Compressed Air Question

H

hijynx54

Limp Gawd
Joined
Jul 11, 2005
Messages
256
I just borrowed a can of my friends compressed air today, and noticed when I used it, it sometimes release a liquid substance. I have never seen this before, but he said he thinks its the kind "that dissolves dust". What is your all take on that? Reading the can it seems like it is some sort of anti freeze flammable liquid though. It was used on my old computer, but I was doing quick bursts and it got on my vid card, mobo, and a few other parts and dissapated real fast. Do I need to be worried? Should I just not plug it in for a few hours? Or is it nothing to be worried about? Thanks
 
nifty thing... turn the can upside down, it'll freeze anything... just be careful with the skin - tends to sting... lol

the "liquid" shouldnt hurt anything, as ive had it spray out numerous times @ work and home, and no damage done. ^dont quote me on this, im just saying from my POV*
 
optlox said:
nifty thing... turn the can upside down, it'll freeze anything... just be careful with the skin - tends to sting... lol
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so much fun at lan parties...
 
Dont worry about the liquid, it evaporates instantously. Plus I dont think it conducts anyways
 
Yah it appears to have caused no problems, but I cleaned my main comp too, and WOW. I went from a steady 34-37C to a 28-29C. Only is a 6 month old comp, but there was a decent amount of dust build up on the heatsink (xp-90c). Though was a bitch to clean the front 120MM fan (lian li pc65b). Thanks for the help though with the vapor.
 
The liquid's only an issue if dealing with something vulnerable to thermal shock. You shouldn't use compressed air on optics forex.

Edit: the liquid's the gas used as a propellant.
 
The liquid is r134 refrigerant, same stuff used in A/C units now. It's the only thing in a can of compressed air. I'll waste a whole can freezing stuff. You can get frostbite if you get it on you so be careful. It also cause water to condense and freeze on what you spray it on so make sure you've unpluged the computer before you start sprying it everywhere.
 
Canned air products are better called "canned air" rather than compressed air. Compressed air, like what you'd find at an automotive shop, is at a high pressure, around 200 PSI, wheras the liquid in the canned air can is only around 1-5 psi greater than sealevel pressure. It just so happens that the critical pressure for r134a is very near sealevel pressure at room temperature, so in the can it is stored as a saturated liquid, and when the pressure decreases, as it leaves the can, it expands to vapor. That is why when you release a lot of it the can gets very coold, because the heat of vaporization is fairly large and it will pull heat out of the surroundings. When you turn it upside down, it sprays out the saturated liquid, which very quickly boils and turns to vapor.
 
Actually, the stuff in the cans is at over 40 PSI. I've tested it my self for charging up my air cannons. I stuck the straw onto the seal in the CO2 adapter on my small one, and managed to get it up to a little over 40 according to my gauge on it. It probably whould have been higher if it was not leeking slightly around the little tube.

This was Staples branded stuff by the way, and in the winter outside (abour 50f).
 
Quick facts:

*Air pressure at sea level is 14.7 PSI
*Retail "Canned Air" vary between 40 and 70 PSI (whatsisname, 5-7 is WRONG, sorry :( Nailed the heat-transfer and vaporization, though)
*Most "Canned Air" products are R134A** or TG134A, though some variants exist (example, "Dust-Off" brand is 152A, (ethane). Most canned airs with no displacement gas are non-flammable, because R134 is not. Dust-Off, however, is HIGHLY flammable, due to both the liquid, and the propane they use [to make the bottles seem bigger])
*The if a "displacement gas" is used, it is usually butane/propane (hence the FLAMMABLE)

Breathing the gas directly, while making your voice deep, DOES kill cells. Standard Staples/OfficeMax/CircuitCity/BestBuy brands aren't too dangerous, but I can't stress enough how bad the Dust-Off brand is. Nothing against them, but they choose to not only use the not-industry-standard mix, but then use displacement gases to make their 8 and 10-ounce bottles bigger than the competition, which increases danger (and flammability).


**For those wondering, R134A is 1-1-1-2 tetrafluoroethane
 
EventHorizon said:
You can get frostbite if you get it on you so be careful.
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I got bored one time and found that out the hard way. I had a spot on my hand for so long I thought it was going to scar, lol. I'll tell you one thing, if it were 200 PSI, I would know (there WOULD be a scar.)

BTW, what about "CleanSafe" brand (from Walmart)? I bought it hoping that the big can actually held more in it, but, I looked and it says it's 10 oz, so maybe they are just pulling the same trick Dust-Off is. Apparenty they added something they call "bittergent technology" (I think this just means it feels really unpleasant to try to breath it directly, but, I haven't really tested) to keep you from misusing it on purpose.

Oh, yeah, and while the stuff evaporates pretty quickly, I'm thinking that if it can give you serious frostbite, it probably isn't good to spray too much liquid directly on components. I've also been told that if you spray directly onto a motherboard or similarly protected PCB it can take the protective coating off (I don't know if this is supposed to be due to the pressure or the temperature. If temperature, then you're probably ok as long as it's not coming out as liquid and you don't spray the whole bottle in one place, but, I suspect it's due to the pressure that people tell me this.)

