Im using my stand up Compressor for air and I was wondering if painting inside at room temp with air from an air compressor in the garage, that is at freezing or lower, is asking for trouble, especially with acrylic paints. I have a badger moisture trap on my hose.
Thx in advance,
Mog
I don’t think it will present any troubles since the air is warmer where the painting is done. Give it a try and see how it does.
Mike
When you compress the air it’ll heat up anyway more than you would think. That is why they put Intercoolers on Turbocharged engines…I wouldn’t worry about the temperature difference. I compress air into a second tank and take it inside to paint. As long as you have a moisture trap, you shouldn’t have to worry about it.
Dan
The compressor does heat the air a little, but in a very cold atmosphere like the one described in his garage, I don’t think the air is going to get very warm at all unless you spray for extended periods with no air tank. When I empty the small air tank on my Million-Air compressor I sometimes get little pieces of ice that come out of the draincock, so it obviously isn’t very warm in that tank. [;)]
Mike
Actually the ice is from the escaping air. Air under pressure leaving a nozzle gets colder for some reason (I can’t remember the name, something like Aerosol effect). Colder air also typically has a higher amount of water in it, which is why we need moisture traps on our airbrushes even in relatively dry areas. Another way to think of it, is a diesel engine–the fuel ignites solely because the air it is trapped in is compressed 25:1. It can get pretty hot. Granted, I don’t think our air compressors get nearly that hot, but there is a marked increase in temperature.
He’d probably have more trouble with just ambient air giving him fits with the paints–I know I’ve had problems painting something when there is a large difference between the painted objects temperature and the temperature of the paint.
(BTW–I might have a hard time explaining myself in words–this is not meant to be a flame or anything like that. I could be completely wrong here.)
Dan
Cold air has less water content than air at room temperature.
I can’t recite all the thermodynamics off the top of my head, but humidity is a function of temperature; air at higher temperatures is able to hold more water vapor (That’s why you don’t get any muggy winter days)
As a practical example, have you ever noticed that the air in your house is “drier” in the winter? This is because cold air (with lower water content) enters the house, and heats up. It is left with the same amount of water as when it was colder, so it’s less saturated than other times of the year. Hence, it feels “drier.”
As to the accumulation of ice crystals, it basically has to do with the sudden expansion of the gas. Temperature is basically a measure of the amount of energy in the system. When the gas is in the cylinder, the energy is contained to a specific volume. When the gas is released from the cylinder, we have the same amount of energy, but expanded over a larger volume, so it is colder.
Cool! [8D]
I love a physics lesson. [;)]
Mike
Now I remember. Boyle’s law states that as pressure or volume increase, so does temperature. It’s something like (pressure*volume)/Temperature=some constant. So as pressure increases, temperature has to rise to have the right side stay the same constant.
I had it backwards on the humidity issue. It’s been a while since I had physics and chemistry (had to find my old text for Boyle’s law)
Dan
Mogwa, If I understand you right you are tapping the compressor from outside in the Garage and routing it inside the house?? If so then if you have enough airline run through the house to your hobby area than it is probably being heated by the house warmth as it passes through the house. If so, should not be a problem.
I would keep the compressor cold, simply because I like it that way
and my compressor has a tank and it’s always cold.
remember to drain your tank after every use, of water.