I always seem to think of this stuff after the stores close, so here goes:
I'm getting ready to paint a car and the weather is getting colder. I've painted in 65 degree weather before with no ill effects. I've painted in a closed shop with a kerosene heater as well. That brought the temps up from 45 to around 60-63 degrees. the humidity here is fairly low but it may not reach 65 again for a couple of months.
I have a medium reducer that is rated from 65-80. I'd like to spray the car soon.
What happens if the weather is too cold? Does the paint not atomize well, leaving speckle & spatter like undercoating? Does the paint not flow out and lay flat? Is there an issue with diminished gloss? Maybe there is an issue with the paint sticking well leading to peeling?
I still have small portable heaters I could use. I'm just looking for a few pointers. Thanks, Greg

here are a few problems i can think of if it's cold when you paint.


you can get paint runs, it will flow out to fast.

it will take much longer for the paint to flash between coats.

the paint will cure much slower than normal. if it's to cold, lower than 50* paint catalyst sometimes stops working.

along with poor cure it will chip easily and not have proper durability.

after you have completed the job, 3 or so months later, when the temp warms up, you paint will probably start to dye back, loose gloss. you can buff it again but it will never really shine like it should.

What I've been told in numerous paint certification classes is catalyzed paint needs 70 degrees to properly crosslink and fully cure. That being said I've painted in the 60's plenty of times with no problems. I would just wait until the warmest part of thee day and have the coolest temperature reducer and or hardener.

Two years ago I painted a '63 ply in black urethane, low '60's temp. The paint never hardened. This was nice straight black job that had to all come off,re prime....start over. something to consider...

It is not just the ambient temp, but the temp of the Mass being painted,
IE: 60 in the shop may equate to 50 degree mass or less surface temp.

Find a heated shop, let it sit for a week or MORE. Then a month or two before being moved to a colder environment

The last time I painted in cold weather, I put three heaters in the shop in a triangle pattern around the car. Here is that car:

Brother in Law's 72 Duster. He likes the look of shaved marker lights and having no trunk lock.