New paint problem

[Russell Reay]

After a long period of inactivity, I was finally able to put a top coat on my fenders. This is on top of two coats of Evercoat building primer, and two coats of Duplicolor gray primer. My topcoat is single stage urethane mixed 8:4:1 and applied with an ordinary auto spray gun (not hvlp) at 35 psi. I applied three coats. After seeing the disappointing result, I searched for the product data sheet, and see that my only deviation from instructions were that I should have sprayed at ~25 psi. The photos are accurate depictions of how the fenders appear in reality. My rear fenders came out much better, with very few patches of flat finish. I am not a skilled painter (duh!), but would like someone who is to tell me what I did wrong. I can always buy more paint, but prefer not to repeat the mistakes.

[jb-ob]

Not easy to tell from your photos.

I'm not a fan of cheap rattle can primer. It appears one of the two primers reacted with your top coat. I'd skip the DupliColor and instead use an overall epoxy primer/sealer before top coating.

[Russell Reay]

I agree re: rattle can stuff. The Duplicolor was the only primer O'Reilly's had in quarts. Instructions were to thin w/ Duplicolor Specialty reducer 1:1. I used the Crossfire reducer on the assumption that all reducers are the same.

[brito36]

I agree with the two previous people on the Barn. I have been a painter for most of my life, and I would have gone with the manufacture's procedure. With all the new paints along with product changes, it is important that you follow the maker's procedures. I would not have used a rattle can primer.....

[Jumbogem29]

You are ok on 35 psi you could go to 40 psi will not hurt a thing. Yes you had a reaction with your primers .

[Will N]

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How was the humidity when you sprayed the paint? I've gotten dullness like that when I sprayed paint on a very humid day. I'd bet you might be able to polish them to an acceptable finish.

[Tinbasher]

You've had a reaction between the primer and top coat. Sand it out and get ride of the reaction. You may have to go down past the spray bomb primer. Finish with 400 grit paper, Apply a coat of sealer with your gun and then top coat. Worth a try. If it reacts again stop.

[47topless]

As it's being applied, you don't want the paint to dry between the spray gun and the surface being painted. The temperature in your shop and the PSI, at the gun, must be correct. Spray painting, in a shop that's too warm, and a PSI setting that's too high, is always problematic.

[J Franklin]

How humid was the air in the shop? I don't remember if you answered that question. It looks like humidity was your problem. I agree with Will N, take a small area and use some polishing compound first before condemning what you did.

[Thodge]

I’m wondering what the timeframe was between primer applications and topcoat application. When you say two coats of the Evercoat primer, were the fenders block sanded smooth after that? You’ll always get a better finish with better gloss holdout by using a catalyzed primer, letting it cure, block sanding, then going right to your topcoat without any sealer. That is as long as there are no burn throughs in the primer. The non-catalyzed Duplicolor primer would certainly act up if you applied it as a “wet-on-wet” sealer without curing before topcoat application. I’d sand them down to the Evercoat primer, reapply more high build primer then block sand it and put the urethane right over that.

[bobbader]

Agree with all said so far, but I note that the reducer can says "cool reducer".
If you've done this job in the current northeast heat, this could tend to allow the paint to "set-up" too quickly and cause dry spots. There should be mid-temp or high-temp reducers that might help your paint flow. I also agree that 40psi would not be a problem ................ might actually help ........ but practice on something else if you're going to increase pressure. Then, remember to focus yourself (not over focus and rush). Get yourself a pace that works for the expanse of the item being sprayed. Good luck.

[rotorwrench]

There are a lot of pitfalls with painting now days. I missed Deltron after I had to change to Imron. I then missed Imron until I could finally get PPG Concept. Now I miss the Concept since it is no longer available. Sherwin Williams Acry-glo & Jet-Glo are now harder to get & way expensive so I'm using TCP acrylic urethane but it is real finicky. Gun pressure, distance to surface, and gun flow adjustment have to be just right with a super clean surface or it gives problems. It uses three different temperature reducers as well but even that stuff is expensive now. I try to get by without it if I can but then I have to wait for perfect temperature and humidity conditions. Painting used to be easy but it's not so much anymore and especially if you want to use single stage paints.