I'm just finishing up a sandblasted cedar sign for a local church, and I'm wondering if I should coat it with frog juice.
I finished the blasted part with an exterior latex stain. The edges and the back are exterior latex paint, and the details are one-shot & vinyl. (I added a bit of flattening powder to the one-shot)
I used latex products, as I'm told they "breath" better than oil on this type of sign. I want it to be as maintenance-free as possible, but wonder if adding a clear coat might defeat the purpose of using latex.
Any comments or advice?
Suelynn
-------------------- "It is never too late to be what you might have been." -George Eliot
Suelynn Sedor Sedor Signs Carnduff, SK Canada Posts: 2863 | From: Carnduff, SK Canada | Registered: Nov 1998
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We clear coat our sandblasted signs all of the time. But we use PPG DAU 75 clear and wet look hardener. I then have to add a few drops of the hardener to my one shot and let it dry completly before we clear it. Also I am right now experimenting with using this clear over laytex paint. I should be able to clear my test peice tomorrow and I will let you know what happend.
If you look at the parrot sign at the portfolio bullboard. I clear coated this sign completely front and back it has been outside for a while now and it still looks new.
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Flattening Powder? SES, what is it? inquiring minds...I've used Corn Starch to flatten O.S., it sort of works.
I stay away from clears as much as possible, having never found one that outlasts the other paint itself. Maybe the urethanes hold up, I don't know. We have the sun to battle with here. Frog J lasts about a year at the beach, I've gotten 7 or 8 years out of marine spar varnish at the same location.
Posts: 1859 | From: / | Registered: Nov 1998
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Scot, Thanks for the info. Is that an automotive clear? I've already painted the sign, so it's too late for me to add anything to the one-shot. I went to the portfolio page and I can't see the pic of your post. Sounds like it was nice though.
Hi Mikey!
It's called universal flattening powder & I got it from Canadian Signcrafter Supply. I think it is for screen printing, but you can add it to one-shot or even frog juice to flatten the shine. It is white powder, so maybe it is just expensive corn starch? I think the ratio is 1 oz flattener to 8 oz of paint.
I've got mixed feelings about frog juice. I have it on a couple of aluminum painted signs and it looks great. I used it to do an airbrushed fade on vinyl on my van, and the side that faces the sun looks like crap. I've never used it on wood like this and I was a bit afraid it would crack if the wood expands and contracts.
Sue
-------------------- "It is never too late to be what you might have been." -George Eliot
Suelynn Sedor Sedor Signs Carnduff, SK Canada Posts: 2863 | From: Carnduff, SK Canada | Registered: Nov 1998
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Yes, I have used clears on sandblasted signs with great success. Earlier with automotive urathanes and recently with Pelucid. Pelucid is kind of tricky to work with, it sets-up real quick and jells up if not repackaged into smaller containers and refrigerated. But it is an extremly durable one part clear you can brush on, or spray. Moisture actually makes it harder. Cheers
-------------------- Rob Thomas 3410 Ketcham Ct Beautiful Springs FL 34134 Posts: 965 | From: Bonita Springs, Florida USA | Registered: Feb 2000
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Yes it is an automotive clear and I used the same clear to clear my whole truck and it still shines like new (when there is time to wash it) All of the automotive clears are very good at UV protection it seems I used House of Kolor by Valspar to clear some signs and it does a very nice job but it cost a little more. I have also noticed that if I clear a finished duron or mdf board wich is what we use for realtors that they last a lot longer. duron has a tendancy to swell when it gets wet so the urathane does a great job keeping the water out. Our shop does charge extra for this depending on the size of the sign.
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I have never used any type of clear on my sandblasted signs. My procedure is basically the same as yours - latex paints for the majority of the surface, with some vinyl lettering, and occasionally one shot (mainly under gold leaf).
There are signs still up that I did 15 years ago that still look good. In my opinion there is not a clear that will outlast the paint underneath. I will admit that I haven't tried some of the newer ones.
-------------------- Chapman Sign Studio Temple, Texas chapmanstudio@sbcglobal.net Posts: 6306 | From: Temple, Texas, USA | Registered: Nov 1998
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Hi SL, I wouldn't recommend clearing the sign, unless it's a natural or oil-stained finish. The exterior durability of the latex is no less than if you painted your house with it, and the painted sign without clear will age more gracefully. If the customer gets 8 or 10 years out of it, then sell him a new one. No sign lasts forever.
-------------------- www.signcreations.net Sonny Franks Lilburn, GA 770-923-9933 Posts: 4117 | From: Lilburn, GA USA | Registered: Feb 1999
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No clear here.But I do double coat both backgrounds and letters. Latex on bgds. and one shot on letters. Have thought about clearing just the letters once in a while, mainly for UV protection. Also I agree with the theory about the paint having to breath with the wood, so it seems like clear would clog it up somehow, although others say it works OK.....
-------------------- Jeff Ogden 8727 NE 68 Terr. Gainesville FL, 32609 Posts: 2138 | From: 8827 NE 68 Terr Gainesville Fl 32609 | Registered: Aug 2002
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I think the ratio is 1 oz flattener to 8 oz of paint.
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