Automotive paints and relative humidity. Say wut?

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I wouldn't ever get down on anyone for clearing under the hood because if you are using a 2 stage system you have to clear it or it is not only matte in shine but the color isn't correct until you clear it. With metallic paint, clear is the way to go because getting it stripe-free and shiny is not easy with a single stage.

But that said, getting back to the OP, I guess humidity is kind of a mystery when it comes to speeds...
 
Spray water based base coat. You live and die with humidity. Every body shop I've ever sprayed in has a temperature and humidity clock near the booth.
 
Here is some info.

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67Dart440GT said:
Here is some info.
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The Sikkens Autowave system is waterborne. My question is in regards to solvent based with hardeners that require humidity to harden, however the paint companies do not provide guidance on minimum or maximum relative humidity levels nor how humidity affects the speed of reducers and activators.
 
ACME SS said:
The Sikkens Autowave system is waterborne. My question is in regards to solvent based with hardeners that require humidity to harden, however the paint companies do not provide guidance on minimum or maximum relative humidity levels nor how humidity affects the speed of reducers and activators.
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Yes. I use autowave every day. What specific information are you wanting from a paint manufacturer in regards to solvent, humidity, and how is it going to affect your day to day operations?
 
OK so today the temperature is around 90* but the humidity is 25% RH. I have done some research and found that below 40% there can be some issues with the paint not hardening up quick enough due to the lack of moisture combining with the isocyanates in the hardeners.

I stopped in a autobody supply store today in Boise, Idaho and asked the guy behind the counter about low humidity and he was quite helpful. He said they sell a BASF paint and a couple other brands and that 2 of the brands they sell have an additive which can be added to compenste for low relative humidity...Bingo!, I'm not insane. I told him that I had problems with runs and sags on a hot day using the same gun and technique I have used my entire life and he said that you need to spray 2 medium coats for each wet coat you would normally spray. He also said it depended on if you are using a high or low solid clear.

So since I already have my paint purchased I will do my best with what I have. I don't see the humidity going up or the temperature going down for months out here.

Thanks for following this, I used to live in Minnesota and had the high humidity issue...never thought low humidity would be a problem.
 
If you have a humidity gauge in the booth, have you tried wetting the floor pretty good to see if it will bring it up to, or above 40%? You could play around with it before spray time if it does. Just a thought.
 
ACME SS said:
I used to think you couldn't and perhaps PPG and Martin Senour, etc do not but....my secret money saving supplier has it.
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That is good to know, I always liked painting with acrylic enamel, heat it up on a hot plate, and shoot it.
It will flow nice and smooth.
 
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