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Low air flow environment

#1
Since it's winter, I'm doing a lot of work in my garage and getting a lot more runs. It is heated but doesn't have a lot of air movement. I.E. yesterday it was 70 in the shop and I used Euro with regular act, and 885. Today, I got to sand out some runs. With the lack of air movement, should I have gone with fast and 860 or maybe 870?
I think I know the answer but want to have it verified.
 
#3
Airflow through the booth shouldn't cause runs. My guess is that you are not waiting long enough on your flash times. In colder temps and using the 885 you need to watch the clear to make sure it is done flashing before shooting the next coat.
 
#4
Runs made the grand entrance on the first coat. It took 20 min for it to flash. I figured if there was some air flow it would facilitate moving the solvents out and it would flash faster resulting in reduced flow. I haven't used Euro much, so I haven't figured out the right products to use yet.
 
#5
Runs made the grand entrance on the first coat. It took 20 min for it to flash. I figured if there was some air flow it would facilitate moving the solvents out and it would flash faster resulting in reduced flow. I haven't used Euro much, so I haven't figured out the right products to use yet.
You probably shot it too wet for the temperature at the time. Did you spray at a slightly lower pressure as well?

I’ve been there where I forget to account for colder temps with even a med speed activator and get a small sag or run in the first coat, shooting at a decently high pressure.

When I do a 50/50 blend of fast and medium for the first coat I can lay it down slick enough without runs. So probably the 885 is what got you in trouble if sprayed on the heavy side.
 
#6
I was at 30psi. I should have gone with fast and 870. It was just a 1/4 panel. Upside is that the runs sanded out great!
 
#7
Yeah, I think 885 is probably just too slow for that scenario. I would think Normal activator and 870 would be about right, maybe with a splash of 885 in place of some of the 870 on the second coat, depending on how it's laying down.
 

Dub

Von Dub... The Total Gearhead
Staff member
#8
I will bet seeing you normally paint outside that the lighting in your garage is poor. I've never gotten runs spraying outside. Inside is another thing tho.
 
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