posted
I bought a piece of Polymetal (similar to Dibond) for laminating between two pieces of HDU to make a 5.5'x4' double faced sandblasted sign. I cut the polymetal to fit and scuffed one side with an orbital sander. I picked up one of the scraps of polymetal and bent it to see how well it held together. To me it doesn't seem like that great of a bond. So, I tried one of my Dibond samples and it seemed to be a little stronger bond. has anyone used Polymetal for this?
I haven't been able to get Dibond in my area without paying big bucks for the freight. But, the polymetal wasn't cheap either at $139 a sheet for a 6mm 4x8.
If I do use this stuff, I'm thinking seriously about using not a few screws as extra insurance. I didn't want to have to do that but, I don't want this sign coming apart later either.
Any ideas on this?
[ June 10, 2003, 09:48 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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I'm a little confused Wayne, You bent a scrap piece of polymetal and the layers of aluminum and poly separated? . . . Or do you mean that some HDU you glued to a scrap piece of polymetal separated?
If it was a thin piece (strip) of polymetal, I could understand how it would bend, and once the ploy inside was crushed, the aluminum would separate a little around the crease. That would never happen on a large panel - especially with that 6mm which is a rigid monster. It makes a GREAT core or backing for HDU. Scuff it with coarse grit to give some tooth and glue with PL, Gorilla, PB Bond, West, or the like.
I'd hate to see holes through the face. You could screw through the Polymetal into the back of the first HDU face to hold it in place while the glue dried, you'd still have to clamp the other face on. But then your screw heads would get in the way of gluing the second face...Personally, I'd just glue and clamp them both on.
No wait - you said this is a sandblasted sign...thats even easier, If you really feel more comfortable having some screws in there, Screw right through the face after the fact, in an area of the blasted background. A little putty and paint over the screw heads and they'll never be noticed. Or have I completely missed the point??
SONGPAINTER Original Sign Music by Sign People NOW AVAILABLE on CD and the proceeds go to Letterville's favorite charity! Click Here for Sound Clips! Posts: 1974 | From: Orleans, MA, Cape Cod, USA | Registered: Nov 1998
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I first peeled the aluminum from a narrow scrap but then tried a larger piece without bending it. It peeled way too easily to suit me. Then I put a piece on the dashboard of the truck to get it good and hot, It peeled even easier but this time the adhesive stayed on the aluminum instead of the core. It just spooks me because I'm afraid that if the HDU tries to pull because of the contracting paint, as others here have had problems with, it could possibly start delaminating at the edges. I will save the piece for something else which doesn't require that much strength. Not for a $3900 sign.
This is what i'm doing now. It is a combination of Monte's and Dave Sherby's method as well as others.
I will rout two .5'' x 2'' dados on the backside of each HDU face. Each 66''x 48''face is 1.5'' 15lb HDU. Incidently, the HDU faces together should weigh 82.5lbs (37.42 kilos) before blasting. One dado will be at the top end and one near the bottom. When the two halves are mated, this will create a 1''x2'' channel for the tube steel to fit into.
Then epoxy the 1''x2'' rectagular steel tubing 67'' long into the dado and laminate the two halves together making a 3'' thick sign.
Then I will have 4 mounts made. Each will be a .75''x1.75''x6'' solid bar welded at 90 degrees to a .25''x4''x10'' flat bar. The solid bar projections will fit just loose enough into the tube steel, epoxyed into the sign, to telescope in and out.
All of these mounts will be pushed into the tube steel until the sign is in place between the brick columns. They will then each be slid out to meet the brick and secured with a set screw. The .25'' flat bars can then be mounted to the brick with masonry anchors.
I had the mounts made at the welding shop down the road. He did a fine job.
-------------------- 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
you might try sex bolts from john perine company in seattle. then you could use a plug cutter to reglue the hdu over the holes never see um after that just a thought
-------------------- sam kinnear stick um up signs redmond wa Posts: 93 | From: redmond wa | Registered: Jun 2003
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Hey Wayne, I really like that reinforcing method you described. That will be fantastic. I'm also shocked to hear about the Polymetal coming loose like that. I've only used it on a couple jobs, prior to my supplier switching product, I had only used Dibond. Now, I've tried bending Dibond and doing all sorts of strange stuff to it and I know it does NOT delaminate. I was under the impression Polymetal was as good ad Dibond. Now you've got me worried.
SONGPAINTER Original Sign Music by Sign People NOW AVAILABLE on CD and the proceeds go to Letterville's favorite charity! Click Here for Sound Clips! Posts: 1974 | From: Orleans, MA, Cape Cod, USA | Registered: Nov 1998
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posted
Hey Sam, I checked out those "sex" bolts. Never heard of such. I'm sure they would come in handy for something. Thanks
Joe, When I was testing the polymetal, I also tried pulling apart a Dibond sample. It was much stronger than the polymetal. Bear in mind that polymetal wasn't a cheap alternative: it was $139 for a 6mm 4x8. I too figured it would be just as good....NOT. There's no comparison. I also tried a sample of Alumalite. The adhesive was much more tenatious on it as well.
I also have some Alumacorr. If I can remember to, I will test a piece of it tomorrow because I have used it for backing a one sided HDU sign.
Maybe those signs you did with PM will do fine without a failure.
-------------------- 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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