posted August 03, 2007 10:04 AM
We prefer Gorilla Glue (or PB Bond when I can get it).
We lay down wax paper along the seam, brush on a thin as possible coat of glue on one panel edge, mist the matching edge with water, then clamp.
I made a custom router base with a wide slot cut out of one edge all the way to the bit. This way I can slide the router bit into the the glue that has expanded out of the joint and route it down flush with the face of the HDU board.
The weight of the HDU makes the oozing glue spread outward on the bottom. Its very flat, but still has to be sanded or routed down.
I was wondering if anyone has a better method. I never use these glues to laminate HDU after seeing how much they expand. I would imagine that it would take a lot of weight to hold the panels together to keep them from bulging. If you could stop the expansion, would the integrity of the glue joint still be there?
-------------------- Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 sherwoodsign@sbcglobal.net Posts: 5403 | From: Crystal Falls, MI USA | Registered: Apr 1999
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posted August 03, 2007 10:52 AM
Dave, I've used the Gorilla glue many times to mount backer boards to my one-sided signs. But I run screws in them about ever 4 or five inches to hold them down until they cure. The screws are hidden by the posts. Had one hit by a bulldozer once. It snapped off both posts and broke the sign in two but the backer boards didn't budge.
With the PB bond, you are only supposed to apply a thin layer of it...only enough to "color" the HDU. You can also spray mist a little extra water which will slow the cure process a bit. I lay mine out on the workbench and pile blasting sand bags in the center and clamp the edges. I slice the glue off with a sharp woodchisel. I am getting ready to blast one of these and just took two more out of the clamps. They were done with PB240. I wouldn't even attempt it with Gorilla glue because it tends to expand more than the PB240 does.
I have also had good success with using West Systems epoxy. But you need to use the filler in the epoxy or it will run out of the joint. With urethane glues, I look at it like welding...using the same material to join two of the same......I worry about the differential in expansion/contraction betwwen epoxy and HDU. Epoxy can be messier and harder to clean up too.
[ August 03, 2007, 10:58 AM: Message edited by: Wayne Webb ]
-------------------- Wayne Webb Webb Signworks Chipley, FL 850.638.9329 wayne@webbsignworks.com Posts: 7404 | From: Chipley,Florida,United States | Registered: Oct 1999
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posted August 03, 2007 12:42 PM
We use MDO in the center of our signs for single face or as a backer for the larger single face. For 2 faced we put 1 side face down. Tuck some waxpaper around the edges. Spread West Systems epoxy on the sign back, but not closer than 1/2" to the edge, put on the MDO, then West Systems epoxy then the second sign face. Cover it with pieces of coroplast, Then make sure the edges are lined up and put cement blocks on top. Let sit over night. Sometimes there is a little ooze- use a cheisel to get it off. Then we seal the edges with West Systems epoxy mixed with their fairing filler (or pure sign foam dust). Mix enough fairing filler in to make peanut butter consistency. Smooth on with squeegee. Let it dry for 7 hours- then sand smooth with 220 grit orbital sander. Prime and paint. You won't have b problems with the edges de-laminating.
Diane
Posts: 405 | From: Malta, NY | Registered: Jan 2003
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when you glue the mesh in the middle you could jump on it and not break it.
I feel that in our cliamate(Florida) that when you glue HDU to a un-compatable product that has movement( MDO ) that you will have a potential for delamination. epoxy harden with no room for movement (correct me if i am wrong). we have also used PB brand urathane adhesive( comes in a caulking tube) to Bond HDU with much success. you can get it at lowes or home depot...less messy for smaller glue ups.
Lovelady
-------------------- "We have been making house calls since 1992"
Chris Lovelady Vital Signs
NOW WITH 2 LOCATIONS! Tallahassee, Florida Thomasville, Ga.
posted August 03, 2007 05:51 PM
Dave - I assume you are talking about butt jointing two pieces together rather than laminating one piece over another.
For joints we normally cut a slot in each end of the panel with a .25" slot cutting bit (a biscuit jointer does the same thing)and then insert a quarter inch spline of either PCV or aluminum. All of this is glued up with West System Epoxy. Like you we use the wax paper to keep the glue from getting all over everything.
I don't care for Gorilla Glue because it foams up so much
-------------------- Chapman Sign Studio Temple, Texas chapmanstudio@sbcglobal.net Posts: 6306 | From: Temple, Texas, USA | Registered: Nov 1998
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posted August 03, 2007 07:41 PM
Ray, you are right. I'm talking about butt or edge joining. Mark (I think) at Coastal Enterprises called me. He said first I was using too much glue and someone gave me bad advice about the method.
He said to wet both pieces by spray misting, then wipe off the excess water. Enough water will remain in the pores to provide the necessary moisture. Then wipe on a very thin layer of PB Bond. It foams up much less than Gorilla Glue so the squeeze out will be minimal.
With this method, I may try suspending the boards an inch or so above the table. If the foamed up squeeze out is minimal, my router with the cut out base will take care of it in seconds.
I used to use epoxy, but when sandblasting, the urethane glues blast away much closer to the same rate as the HDU does so you don't get that hard raised line along the glue joint. Of course that's not an issue when routing.
Edit:
Don't get me wrong, I'm not having problems. I've had zero failures with my methods. I'm just looking for a way to improve or speed up the process. I'm like that. Always looking for a better / faster / more efficiant way of doing things.
[ August 03, 2007, 07:43 PM: Message edited by: Dave Sherby ]
-------------------- Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 sherwoodsign@sbcglobal.net Posts: 5403 | From: Crystal Falls, MI USA | Registered: Apr 1999
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posted August 03, 2007 09:32 PM
I have never used the wax paper, great idea. It seems to get the PB glue to spread thinly is my challenge, I also use the misting technique with PB240 but usually use a brush, can it be thinned or is there a technique you guys use to get to spread it on thinner?
-------------------- Jeff Wisdom SignWorks info@oregonsignworks.com Posts: 450 | From: Oregon | Registered: Dec 2005
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we have used bisket and PL brand urathane adhesive to glue together when installed. here is one we did and also used the panel clips to install on a wall. aslo it shows our homemade grain frame...the sign was 8'x12' HDU.
posted August 06, 2007 02:34 PM
Here's what I've had success with. Spray/mist one edge with water. Run a narrow bead of G Glue down the center of the other edge. Bring the two edges together and slide them back and forth against each other. This spreads the glue evenly. Clamp. Within a hour, small beads of glue will appear along the joint. Before the beads get hard, I use a putty knife to remove them.
joe,
Makin chips and Havin Fun!
-------------------- Joe Cieslowski Connecticut Woodcarvers Gallery P.O.Box 368 East Canaan CT 06024 jcieslowski@snet.net 860-824-0883 Posts: 2345 | From: East Canaan CT 06024 | Registered: Nov 2001
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posted August 06, 2007 03:26 PM
Steve, I'm going to order some soon. The problem is that for a sandblasted sign, the Magic Smooth would get as hard as a liquid epoxy does, and that leaves a high ridge at the glue line. For routed signs it doesn't matter.
But I'm going to order sopme soon because of all the other uses it has.
-------------------- Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 sherwoodsign@sbcglobal.net Posts: 5403 | From: Crystal Falls, MI USA | Registered: Apr 1999
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