posted
I used to use Coastals FSC-88 waterbased. I had a really hard time getting it smooth because it is so thick. Good for filling I guess. Some on here claim it is the best for smooth finishes but I just didn't like it. I have since switched to Jay Cookes. It's rolls on really well and all of my stuff has been smoother.
Some folks aren't using primer at all. There was an article in one of the recent magazines (I can't recall which one) where the guy said they never use primer unless a really smooth surface is needed. The HDU will take paint without primer. I am considering that option as well if for no other reason than saving time.
Hope that helps.
-------------------- Amy Brown Life Skills 101 Private Address Posts: 3502 | From: Lake Helen, FL, USA | Registered: Feb 2001
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posted
Hi Amy, that's what I thought, that the hdu would take paint, but guess what? It does not. I have several blanks primed and sealed with 1shot and when I went to remove the resist all the paint came right off. I used a high quality Acrylic latex primer, but it did'nt work at all.
-------------------- "Keep Positive"
SIGNS1st. Neil Butler Paradise, NF Posts: 6277 | From: St. John's NF Canada | Registered: Mar 1999
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I use latex primer for HDU. It's what I have on hand and does the job. On large signs, I've even sprayed it, boy was that a lot easier than dobbing with a brush.
I've painted OneShot directly onto HDU without primer and wasn't happy with the color or the sheen, too porous.
I've primed before applying the sandblast mask and had the same results as you mention. I've since given up on that hassle and apply mask direct onto the HDU, works just fine.
I finish with latex and/or OneShot.
Enjoy, Cher.
[ June 11, 2002, 03:48 PM: Message edited by: Cheryl Lucas ]
-------------------- Co-Host: SANDCASTLE Panel Jam 'a Dixie Letterhead Reunion' Fort Myers, Florida
Cheryl Lucas a/k/a "Shag" on mIRC Vital Signs & Graphics, Etc. Cape Coral, Florida 239-574-4713 VSignsNgraphics@aol.com Posts: 987 | From: Cape Coral, FL USA | Registered: Aug 2000
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-------------------- Mario G. Lafreniere (Fergie) J&N Signs Winter did show up! Posts: 1257 | From: Chapleau, Ontario | Registered: Jun 1999
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There isn't enough information on your posts to give you a proper answer, so please bear with me as I ramble....
How aggressive was the adhesive on your mask? For pre-painted boards, I used a medium tack rubber mask. For raw HDU, I use high tack.
I've had a real problem with using water-based primers when it comes to sandblasting pre-painted boards. The primer just doesn't bond to the surface enough when I pull the mask off no matter how careful I am. When I switched to Coastal Enterprise's solvent-based FSC-88, I had absolutely no bonding failures between the primer and the HDU.
Lately, I've just been applying high-tack mask to raw HDU, sandblast, remove the mask and spray the panel with a quality latex paint. Then I use my quills or flats to paint the letters with OneShot.
[ June 11, 2002, 06:23 PM: Message edited by: Glenn Taylor ]
posted
Well Fortunately I did'nt have all the resist applied, I tried only one. What I did was I primed the HDU with 3 coats of a good quality latex primer, then I applied 1 coat of 1 shot as a top coat, doing this I thought I'd save time when it came time to paint... And like Jannette said I was going to prime and paint the blasted areas befor removing the resist. I just finished priming the boards (backside) with the recomended precision board primer, I have 2 coats on and before I go tonight I will prime a 3 rd time. I will then try to apply the resist on the primer only. I'm thinking that maybe I had too smooth and slick of a surface and the resist was a litlle to aggressive... Hmmm do you think that's possible?
-------------------- "Keep Positive"
SIGNS1st. Neil Butler Paradise, NF Posts: 6277 | From: St. John's NF Canada | Registered: Mar 1999
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posted
Gee Glenn we must have been typing at the exact same time... I think you hit the nail on the head.... the last time I used resist it did'nt have nearly the same tack... this lot I just bought seems to be very strong.. and having to order from out of province you always don't get what you want. So I'm hoping that applying the mask directly to the latex primer should work. By the way what do you guys recommend for air pressure and blast, I'm going to outsource this part,
-------------------- "Keep Positive"
SIGNS1st. Neil Butler Paradise, NF Posts: 6277 | From: St. John's NF Canada | Registered: Mar 1999
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What Glenn posted could be the problem. It can also be that the HDU is still dusty before you prime it. Sometimes I was it out with the hose first. Even after vacuuming it off with the shop vac you can see the dust come off.
The last few signs I have blasted I used the Jay Cookes (two coats) and then masked that and blasted. I then left the mask on to paint the interior sections. The problem I found with that was the paint build up on the edges. I ended up having to cut all the excess paint off with an exacto knife to get it to look decent.
I have heard good things about the FSC-88 oil based stuff. No one carries it around here. I need to order a sample.
Who knows what it is?????
-------------------- Amy Brown Life Skills 101 Private Address Posts: 3502 | From: Lake Helen, FL, USA | Registered: Feb 2001
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posted
yes Neil ... I do think that is possible. The smoothness of the paint, coupled with the heat of the blast could make the resist stick too much and pull the paint right off.
I'll mention that I use medium tack rubber when I use the pre-prime method ... don't use the high tack stuff! And I only prime, not paint before the mask and the blast. I do however prime and paint before stripping the mask. One thing that will occur when you strip the mask is that a skin of paint will stick out around the edges of the lettering, borders and whatever else was masked. I just palm sand it off before painting.
Hope I made myself clear ... it's how I do it, (not necessarily the "right" way) and it seems to work for me okay.
posted
Thanks Cheryl, Mario, Glenn, Amy, Jannette, I hope I did'nt leave anyone out. Yes it is #116 so I don't know which one that is. When You all come to Newfoundland I'll take you out to see the Icebergs, we'll chip off some Ice and use that to cool our Margauritas.. ahhhhhh or our Newfie Screech!