Don't forget to tell your friend that he's crazy for thinking that the liquid "dissolves dust." d-:
 
Nazo said:
BTW, what about "CleanSafe" brand (from Walmart)? I bought it hoping that the big can actually held more in it, but, I looked and it says it's 10 oz, so maybe they are just pulling the same trick Dust-Off is. Apparenty they added something they call "bittergent technology" (I think this just means it feels really unpleasant to try to breath it directly, but, I haven't really tested) to keep you from misusing it on purpose.
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Dust-Off has that same "bittergent technology". It just makes your throat sore after you use it, and leaves a bad..."taste" (I was convinced to do the deep-voice trick ONCE with Dust-Off). My throat was sore for longer than half-an-hour, and it toes taste like crap (as it should). And yeah, I've seen some brands at Wal*Mart with the huge bottles, but it's the same 10 oz.

And about the protective coating, it's not pressure or temperature; it's chemical makeup. But almost no canned-airs do that anymore. The problem was with an old (and if I remember correctly: now illegal) mixture. Now all canned-airs have to use "safe" mixtures, like the ones I stated above. The dissolving the coating isn't a problem anymore. (and this "coating" doesn't really do anything anymore :p ).

With the "frostbite" you can get from it, I'm not too sure, but I'm almost positive that it could happen. I've been in the same situation where a coworker (read: jackass) suddenly pinned my hand down and sprayed the back of my hand for about 15-20 seconds. I had a spot that hurt for a long time, and it got darker, then subsequently lighter, over time (like a bruise).
 
my friend used a can upside down on his brother for 20+ seconds. he now has a scar from 2nd degree "burns".
 
Reading through some of these threads it just goes to show that just because a person may be knowledgable about computers or technology, it does not make them smart.
 
agent420 said:
Reading through some of these threads it just goes to show that just because a person may be knowledgable about computers or technology, it does not make them smart.
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Bah, I learned that YEARS ago when I first started driving. Just recently I was given the perfect proof of human stupidity that surpasses anything you can find in any thread. I was driving along on the highway, going about the speed limit (+/- 2 or so,) in the right lane since there was no traffic to speak of, and saw a guy in the median who wanted to pull out. About a half mile behind me was a truck also in the right lane. Well, the guy I guess looks at me and decides I'm going too fast for his tastes (and apparently the completely empty for a mile in both directions left lane doesn't exist all of a sudden) so he decides to wait. He keeps waiting for the apx half minute it takes me to get to him, then, suddenly, just as I get there, he decides he can't take it anymore and pulls out, skipping the left lane to approximately one car length in front of me. This is with me going 70MPH I should add. Somehow I dodged him, though I moved the car so fast it started swerving and I nearly went off the road (didn't have to worry about hitting him since I was past him in less than a second, but, off the road isn't pleasant either for a relatively low to the ground little fwd car.) My point to all this? The natural instinct when you see someone moving towards you at high speed (and this even includes if you're out walking and see someone running towards you at full speed) is to step out of the way. It goes against instincts themselves to do something so massively stupid.

Never again assume humans -- however intelligent they may or may not be -- are incapable of doing things that are so massively stupid it leaves you wondering if an ape wouldn't have done it better.
 
EventHorizon said:
The liquid is r134 refrigerant
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Stuff I get is filled with liquid propane. Smells REALLY bad when you constantly use it. There is also CAUTION FLAMMABLE posted all around the can.

I know commercial companies use liquid nitrogen to clean their PCB's, its nice and dry so they dont have to worry about any condensation issues.
 
DaRkF0g said:
I know commercial companies use liquid nitrogen to clean their PCB's, its nice and dry so they dont have to worry about any condensation issues.
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Semiconductor companies use N2 to clean wafers, but it isn't for the condensation avoidance--it's because N2 reacts with practically nothing. no corrosion, no deposition on wafers, no residue. Oh, and it's not poisonous (unless it displaces all the oxygen, of course).

 
DaRkF0g said:
Stuff I get is filled with liquid propane. Smells REALLY bad when you constantly use it. There is also CAUTION FLAMMABLE posted all around the can.
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Ah. I was talking about most all of the Wal*Mart and Staples brands that are "non flammable." Oh, they're still flammable, but just not as MUCH so :p
 
When I owned snakes I use to "knock out" mice/rats with the stuff before feeding them to the snakes. Put them in a jar, fill with canned air, watch them fall asleep, feed them to the snakes.

May sound mean, but it's really less cruel then slamming them against a wall/floor by their tail like many snake owners do.

BTW this thread went really OT.
 
I use the stuff to freeze off warts and skintags.

just saturate a cuetip and press it onto the skintag and you will hear a burning sound and it will sting a bit, when it starts to do that, you take it off and do it again in about 20 seconds. Within a week or 2, the warts will peel/fall off and the skintags will turn brownish/black then fall off.

you can also do this with small extruding moles (you have to freeze them a bit longer though)
 
That's how the treatments for those work. However, you're pressing something that's a little poisonous into your skin, so you might want to think twice before considering it a long-term solution (short-term is basically ok.)
 
Yep - I used to go to the Doc to get my warts frozen off with Liquid Nitrogen. He had this cool gun with a small tank & a large canister where he stored all the nitrogen. It damned HURT. But as they all said - No damage to your mobo. I've used the stuff. Heard it's bad to breathe in, poisonous? I dunno. Maybe in large amounts. Liquid Nitrogen is your best bet though. Supposedly it's cheap - and if you wanted you could use it to cool your computer and get some sub-zero temperatures :D
 
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