Paint curing questions

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Lugnut56

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How long after priming and/or painting with spray paint does the paint need to "cure" before being exposed to cold temps? The issue is my wife has a nose like a bloodhound (sensitivity wise, not appearance wise:wink:), and has informed me there will no more paint smells coming in from the garage. After 39+ years of marriage, I totally agreed. What I would like to do is set up a small paint booth (cardboard box and large trash bag) heated with a small space heater in a small shed in the backyard, but I don't want to leave the space heater on too long unattended. I would like to do my priming/painting, leaving the heat on for a couple hours, but then let the rocket set for a couple days before bringing back inside the house. Will exposure to cold temps hurt the primer/paint if kept heated for a couple hours after painting? If not, how cold is too cold? I am using Krylon primer and paints 99% of the time. The night time temps have been avg. around 30 degrees F.
 
The closest I have come to your situation is what I just did last week. I sprayed several coats of Rusto 2X on a 3 foot tall, 3 inch diameter rocket at a club meeting using the paint hood. I let the rocket dry for about an hour before taking it out to my car. A couple of spots felt tacky, but not to bad. It was below freezing that night and my car had sat outside for 2.5 hours, so it was cold in the car. I put the rocket in the backseat and drove home. I took the rocket stuff out of my car later the next day or maybe the day after. It seemed fine and I didn't notice any smell from the paint, but I didn't do a sniff test.
 
With catalyzed finishes, temperature during application, and during the cure is very important, some requiring high cure temps / IR heat lamps.

With almost all rattle cans, temperature is not as big of an issue. It will eventually cure. Once it 'flashes off' and most of the solvent has evaporated, most of the danger from flying debris has passed. It still needs to be cured hard before it is safe for handling.

For your shed, one of those oil filled radiator type space heaters is safest, and painting when the temps are warmer (in the Winter) is better. You could make a tent above one of the 'oil radiator' type heaters, and get a very good cure in a few days. It would probably be safe to handle much sooner than that, for most rattle can finishes.
 
Thanks for all the suggestions and advice guys. I will cobble together some form of tent/booth tomorrow and set up a heater.
 
I have a box from a dryer/washing machine that I use. Its easier for me to control the temp INSIDE the box than the whole garage. Dont worry, the heat lamps will not catch the cardboard on fire, However, keep an eye on it when your painting. There is a small 6x6 square in bottom. I lay the box on its side, and punched a hole in the top that I have a screw and washer through. I drilled out a dowel and I can hand tight the screw into the dowel with rocket on it. It also allows me to rotate the rocket as Im painting. The dowel also helps me from touching the wet paint that usually happens. I have a heat lamp setup I use to get the heat inside the box at a much much warmer temp than outside air.. I move lamp away.. spray.. Move lamp back and rotate rocket so that the paint cures evenly. its not perfect but the results are more than satisfactory for the rockets im painting. By increasing the temp the paint cures alot quicker, like ALOT quicker...

*NOTE* do not attempt to hook up shop vac to expel vapors from box.. bad things can happen... I would recommend a typical "low speed fan" to move the vapors if that's an issue.

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With catalyzed finishes, temperature during application, and during the cure is very important, some requiring high cure temps / IR heat lamps.

With almost all rattle cans, temperature is not as big of an issue. It will eventually cure. Once it 'flashes off' and most of the solvent has evaporated, most of the danger from flying debris has passed. It still needs to be cured hard before it is safe for handling.

For your shed, one of those oil filled radiator type space heaters is safest, and painting when the temps are warmer (in the Winter) is better. You could make a tent above one of the 'oil radiator' type heaters, and get a very good cure in a few days. It would probably be safe to handle much sooner than that, for most rattle can finishes.

In my experience, after 30 minutes or so all colder temperatures seem to do is slow down the cure time. I have buzz bombed quite a few items in all kinds of weather and enamel paint eventually cures no matter the temperature.

I have a box from a dryer/washing machine that I use. Its easier for me to control the temp INSIDE the box than the whole garage. Dont worry, the heat lamps will not catch the cardboard on fire, However, keep an eye on it when your painting. There is a small 6x6 square in bottom. I lay the box on its side, and punched a hole in the top that I have a screw and washer through. I drilled out a dowel and I can hand tight the screw into the dowel with rocket on it. It also allows me to rotate the rocket as Im painting. The dowel also helps me from touching the wet paint that usually happens. I have a heat lamp setup I use to get the heat inside the box at a much much warmer temp than outside air.. I move lamp away.. spray.. Move lamp back and rotate rocket so that the paint cures evenly. its not perfect but the results are more than satisfactory for the rockets im painting. By increasing the temp the paint cures alot quicker, like ALOT quicker...

*NOTE* do not attempt to hook up shop vac to expel vapors from box.. bad things can happen... I would recommend a typical "low speed fan" to move the vapors if that's an issue.

I used to have a make shift curing oven in my scale modeling days that was nothing more than an old appliance box (from a dishwasher I think) with a 50w incandescent bulb in the bottom. One side of the box was cut on three sides to make a door. If I kept my paint project near the top, it would cure quite nicely.
 
Thanks again for all the suggestions. I ended up using 1/2" PVC pipe to build a frame with a piece of 1/2" plywood as a platform to support the small electric heater and the rockets. I then used large plastic yard bags attached on 3 sides and over the heater "duct" using zipties and duct tape. On the 4th side, the bag is attached only at the top so there is access to the booth. A section of dowel is attached to the bottom of this flap to hold it closed. I use a laser thermometer to check the temp of the rockets before painting. I've used it the last couple days on 3 different projects for priming, and it works great. I have approximately $25 into this. The PVC pieces are not glued together, just a friction fit so I can change the height of the covered booth section easily if needed (or break it down for storage). (Sorry, but was unable to get the pictures to rotate)




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