-------------------- "Keep Positive"
SIGNS1st. Neil Butler Paradise, NF Posts: 6277 | From: St. John's NF Canada | Registered: Mar 1999
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I don’t know what the “best” is, but put me down for a vote in the Coastal FSC88-WB column if priming is to be done without a urethane agent
-------------------- Bob Gilliland InKnowVative Communications Harrisburg PA, USA
"The U.S. Constitution doesn't guarantee happiness, only the pursuit of it. You have to catch up with it yourself." Benjamin Franklin Posts: 642 | From: Harrisburg, PA, USA | Registered: Nov 1998
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A few years ago someone posted on here to use a latex wood filler on HDU, the kind of wood filler that is creamy and comes in the little plastic containers that look similar to Yogurt.
We tried it. We like it.
The HDU must be dust free, so vacuum it, wash it, or whatever it takes. Spread the creamy latex wood filler with a vinyl squeegee over the areas wher the stencil will sit. Apply stencil, blast, then paint the entire sign with 100% acrylic latex house paints...the expensive ones and flat sheen. No primer is necessary. Why? Because primer does not soak into HDU, it sits on top and serves as no better bonding than the finish coat.
If you want a gloss sheen, then use gloss clear coats of 100% acrylic latex over the finished sign. You might want to try Pelucid as a clear top coat.
The only reason to use a primer is to kill the natural color of HDU from showing through on a light color background. If you are painting the sign a forest green background, for instance, then there is no reason to use a white primer, it just makes no sense to paint the sign white then paint it a darker hue.
With HDU you must think "out of the box" when it comes to paint.
posted
When I get the HDU cut to size, I use an airhose and blow it off good. I then prime with Ace Royal latex primer. I use medium tack anchor sandblast stencil and have yet to have a problem. Like Nettie, I prime, apply the stencil, blast, and then prime the blasted areas before removing the stencil. I use all latex paints for finishing though.
-------------------- Maker of fine signs and other creative stuff. Located at 109 N. Cumberland ave. Harlan, Ky. 40831 606-837-0242 Posts: 4172 | From: Ages-Brookside, Ky. Up the Holler... | Registered: Jul 1999
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posted
If the mask is too thin & non resilient, it can cause a slight pulverization of the underlying hdu surface, which can result in the lifting of the pre finished surface when removing the mask.
I like Chromatic 1010 high-build acrylic.
-------------------- Steve Purcell Purcell Woodcarving & Signmaking Cape Cod, MA
************************** Intelligent Design Is No Accident Posts: 900 | From: Cape Cod, MA | Registered: Oct 1999
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posted
Neil, most of this has already been mentioned but this works for me.
1 After sanding, I blow it off thoroughly with compressed air.
2 Wash it with a strong stream of water and allow to dry.
3 I prime larger signs by thinning FSC 88 WB and spraying with an HVLP gun. This gives a super smooth prime. On smaller signs I spread it on with a squeegee, straight out of the can.
4 Allow to dry and apply a second coat if needed. Don,t sand between coats.
5 Sand with 220 and then 400 wet dry paper. It's ready to sand when it doesn't gum up on the paper,
6 Keep the blank in front of a fan until ready to topcoat. The friction of the air blowing over it will make sure it's thoroughly dry and that airborne moisture doesn't re- enter the primer. Topcoat with three or four coats of acrylic latex. use thin coats
7. Let it cure from 5 to 7 days depending on humidity. If the paint isn't completely dry the trapped moisture could try to vaporize and escape which will make the paint blister and peel during the heat of the blast.
8 Apply Anchor #153 computer stencil It's medium tack.
9 Blast at about 80 PSI with fine sand. As Steve said, too much velocity and sand which is too coarse will actually pulverize the bond of the primer to the substrate.
10 Leave the stencil on and spray the background with acrylic latex solid color stain. Two or three coats. The stain acts as a primer, gives a flat finish, and is very durable.
11 peel the mask. The ridge left by the solid color stain can be removed easily with the fingernail.
-------------------- 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
I used to have paint lifting until I started hitting the HDU with a hard stream of water. The dust is difficult to remove. Static wants to suck it right back onto the board. I can't wait to try the new SignFoam. The dust problem is suppose to be greatly reduced with the new stuff.
DON'T try to prepaint the entire sign to the finish coat like you can with redwood. It is very difficult to get all the paint to be very even. When you start blasting, any area of paint that does not blast off at the exact same rate ends up leaving a high spot. Its almost impossible to even out the high spots.
I use high tack rubber on raw foam. After blasting (I blast at 75 lbs.) the background gets 2 coats of latex stain. Right after staining, I remove the rubber and paint the edge of the sign with straight One Shot. The next day I remove any "flags" of stain that dried up the sides of the rubber. Then I mix up some SignShine resin, add my One Shot paint in the proper ratio, apply to the raw foam and spread to the edges of all letters and graphics. Next day I mix some more SignShine, mix in the border color and brush a thin layer on the edge. This really toughens up the signs edges. All that's left is to paint the back side. The SignShine Resin is ultra smooth and has a nice gloss. You can paint over it with One Shot for special effects, fades etc., and it is great for gilding.
[ June 12, 2002, 10:15 AM: Message edited by: Dave Sherby ]
-------------------- Dave Sherby "Sandman" SherWood Sign & Graphic Design Crystal Falls, MI 49920 906-875-6201 sherwoodsign@sbcglobal.net Posts: 5407 | From: Crystal Falls, MI USA | Registered: Apr 1999
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