Poor Urethane

pat sublett · Oct 9, 2013

I purchased acrylic urethane paint from RESTORAL SHOP on the internet. I also purchased epoxy primer from them. The primer seemed to be fine, very smooth and easy to paint. The urethane did not look right, very thin. I think reducer would have thickened it. I used the same gun (standard siphon) that I used to apply the epoxy primer. I could never adjust the gun to even put on a very light coat smoothly. I switched to a HVLP gun with the same results. I guess I will go to tractor supply and buy some sorry paint to get it done.

RandyB(MI) · Oct 9, 2013

There are plenty of "scammer" companies out there to prey on the unsuspecting bargain hunter. No one will ever challenge a company for assigning the title " acrylic urethane" or "hardner" etc to any cheap watered down product and they know it. One gets what one is willing to pay for and no more. Unfortunately there is no "standard" they must meet like an engine oil does. There's a reason PPG , Dupont,BASF etc are high priced. Quallity, longevity , stability,uniformity, product support and education to name a few.How many posts do you see on here asking about problems with those brands?? You never know what you are getting or who makes it or what to add to it or what to harden it with etc,etc. There's a reason for this. Liability. The big companies give you real directions , real material safety data sheets , each mixing ingredient and amount and the products designed to be used in conjunction for a top drawer result.And they stand behind their products if by chance there is a problem.You can go cheap but you're dealing with the devils of the paint industry.

pat sublett · Oct 10, 2013

Went to town today, got some Martin-Sanour CrossFire and got my project painted. I should have known better. Live and learn and learn and learn.

Brad_bb · Oct 11, 2013

It's also important to know that epoxy sealer primer is easier to shoot than the paint. If you try to paint with a full coat like the epoxy, you'll run the paint. the trick is to first apply a fog coat. Your not trying to get coverage. Just a fogging where you will still see most of the primer through the fog coat. This fog coat will help keep the next coat from running. It gives the next coat something to grip to.

So you spray the fog coat, let it set up for 5-10 minutes, maybe 15 if you have no air movement. The trick is that you want that coat to still be tacky when you shoot the next coat. Your next coat after the fog coat will be a medium wet coat. Wait 10-15 minutes for it to tack off, and then shoot another medium wet coat. Don't over do it, or you'll run.

pat sublett · Oct 11, 2013

I have not painted a lot of urethane but, painted my first very succesful in the early 70s with Emron. The paint that I got on the internet was defective.

CNKS · Oct 11, 2013

You don't need fog coats with urethane. I have never done that in 10 years. That is reserved for alkyd enamel, although I suppose it doesn't hurt anything. I have never tried it. I'm not too concerned if the first coat does not get good coverage. The second coat does, the third coat is insurance. Skilled painters only use one coat. Runs with urethane or epoxy are caused by spraying too close or two slow. IMO, the previous coat has little effect unless you wait less than 10 minutes. My opinion based on my experience with PPG. My runs are usually on sharply curved surfaces when I get the gun too close.

Brad_bb · Oct 11, 2013

Keep in mind that I'm talking about single stage DCU. I always fog coat on DCU. I would definitely advise a novice to fog coat in order to reduce the chance of running. As they get more experience, they will discover for themselves whether they could shoot it a wet coat or have to fog coat. If you really want to frustrate a novice painter, have them not do a fog coat and run the crap out of it, and then see how enthusiastic they are about it.

Jason S. · Oct 12, 2013

I'm with CNKS on this one...a tack coat or fog coat as you called it can cause more problems with today's faster curing paints than it helps. If you put on a tack coat with some of fast curing urethanes out there it will cause bad orange peel because you can not get the second coat you put on to flow out the tack coat that you put on. In the days when the paint mixed 1:1 with reducer yes you could flow it out but with today's 4:1 and 8:4 ratios you do not have the solvent in it to help flow it out. I was told several years ago by the RM rep to paint like this..." put the first coat on like you want the last coat to look"

Poor Urethane

pat sublett

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RandyB(MI)

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pat sublett

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Brad_bb

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pat sublett

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CNKS

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Brad_bb

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Jason S.

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