradigm shift, I believe.  Glad I added a new trick to your bag.

   Ray

3. 
   douglas2cats | Aug 31, 2007 03:10pm | #5

   I've used this stuff with good results. It's the same stuff that either Constantines or Highland HHardware (cant recall which - maybe both?) sell but they sell direct too.

   http://nelsonpaint.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=UA

    

   If you build it he will come.

4. 
   ron123 | Sep 06, 2007 07:03am | #11

   Keep in mind that Urea Formeldehyde causes severe long term health damage, and is not recomended for indoor use.  (Think of it as the next generation of lead based paint.)

   - Ron

1. 
   trm8r | Sep 09, 2007 09:24pm | #12

   I'm not sure if steaming and urea glue are necessary. I have made 5 of these desks with titebond glue and 3/32" laminations. Use a 3" paint roller to spread your glue(speed) and a plastic strip as a backer to help prevent splitting and denting the wood. If you're interested I can elaborate.

   
1. 
   sevans | Sep 10, 2007 06:54pm | #13

   Thanks for the info. I already have the urea glue though. I was concerned about creep so I called Titebond technical support. They suggested that I not use Titebond, but I see by your example that it works. I will keep that in mind when I run out of the urea glue. BTW: I have virtually no creep. Did you see any?

1. 
   trm8r | Sep 11, 2007 03:46am | #14

   It's been a while but I think there was about a 1/2" or more spring-back
   after removing the clamps. As far as creep, depending on the weather, sometimes I can feel the seems between the different wood species. But I I can feel that on solid wood table tops too. The legs have enough flex that the desk will "walk" if I shift all my weight back and forth. Don't know if a different glue would change that.