posted
Another sign company asked me about a 15 lb. foam sign he made warping. Looks like the sign is about 2'x4'. It's warp about 1/2" over the 4'. He primed the sign with automotive primer, then painted all with 1 shot. He didn't paint the back. He's wondering if the primer caused the problem. I think it's because he didn't paint the back. His customer wants it redone. Any thoughts? Thanks
-------------------- Tom & Kathy Durham House Springs, MO Posts: 654 | From: House Springs, MO | Registered: Apr 1999
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A friend of mine who is a sculpture works with sign foam a lot. I have noticed that the bare signfoam left outisde of his shop kinda turns dark in color and even looks to be either shirking back a bit or simply deteriorating.
-------------------- Signs by Alicia Jennings (Mudflap Girl) Tacoma, WA Since 1987 Have Lipstick, will travel. Posts: 3813 | From: Tacoma, WA. U.S.A. | Registered: Dec 1999
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posted
I'm guessing the face is the concave side. Yes priming one side especially with the auto primer will warp it. We do routing for a shop that uses the polyester primers and their panels are warped alot of the time and that's priming 2 sides. I think they put it on too heavy. I can't believe how lazy/cheap people are that they can't even paint the backs. How is it mounted is there any way to back it up or pull it flat?
-------------------- Eric PA Posts: 149 | From: Intercourse, PA | Registered: Jun 2004
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posted
The same number of coats of paint need to be put on the back as are on the front. Also, the area blasted or routed away creates tension on the face because that area is thinner than the rest of the sign.
The thickness of the material, the method of mounting, heat, and any number of other factors will cause warping. I would suggest taking the sign off the wall, backing with some rigid material, and reinstalling. Of course, putting screws through the face into the wall would pull the panel flat, also.
We paint all our HDU with water based paints and the problems of warping have lessened than when we were using enamels.
-------------------- Chapman Sign Studio Temple, Texas chapmanstudio@sbcglobal.net Posts: 6306 | From: Temple, Texas, USA | Registered: Nov 1998
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I've always painted both sides of mine, equal coats, with acrylic latex and never had one warp that I know of. I also always install 2x4 foam 'backer boards' on my single sided ones and maybe that helps too.
-------------------- Wayne Webb Webb Signworks Chipley, FL 850.638.9329 wayne@webbsignworks.com Posts: 7403 | From: Chipley,Florida,United States | Registered: Oct 1999
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Try laying the sign on its face, on a smooth flat surface. Place some used vinyl carrier paper under it so that it does not stick, then place a flat panel, like plywood on the back. Weigh it down with something heavy. let set for a few days and see if it won't straighten out. Then immediately paint the back two or three coats of topcoat.
-------------------- Wayne Webb Webb Signworks Chipley, FL 850.638.9329 wayne@webbsignworks.com Posts: 7403 | From: Chipley,Florida,United States | Registered: Oct 1999
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posted
This is from the precisionboard.com website:
quote:Precision Board Plus FAQS
Should I prime and paint all sides of my sign since Precision Board Plus does not absorb moisture? Yes, Precision Board Plus does not have grain and therefore does not have the beam strength that comes with grain. This means Precision Board Plus can be pulled in the direction of the drying paint. All paints shrink as they dry which causes tension across the surface of the sign. The higher quality of paint the more strength this shrinkage has. Painting both sides of the sign with equal thickness of paint provides equal tension and will keep one side from drawing the other. This is especially true of dark colored, heat absorbing paints. See our Paint Tension Data Sheet.
Does Ultraviolet from the sun affect Precision Board Plus? Yes. Left in the sun unpainted, Precision Board Plus will start to discolor and turn brown in about 48 hours. Left totally unprotected Precision Board Plus will continue to turn brown and breakdown from UV at about 1/32″ per year. This means about 1″ of deterioration every 32 years. Obviously deterioration is not a problem but the brown color is not pleasing. However, just under the brown surface the cell structure is unaffected. When this surface is removed it is ready for primer and paint. Keeping the painted surface looking good will assure a very long service life.
