The Stovebolt Site Forums The Shop Area Paint and Body Shop Minimum Painting Temperature

This seems like a crazy simple question, but I've spent the last two hours searching this site and the web with no luck. I'm painting my truck with PPG Shop-Line JAU Acrylic Urethane. What is the minimum ambient air temperature for painting?? The high temperature in Redding today will be about 55F. Will a get acceptable results?

There is no information on the paint can, the project data sheets, or the PPG website; which I find to be amazing considering how much paint PPG sells.

I don't know about your fancy paint, but I know regular old oil paint won't cure, and or set down properly if it's under 40F. I think more temp would be advisable. I also think someone else with more knowledge will chime in.

Nope, 55 is no good. 70 at least.

I agree and remember it is the metal temp along with the air temp. gat a cheap laser temp gun to check. you will be supprised the difference in temps.

Most paint manufacturers recommend 70f or above if I remember right. Having said that I've painted in the 40s but got more than average orange peel when doing so.

Here is a couple of things. First look at the can of paint. Try to peel the seem away. Usually there is a wrap and a half of label on the can. The hidden part of the label has the information for the paint. Flash times, temps, ect. Or you can go to the PPG website. It is a real pain to navigate, but has all the info you need on the paint you have, including recommendations, and the MSDS sheets.

I checked the cans, the MSDS, and the website. There's enough safety information out there to make me nauseous, but nothing on recommended application temperatures. 70F seems like the right answer, but I wish I could find something from the manufacturer.

Click the contact us link. Nothing like getting it from the horse's mouth.

click Is this what you found? Follow the tech info link, it gives drying times @ 70deg. Doesn't give min. temp, but I would hold out for at LEAST 65-70 with low humidity, the colder it is, the faster the reducer.

Check with your paint supplier for the MSDS sheets.
Urethane need a minimum temp during the crosslinking period to cure properly.
If you try to paint at too low a temp. you risk having the paint remain soft , nothing you can do once that happens,just strip it off.
Also, urethanes should have sufficient air flow across the surface during drying to insure that solvents aren't trapped causing solvent " popping" which resemble blisters in the surface.
All in all it would be best to wait for the temp to be at least 70 for spraying.
It will save a lot of time (and money) in the long run!

I contacted PPG by e-mail because a phone number was not provided for this product line. My question was very specific, "What are the minimum and maximum air and surface temperatures recommended during spray applications"?

Their answer was, "All PPG products are tested at 70F".

Of course, this doesn't answer my question. I still don't know if 60F or 80F will yield acceptable results. Next stop is to ask the guys who sold me the paint. Maybe they know.

I recall reading that epoxy and urethane paints will eventually cure/set at as low as 50 degrees F; however, the lower the temperature, the slower the set; and, the slower the set, the more chance of dust, etc settling-on and setting-in the paint.

I think you will find that a manufacturer will recommend 70 degrees F and low humidity for best results. They will most likely not give a low temperature limit for guaranteed "acceptable" results. The same would be true for acceptable higher temperatures - if the paint sets too fast, multiple coats might not adhere properly (however, perhaps a higher temperature reducer could be used).

Where is MARTINSR? He'd have a good answer, from a pro.