Best temperature to spray paint model rockets

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Xan2482

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Hello,
I was wondering what is the best temperature to spray paint your model rockets? When I use Testors spray paint the instructions tell me the best temperature to spray paint is 70 degrees. Your advice is greatly appreciated in this matter.

Xan
 
I expect that the paint manufacturer has a good handle on recommending paint conditions. I've found that 70 is a good target, though this time of year I can't keep my painting area that warm. Its probably closer to 60, colder near the floor. What I can say is that spray paint starts to spatter around 50 degrees, and won't lay down well. It helps to keep the paint itself warm. I bring the paint can back into the house with me between coats to keep it at room temp. I've also set it on heat ducts to warm it up. In fact, I've often brought the model into the house once the paint is tacky and stood it over the heat duct to dry. You just have to be wary of dust/debris coming out of the ductwork...
 
This is very paint specific. You need to use the manufacturer. If you can't easily find it 70-80F is usually OK. Any colder the viscosity is too high for the paint to level and hotter the paint may dry enroute to the surface.
 
Like above, consult the instructions. Be aware that in addition to the temperature, the humidity also matters.

Most paints these days are enamel, and relatively slow drying, and thus less affected by humidity, but if you have a lacquer, it will be prone to milking/blushing in humidity over 50-60% depending on the temp.

I've sprayed lacquers just fined down to 15 F. And at up to 90 F in low humidity. Enamels almost always gave me lackluster results, and I switched to airbrush acrylic paints...
 
Like above, consult the instructions. Be aware that in addition to the temperature, the humidity also matters.

Most paints these days are enamel, and relatively slow drying, and thus less affected by humidity, but if you have a lacquer, it will be prone to milking/blushing in humidity over 50-60% depending on the temp.

I've sprayed lacquers just fined down to 15 F. And at up to 90 F in low humidity. Enamels almost always gave me lackluster results, and I switched to airbrush acrylic paints...

What is this 'humidity' that you speak of?
 
What is this 'humidity' that you speak of?

Something those in AZ don't have to worry about unless its actually raining.:D

The paint manufacturers recommendations should always be followed, however if you can only get the temp to 50F try a test piece first, I had some enamel a few years ago that "alligatored" on me at 50F, but at 55F worked beautifully, the manufacturer recommeded 60F. Humidity can be a factor once again a test piece first.
 
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ok. can it be too hot to paint? The only space I have for painting is a patio here. daytime temps are 100 plus, and even early morning it'll be at least 90
 
ok. can it be too hot to paint? The only space I have for painting is a patio here. daytime temps are 100 plus, and even early morning it'll be at least 90
The Rusto cans say between 50 and 90, so you're definitely pushing it. If you can keep it to 90 or so you should be OK. I wouldn't personally be inclined to paint when it's 100.
 
ok. can it be too hot to paint? The only space I have for painting is a patio here. daytime temps are 100 plus, and even early morning it'll be at least 90
Yes it can be too hot to paint. Paints are dependent on both temp and humidity. You can have the prefect temp but too high humidity, and with some paints, too low. If it is too hot, especially with low humidity, the paint actually starts to dry in the air and you get a powdery finish. If it is too humid moisture can condense into the paint or on it and you get a milky surface that may not cure properly. Different paints have different tolerances for heat and humidity. One thing I've learned to look at is the dew point, In my experience with the paint I use, the dew point should be at most in the low 60's. And temps at 90 or below, but even that is pushing it with some paints.

If in doubt, test on a scrap piece of PVC tubing or something similar before committing to painting your rocket.


Tony
 
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