Humidity and Primer

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Well-Known Member
Nov 16, 2015
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So I know that one of the things that comes up pretty regularly is "don't paint if it's humid".

There was a Dense Fog Advisory this morning, showers later in the week. I'd love to get at least a coat of primer on this week so I can sand it and kind of see how much work I have to do (it's amazing how that stuff that's almost invisible before paint shows up so well with a coat on)....

While I wouldn't do a topcoat with this humidity, do you think primer would be OK? The package just says that humidity may increase drying time, and I'm OK with waiting a bit longer if it means painting sooner....
I would follow the environmental thresholds specified by the manufacturer. I have a digital thermometer and humidity gauge in my painting room just for this. If it is out of spec then I don't paint.

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I reread the instructions, found the range. Under 85% RH should be achievable.
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I have sprayed primer on very humid days with no problems.

As long as the temperature is at least 7-10 degrees above the dew point when painting.
BELOW that is where the trouble starts!

Painting in direct sun helps too.

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