posted
I'm having a problem with a SignFoam sign I completed roughly 2 months ago:
In a few places, the paint and/or primer is blistering up from the surface. I've never seen this before, and I've done a lot of foam signs. The sign was primed with Jay Cooke's primer and finished with Ace Hardware brand exterior latex housepaint. The sign is Single-faced, freestanding, faces the southwest, and only the face is showing this problem, not the back of the sign(which is exposed to the elements, but not the sun). I called the SignFoam folks, but they couldn't help me.
Any ideas? Has anyone else experienced this problem?
Thanks for your replies and help.
------------------
Posts: 237 | From: ft. collins, colorado,usa | Registered: Mar 2001
| IP: Logged |
posted
Standby. I'm just leaving now, but when I get out to LostPrairie I'll tell you some schtuff.
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
posted
I agree with Glenn. Sounds like trapped moisture.
On HDU, paint can only dry from the outside . Unlike wood, HDU is impermeable and the paint/moisture cannot be absorbed into it. I think you have to let the primer and the paint dry for a few days before exposing it to direct sunlight.
I think Gary Anderson just paints waterbased acrylic directly onto the HDU without priming. I haven't tried it yet but I plan to.
------------------ "The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed."
Albert Einstein
Failure to advertise is a lot like blinking in the dark. Nobody, but you, knows what you're doing.
posted
The guys could be right, but first tell me what the primer label says. I'm not farmiliar with that one. What was the cure time allowed for the primer?
Unless we want a dead, glass smooth surface, we never prime. No reason to. Not with oil base, not with waterbase. We've never had ANY experiences with blistering and painted HDU. Tell me about the primer.
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
posted
Pierre,,,,,, Are you saying that you do not prime your HDU signs??? I have toyed with the idea myself that it may not be necessary if using a good quality latex. I am sure others would want to know the results, also!! Expand on this one, please.
------------------ John Smith Kings Bay Signs 945 Haddock Rd. Kingsland, GA 31548
Purveyor of fine signage and Innovator of good things yet to be
www.kingsbaysigns.com
WoodCarver on mIRC chat
Posts: 817 | From: Central Florida - The Sunshine State | Registered: Jan 2000
| IP: Logged |
The reason the paint is peeling up is that the surface was not cleaned to perfection.
I use an air gun to blast it clean, and others use a pressure wash to clean it.
Moister is not the problem...why? Because the primer he used was water base....its already moist. Well, duh! (thats a joke everybody, not an insult)
There is no reason to primer HDU unless you just want to change the base color from tan to white so your top colors will be bright.
Otherwise paint the raw HDU with the absolute best 100% acrlyic latex paint money can buy (exterior house paints)and finsh coat with Pluecid Clear. (although the house paint will stand up alone...the Pluecid will make the finish rock hard.
See my article in the Febuary 2001 issue of Sign Builder Illustrated on page 40
------------------ Draper The Signmaker Bloomington Illinois USA
Get To A Letterhead Meet This Summer! See you there! 309-828-7110 drapersigns@hotmail.com Draper_Dave on mIRC chat
Posts: 2883 | From: Bloomington Illinois USA | Registered: Nov 1998
| IP: Logged |
posted
Thanks, Davey. You saved me some time. Super busy right now.
Davey said it all.
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
I haven't tried the no-prime technique, but if you can get acceptable results with less effort and expense, well, THAT'S a no-brainer.
I still have to figure out what went wrong. I always prep HDU like this: sand, vacuum, blow off, prime. This has always served me well in the past, just this time I've had problems.
Is puzzlement.
------------------
Posts: 237 | From: ft. collins, colorado,usa | Registered: Mar 2001
| IP: Logged |
posted
Hey, John. Nope. No primer. No need that I can see. All paints have a natural grip in the porous surface of HDU. If you want a dead smooth surface, a heavy bodied primer is the best way. For carvings of realistic items, aminals, peeples and things like that, a natural porous surface looks better anyway. We do have carvings that have both. A smooth, primed first area and a natural looking area. You don't need it, John. We depend on Pelucid for a weatherproof, permanent seal.