-------------------- Brad Ferguson See More Signs 7931 Wornall Rd Kansas City, MO 64111 signbrad@yahoo.com 816-739-7316 Posts: 1230 | From: Kansas City, MO, USA | Registered: Nov 1998
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posted
There is a biggish company here that laminates HDU, sandwiching 1/2" or 3/4" thick acrylic in between the 2 layers of HDU for a double-sided sign.
They then use less HDU, as it only needs to be a bit more than the depth of the deepest groove. They have a huge press than can put the weights on, evenly across an 8x4.
-------------------- "Stewey" on chat
"...there are no limits when you aim for perfection..." Jonathan Livingston Seagull Posts: 7014 | From: Highgrove via Toowoomba, Queensland, Australia | Registered: Dec 2002
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Almost everyone tries to cut corners with HDU. Sometimes, a sign will warp even with both sides painted, & even with something laminated to it.
I put some sort of internal structure into almost every sign. Wall mounted signs have a piece of 6mm aluminum composite in the middle, reminiscent of swiss-cheese, that is completely encapsulated but not adhered to the HDU.
The insert holds fasteners well, provides stiffness, & with the pocket slightly larger than the insert, everything can move independently so temperature swings don't result in warping.
Obviously, this is a more expensive way to build a HDU sign, but I've removed all thermal expansion issues, there's no moisture migration issues ( from using MDO as a backer) & warranty "call-backs" have been eliminated.
-------------------- Rodger MacMunn T.R. MacMunn & Sons C.P.207, Sharbot Lake, ON 613-279-1230 trmac@frontenac.net Posts: 472 | From: Sharbot Lake, Ontario | Registered: Nov 2003
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This one is double thickness 1.5" HDU (3" thick)and has aluminum extrusions traversing horizontally and extending 3" or so. The extrusions of course stiffen this sign and double as "tenons" to join to mortises in the fiberglass columns. I do all my double-side signs this way.
My single sided signs, on the other hand, have backer boards and, on this one, the posts are screwed straight into the HDU backer board and part way into the sign panel with galvanized lag bolts. Of course they are painted on both sides with acrylic latex. There are 3 of these at the entrances to the city since about 2006 or 7 and none has warped.
-------------------- Wayne Webb Webb Signworks Chipley, FL 850.638.9329 wayne@webbsignworks.com Posts: 7403 | From: Chipley,Florida,United States | Registered: Oct 1999
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quote:Obviously, this is a more expensive way to build a HDU sign
Cutting corners, not building a sign properly, carries costs with it, too. Loss of customer goodwill — how much is that worth? Client trust may not be quantifiable, but it surely has value. And what if a job needs to be redone or reworked? Then the expense of a poorly built sign becomes obvious. My muffler shop used to tell me, "Do you want us to do it right or do it over?"
I know a sign guy that routinely uses flat plastic in sign cabinets that require pan faces. He says he's giving the customer a cheaper alternative. Of course he doesn't tell them they will see the lamps. The look of a sign showing dozens of bright white dots when lit with LED lamps has angered more than one of his customers. Yet he continues to spread the ugly. He thinks everyone is a cheapskate and will accept junk work to save money. Perhaps because he is a cheapskate himself? If a sign person makes the decision to give substandard service or materials, or to not use accepted industry practices, at the very least he should clearly explain the consequences to the client. It's one thing to be cost-conscious, but another thing to deceive a customer in the name of economy. It is encouraging that many of us strive to use best practices, giving the customer a better value. The fact that this question about SignFoam warping was asked shows a desire to correct a problem and avoid it in the future.
I believe that most people don't necessarily want the cheapest possible sign. Rather, they want a good value, and that's not the same thing.
Regarding HDU, if a person wants a cheap sign, why buy this higher priced substrate to begin with? HDU is a wonderful product. It can potentially look good and endure for a long time, so shouldn't our finishing and installation of it be commensurate? Otherwise, are we really giving people a good deal, or just wasting their money?
-------------------- Brad Ferguson See More Signs 7931 Wornall Rd Kansas City, MO 64111 signbrad@yahoo.com 816-739-7316 Posts: 1230 | From: Kansas City, MO, USA | Registered: Nov 1998
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