Paint and humidity
Thread Starter
Pro
Joined: Jun 2009
Posts: 613
Likes: 3
From: Fleetwood PA
Paint and humidity
I'm really getting anxious to paint my 68.Got the primer on and sanded and ready for color, but here in PA it's been ridiculously humid for the last 2 weeks.( about 80% or more) 
It's supposed to get a little better in the next few days,and I know the lower the better, but what would you say is the max humidity that you should paint in?
It's supposed to get a little better in the next few days,and I know the lower the better, but what would you say is the max humidity that you should paint in?
Drifting
Joined: Aug 2005
Posts: 1,289
Likes: 3
From: East Waterboro Maine
Do the manufacturers specs say anything for limitations? It seems there should be some guidelines on their tech data sheet.
I've heard some folks say 70% or less is safe. Make sure you have a good line dryer on your compressor though.
I've heard some folks say 70% or less is safe. Make sure you have a good line dryer on your compressor though.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
I shot one in black lacquer and had it looking really slick, got the hell out of the garage before I did something to screw it up and came back in about an hour. It had turned completely gray, I just about fainted. Called a buddy of mine and he said the humidity was too high for the thinner I used. He said the humidity was trapped and told me to respray the car with thinner and this would open the paint so the humidity could escape. I did it and it worked. Just sharing.
Melting Slicks
Joined: Jun 2009
Posts: 2,709
Likes: 3
From: Savannah GA
If you're unable to wait for the cooler, drier early fall weather coming up next month rent a climate controlled booth. This will get rid of any "blushing" concern you might have, and you will get the added benefit of mosquito and leaf free topcoats. Bugs seem magnetically drawn to the final coat of backyard spray jobs! Also carries the added benefit of baking the finish to accelerate the cure... you can reassemble more quickly with less fear of smearing uncured paint.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
Humidity here is almost always over 80%, but we have the heat to go with it and with the proper reducers etc, we have little problems.
Blushing has as much to do with the dew point as humidity.
Renting a booth is always best, use the right products for the conditions, allow extra dry time if wet sanding and follow the directions for flash time between coats.
Do a test if you can first.
In the old laquer days we used to add retarder to the mix and avoided blushing, but if the prep wasn't perfect, it caused other problems.
Blushing has as much to do with the dew point as humidity.
Renting a booth is always best, use the right products for the conditions, allow extra dry time if wet sanding and follow the directions for flash time between coats.
Do a test if you can first.
In the old laquer days we used to add retarder to the mix and avoided blushing, but if the prep wasn't perfect, it caused other problems.