------------------ St.Marie Graphics & Makin' Tracks Sound Studio Kalispell, Montana stmariegraphics@centurytel.net http://www.stmariegraphics.com 800 735-8026 We're chiseling every day of the week! :^)
posted
I have very good luck with sherwin williams dtm on hdu and foam, no primer. DTM stands for direct to metal but it is an acrylic Bill
------------------ Bill & Barbara Biggs Art's Sign Service, Inc. Clute, Texas, USA Home of The Great Texas Mosquito Festival Proud Third year Supporter of the Letterheads Website MailTo:twobeesusa@netscape.net
Posts: 1020 | From: Lake Jackson,Tx | Registered: Nov 1998
| IP: Logged |
posted
I've said it before and I'll say it again. Blowing off the HDU with an air gun will NOT get all the dust off. There is enough static electricity for some of the airborn dust to jump right back on the sign. The dust sits back down into the open cells and heavy bodied primers will lay on top, unable to grip the sign thru the dust. If you don't believe it, blow off your sign real good, then take a garden hose and rinse it good with a squeeze nozzle on heavy stream. You'll see a color difference where the dust rinses off.
As the others have said, you don't need primer. Any good paint will stick to clean HDU.
I've gone a step further and it's working out great. I quickly sand the HDU blank with 220 grit sandpaper on a pad sander. Rinse all the dust off. When dry, I apply high tac rubber directly to the HDU. No priming necessary. I use latex stains for the background and TC resin for the raised areas.
Speaking of latex stains, this comes right from a major paint company's chemist. Latex stain is simply latex primer that is tinted.
------------------ Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 ICQ: 21604027 sherwood@up.net
Posts: 5397 | From: Crystal Falls, MI USA | Registered: Apr 1999
| IP: Logged |
I as well have experienced the problem you refer to for a short time period. Our shop went for years without a problem until a switch of primer brand. Then, the only time the problem would arise was with the use of that primer. Normally I would agree with everyone else’s submission about moisture; however, I was involved with the extensive trouble shooting of this problem within the shop and everything pointed back to the primer. For our production methods, we could not successfully get the Cooke primer to work.
Your second post mentions that you followed the same procedure as always. Did anything change from your normal operation; new primer, different air source when blowing off the piece, location of it drying, time intervals between each step? Obviously, the weather is a variable. Just attempting to understand what happened in this case.
Dave Sherby,
Agree 100% with your first paragraph as it relates to removing dust.
Pierre,
At my former place of employment, most of our non-blasted HDU signs had “glass” smooth finishes with a two-part urethane hi-gloss finish (LIMCO or Glazer). I was glad to see you mention that would be a time for a heavy primer. Of the jobs you’re doing now that call for such a primer, what is your preferred primer, and what others have you been exposed to and your opinions if you wouldn’t mind sharing? I am partial to Coastal’s FSC-88-WB. Never really fond of the solvent-based counterpart, but have nothing but praise for the water based.
Dave Sherby, I fully understand what you mean about the static electricity pulling the dust back onto the surface. I've been amazed more than once the way the dust will settle back on ME after I've blown that accursed stuff off. I must say, though, that I can't imagine enough dust settling back on the sign to create any great problems. Of course, this is coming from the guy who's having the problem.
As far as washing off the dust, that sounds like a good plan but, since the consensus is a moisture problem, how long does one wait until one can be sure the surface is sufficiently dry to apply the finish coats?
And as far as the Cooke primer is concerned, I'm rather inclined to suspect it. Except that it didn't fail all over the sign, and the sign was about 2 1/2' x 10'. The primer issue is moot anyway, since I don't plan to waste any more time on that phase of fabrication.
------------------
Posts: 237 | From: ft. collins, colorado,usa | Registered: Mar 2001
| IP: Logged |
posted
I think Brian and I talked about this already but here are a few more things to consider. It is true that most paints will adhere to HDU just like the splashes and drips adhere well to your clothes. The quality of the resulting finish is the concern. Acrylics adhere the best to urethane and the type that also promote good intercoat adhesion are preferred. Acrylics will also fill in the porousity of the foam. Also the acrylic primers which have no vinyls in them are sandable. My favorites are Chromatic and Precision Board, both in waterborne formulas. Your favorite finish coat will work over both of these, no matter what type of paint it is. The type of failure Brian describes is often found when the primer has not completely cured before the finish coat is applied. This can happen no matter what the first coat was, primer or finish paint. Dust certainly can be a factor as the first coat will bridge over the holes without adhesion into them. This produces a weak paint film as it is only adhered to the very narrow ridges. I have had the best luck with a combination of vaccuum and washing. Dry inverted for adequate drainage which will take about an hour here. Solvent based products for the first coat are problematic as they crater out with again a loss of adhesion inside the porous holes.
