Canned air

You can get around the freezing air can issue by standing it in warm water. it will also restore the air pressure.

GMorrison

contents of the can are anything but "air'. Fluorocarbons, which you don't want to inhale

don't you mean hydrocarbons?

what was this thread about....

Hello there !

   Now that you have straightened us out I will say this .The pressure is high , the can gets cold and there ain't enough in there to do a good job . Now , I thought it would be good for cleaning old models and Model Train parts . Not the Case .

 The beginning pressure was so high it blew the handrails right off the boxcar to heavens knows where . Then when I really needed it , it had lost enough umph as to be useless . Guess I'll just use my compressor with an adjustable air nozzle ! . Besides the compressor has paid for itself twice over . And canned air , though cheap , isn't so on a big project !

Ah!  I find the canned air pretty expensive for that.  It was mostly used for photographers to blow dust off negatives before printing.  But the alternate was a little bulb sprayer.

Personally, I have used airbrush for cleaning models before painting, or after they have sat on shelves for awhile to clean dust off. I use a siphon feed brush so I just take the paint bottle off (which is left with thinner), press trigger for a few seconds to make sure thinner used up/cleared from brush passages, and then dust model with it- works great!

Yeah, I was talking about hot glue. The thread has kinda drifted to using canned air for painting.

And yes, I'm referring to the canned air used to blow out dirt, dust and debris. Not the canned air used for air brushing.

Way to much science in this thread for me :) mike

Be aware too that the contents of the can are anything but "air'. Fluorocarbons, which you don't want to inhale, and often bittering additives so you can't deliberately inhale it.

Yes, bad for the greenhouse layer as well, although fairly insignificant problem in this case.

But I think the OP was referring to the use of the gas to harden hot glue. I don't use hot glue, so have no experience to offer.

qmiester

Don,

It's called "Latent Heat of Vaporization" which basically means that if you compress a gas, heat is released and if you decompress the compressed gas, cold is released.  (It's one of those strange things that has stuck in my head from when I went to A&P school 45 or so years ago)

I thought latent heat of vaporization is the cooling of a liquid when it undergoes a phase transition from a liquid to a gas.  I think the cooling with pressure reduction is called Joule-Thompson cooling, and is a result of the PV=nRT thing.

No. Canned air for airbrushing does that. It isn't that it releases cold as the gas expands in the can. It's that it absorbs heat as it expands. Anyone who uses canned air to paint models on a regular basis is better off buying an air compressor. It will pay for itself in a matter of months. I know. I started out with canned air.

I'm assuming by canned air you're referring to the type for cleaning keyboards and computers and not the one that you can attach airbrushes to?

Don,

It's called "Latent Heat of Vaporization" which basically means that if you compress a gas, heat is released and if you decompress the compressed gas, cold is released.  (It's one of those strange things that has stuck in my head from when I went to A&P school 45 or so years ago)

I use it to spray thinned washes to replicate fluid leaks

Also, as you use it in an airbrush, the can continues to cool, and will reach a point where it doesn't Propel any more.  The constant change in pressure does not make for good airbrushing.  So don't rely on that stuff for airbrushing- get a compressor as soon as you can.

Before I bought my first compressor I tried sitting the can in a pan of water.  It did slow down the pressure drop slightly, but the pressure finally really dropped. I wondered if shaking the can would help.  When I picked up the can to shake it, the pan came up too!  Turns out, it had frozen all the water in the pan- that stuff REALLY gets cold.

Sounds good.

Canned air is cold an that makes it crappy for acrylics in the airbrush.