What is the "right" humidity

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Dec 5, 2003
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for painting? I've been watching the humidity lately and it's been in the 80-100% range. Does anyone keep track of the humidity before they paint? What are the results?
I dont realy bother with the Humidity over here . Where I paint is vented , and I leave a small heat blower on 24/7 whilst it cures.
Maybe that's why my paint jobs are so cra**y :eek: :rolleyes:
I have not found a way to get decent paint jobs above 60% or so humidity. The high gloss paints get a dull "blush" on them.
The humidity can be rough (read: unbelievably high) here in Central Florida & I know that places in the SE US, like Alabama, are pretty much in the same boat.

My advice is to wait till the afternoon of a day when it has not rained earlier in the day. Mornings are too muggy (or foggy) meaning the humidity is high & rain definitely rules out any painting... Mid to late afternoon--but well before sunset--has been the best time for me because the humidity still isn't low but is low enough for me to get some very good paint jobs. Make sure to paint in a location where you get direct sunlight too. That's about as good as it gets here...

Now as good as it is for the yard to get rain everyday, I haven't been able to paint anythign for weeks because of the daily thunderstorms :(

I've noticed the gloss paints blushing in the FL humidity. Not a big deal for me, since all my new rockets are getting the Future Floor/Rocket Polish treatment, and that IMMEDIATELY gets rid of the blush. Hey! Quick hint for you scale modelers...

Got only glossy paints available? Can't find a flat color? Wait till a humid day - it'll take that shine right out of it. Hit it then with a spray of dullcoat, and it'll be perfect!

I watch the weather channel and only spray finish coats when the humidity outside (where I paint) is less than 70%.

I also equilibrate the spray paint and the model to the outside temperature before I paint.

Bruce S. Levison, NAR #69055 Section #535 Tri City Sky Busters
Originally posted by tmcqueen
for painting? I've been watching the humidity lately and it's been in the 80-100% range. Does anyone keep track of the humidity before they paint? What are the results?

Rustoleum says:
60%: primer, satin finish
50%: metal finish, applicance epoxy, metal flake in gloss, high heat, flat finish and gloss.
Deft spray lacquer sanding sealer says nothing about humidity, but it's based on a great deal of very light aromatic hydrocarbons, and its finish is intended to be sanded anyway.

When it's humid I take mine into the basement after spraying, which may have similar relative humidity, but lower absolute humidity. Seems to help.
Thanks everyone, these are all great suggestions. I've been going off of the %chance of rain in the forcast, and try to paint on days that have a forcast in the 20-40% range, with mixed results. I bought a hygrometer a few days ago and have been keeping track of the humidity outside the house.

The humidity in Central AL just dropped below 60%, so it looks like I'm going to get some painting done this weekend!

I can't win.

I'd built my Vulcanite without a launch lug for launching on a tower. I decided to add one. After that I needed to repaint it. Rather than the same (pretty nice) gloss blue, I decided to go with cobalt metal flake and clear gloss coat.

The temperture got over 80 and the humidity got below 60, so out I went. What could happen? Both dry in like 20 minutes.

An hour later, all dry and ready to bring in, and I discover.....

dandelions. Fuzzies had glommed onto my paint and turned into cobalt blue and clear coat boogers.

I don't HAVE dandelions. I can't see any anywhere.

But, apparently 60% humidity is just fine for Rustoleum metal flake and clear gloss. Except for the boogers, it looks good. I took some pics. I'll post them when they're processed. Boogers and all.