------------------ Kent Smith Smith Sign Studio Greeley, Colorado, USA kent@smithsignstudio.com
Posts: 1025 | From: Estes Park, CO | Registered: Nov 1998
| IP: Logged |
posted
I've allways vacuumed the board with our heavy duty wet/dry vac before priming and this seems to work very well at removing all the dust. Using an air gun to blow the dust off would seem to just recirculate the dust instead of removing it. Washing the board off would just add a step to the process that would require more waiting time. Using a good strong wet/dry shop vac gets all the dust off the sign and in a container ready to go to the dumpster, instead of just relocating it. Plus you don't have to wait for the water to dry, your ready to start painting or priming, depending on what kind of look you want the surface to have. I've had problems in the past with certain primers and paints not holding up so I now use Coastal Enterprise's FSC-88 WB primer as well Bob, and am extremely happy with it. I like the fact that Coastal not only makes the HDU board, but also offers other products that are specifically designed to be used with it. The only reason primer is used on HDU is to build the surface up and get it smoother. The FSC-88 is really thick and sands better than anything else I've tried, and it dries really quick. As far as paint goes we now use One Shot mainly, but will occasionally use Sherwin Williams Latex "Super Paint" brand. The One Shot paints just have a shine, or a wet look to them well after they're dry that I haven't been able to get with latex paints. Without actually seeing the sign it's hard to tell what happened since you did everthing the same as usual on it. I just thought I'd throw out some ideas on how I'm doing things and what products are working really well for me. Hope it doesn't happen to you again and that some of our thoughts helped.
------------------ Paul Keys Jr. Signs, Logos & More... Lynchburg Va. 1-(804)-385-1800 www.signslogosandmore.com
posted
Paul, I don't know what vac you have, but my big heavy duty ShopVac™ doesn't come close to removing all the dust. Here's how I discovered this. First I blew off the loose dust (outside) with an air gun. Then I vacuumed the panel with the shop vac. I even used a brush head to hopefully help sweep the dust up off the board. Then I took the panel out to my blacktopped parking lot and rinsed with a strong stream. There was a river of HDU dust clearly visible running down the drive. The time spent vacuuming was about equal to rinsing so I don't bother with the vac anymore.
When I stand the panel up in the sun, it takes less than a half hour for it to be totally dry. I have had no problem with anything not sticking to the HDU after it looked and felt dry.
True its an extra step, but having to repaint and sooth an irate customer is also an extra step I try to avoid. I can always find something to do while the panel is drying, like weed the rubber. After the panel is dry I put high tack rubber directly on the raw HDU, (sanded with 220) and blast. I have totally eliminated the primer and the drying time associated with it, so rinsing down my board adds little time compared to priming and waiting for it to dry.
I've heard some say that Coastal's primer has too many solids in it for SignFoam's smaller pores, that it bridges the cavities, but I would check with SignFoam before taking that as gospel.
------------------ Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 ICQ: 21604027 sherwood@up.net
[This message has been edited by Dave Sherby (edited July 22, 2001).]
Posts: 5397 | From: Crystal Falls, MI USA | Registered: Apr 1999
| IP: Logged |
posted
Dave, I use a Sears brand wet/dry vac. Not sure what model as I'm at home right now, but it certainly is not their biggest or their smallest they offer, somewhere in between. When we first started using HDU about 7-8 years ago I would blow the dust off with a hair dryer then wash it off like you do with a garden hose. It didn't take long for a situation to come up where it was snowing or raining out and I needed the sign done so we tried the shop vac and it seemed to do work. I then tested it later as you did, but found that the amount of dust coming off the sign after vacuuming it was very minimal. Been doing it this way for well almost 7 years now and never had a problem. For the past 3 years we have averaged 1-2 Precision Board signs a week. They have become our specialty of sorts. The problems I had with the primers were that they wouldn't sand very well and seemed too thin. I like the Coastal primer because it sands so well and is very thick, it also drys extremely fast, usually within 20-30 min. Not trying to argue the point, just stating what has worked for me for years now without a single problem, in hopes it might help someone.
------------------ Paul Keys Jr. Signs, Logos & More... Lynchburg Va. 1-(804)-385-1800 www.signslogosandmore.com
posted
Paul, If you are not getting dust off after vacuuming...GREAT. I agree Coastal's primer is great for sanding and getting an ultra smooth surface. I use it for carving and now that my supplier carries PB I can use it in confidence. Like I said earlier, I heard that PB's cell structure is more open than SignFoam and will accept Coastal's heavy bodied primer better.
You should really check out TC Resin. It is so cool and really speeds production and sign quality.
------------------ Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 ICQ: 21604027 sherwood@up.net
Posts: 5397 | From: Crystal Falls, MI USA | Registered: Apr 1999
| IP: Logged |
(thats a joke everybody, not an insult)
Printer-friendly view of this topic