posted
What is the compatability of HDU used with PVC. I have an HDU sign that will have some dimensional trim elements on it. The pieces will run the entire length of the sign - approximately 10 ft. At Home Depot I found some trim pieces that are exterior, paintable cellular vinyl PVC and they would work great for what I need, saving me the hassle of cutting and routering them by hand (don't have a computer driven router). I would glue or silicone them to the HDU. I guess what I'm wondering is if there is a big difference in expansion/contraction. The HDU and PVC would both be painted a dark charcoal grey. It is going to be a fascia sign on a north face so not much problem with heat absorbtion from the sun. Any experience, caution or tips?
[ October 25, 2003, 08:52 PM: Message edited by: Dan Seese ]
-------------------- Dan Seese Dan Seese Studios, inc. 3830 Capitol Drive Ft. Collins, CO 80526 (970) 226-0618 danseesestudios@qwest.net Posts: 18 | From: Fort Collins, Colorado | Registered: Mar 2003
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posted
That's a dang good suggestion Joe. for what it's worth Dan, I've been doing what you mentioned, along with pushing the envelope with all kinds of other wacky combinations, successfully for some time. It never really occured to me to ask the manufacturer for their input. (even if they said no, I'd try to find some how to do it anyway, just to prove them wrong).
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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Maybe a mechanical fastening system might be the way to go. Not quite sure what difficulties it would pose in your specific situation, but I often find when a chemical concern arises, eliminate the chemicals. Sometimes some predrilled holes, a few well placed wood pegs, screws or even a with a minimal amount of adhesives can be effective. They can bridge the expansion differences that a direct adhesion may not.
Just a few thoughts in another direction... Rapid
-------------------- Ray Rheaume Rapidfire Design 543 Brushwood Road North Haverhill, NH 03774 rapidfiredesign@hotmail.com 603-787-6803
I like my paint shaken, not stirred. Posts: 5648 | From: North Haverhill, New Hampshire | Registered: Apr 2003
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posted
Danthonia Designs (see Signcraft from last year)laminate PVC to HDU 'all the time' more or less. But they have a big roller press, and maybe have worked out a special glue to accommodate thermal expansion differentials. I'm just guessing that. Could be worth a query to them.
-------------------- "Stewey" on chat
"...there are no limits when you aim for perfection..." Jonathan Livingston Seagull Posts: 7017 | From: Highgrove via Toowoomba, Queensland, Australia | Registered: Dec 2002
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I would research this first with the various manufacturers. HDU manufacturers boast about the stability of HDU, which makes me think it does not expand and contract much. On the other hand I've read the suggestions on installing PVC from the manufacturers, and they recommend oversize holes to allow for expansion & contraction.
HDU has a shearing strength only equal to the strength of the bond from one HDU cell or bubble to the next. Whenever I have had any glue failure between HDU and whatever, there has always been a very thin layer of HDU still attached to the glue. This tells me that if enough force is applied, the cells of HDU will seperate from each other.
If a length of PVC is glued to HDU, and if there is enough difference between the expansion of the HDU and PVC, and if the thermal expansion of one of the products is strong enough, there will be a failure of one of the products at the glue line and in my opinion it would be the HDU.
If this is the case, a loose mechanical connection would probably be in order.
posted
I did some trim pieces a few years ago that were 10 foot long strips of closed cell foam, 2" thick, with strips of dark blue SG acrylic laminated to them with Sonaborn construction adhesive. WARNING! don't try this at home! The expansion of the acrylic literally ripped big chunks of the foam out and looked like a roller coaster. It wasn't pretty! hehe. In your situation, I would imagine, the foam would have very little expansion, and the PVC would have more, to some degree, resulting in a similar situation. I'm by no means an expert at this, but I can say that by trial and error, I know what NOT to do! hahaha Oh well, live and learn.
-------------------- Dave Utter D-utterguy on chat Sign Designs Beardstown, Il. signdesigns@casscomm.com Posts: 777 | From: beardstown, illinois, usa | Registered: Mar 1999
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Thanks for the suggestions & insight. I'll call Sign Arts or Costal Enterprises today and get their input. I may just go on the safe side and form the trim pieces myself out of HDU. I hate going back and fixing a sign because of short cuts at the front end. Really appreciate your help.
-------------------- Dan Seese Dan Seese Studios, inc. 3830 Capitol Drive Ft. Collins, CO 80526 (970) 226-0618 danseesestudios@qwest.net Posts: 18 | From: Fort Collins, Colorado | Registered: Mar 2003
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posted
I saw an HDU sign with PVC elements today. The PVC was attached with some kind of little nails or rivets or something. Didn't look great up-close. There's ana excellent article on PVC in the new SignCraft. Aparently, PVC expands & contracts quite a bit.
-------------------- Glenn S. Harris
....back in the sign trade full time. Posts: 293 | From: Baton Rouge, LA, USA | Registered: Jul 2001
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posted
The expansion/contraction coefficient of PVC should roughly be 7-10 times that of HDU, depending upon the plasticizer content.
-------------------- Kent Smith Smith Sign Studio P.O.Box 2385, Estes Park, CO 80517-2385 kent@smithsignstudio.com Posts: 1025 | From: Estes Park, CO | Registered: Nov 1998
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![[Dunno]](graemlins/dunno.gif)
![[Eek!]](eek.gif)
Oh well, live and learn.
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