While not very technical, [3eff_Jeff] posted an interesting modification to an empty air canister that makes it refillable. He was tired of drilling holes in the ozone, so he carefully drilled a hole into the top of the can instead. In the name of caution, he made sure the can was completely empty first by tying the trigger down with a rubber band. After waiting a while he carefully drilled the hole using an oil lubricant, and then epoxied in a Schrader valve from a leftover bike tire tube.
Due to compression of the air as it is pumped into the can, it becomes quite warm. He found that if the can is allowed to cool to room temperature, the air would become very cold once leaving the canister, which would cause condensation problems. So he uses it right after filling, and then empties it out when not in use.
We do not recommend anyone trying this, but it is a unique way to make a commonly used disposable resource in the computer field reusable. If we can use something more than once, we’re definitely for it. That’s why we support recycling components that would otherwise make their way to the landfill.
Interestingly enough, there was a commercial product like this sold through Office Depot about 10 years ago. It was called EnviroDust or EnviroDuster. It was sold by Fellowes I believe. I’ve often thought of doing this hack myself but always wussed out around the safety issues.
I tried this trick .. unfortunately, the results were not practical. Even at 60 psi, I could get no more than 3 uses @ 1 second each. The first press gave good pressure, the second press half the pressure of the first and the third time I used it, I could barely feel the air. The commercial cans (I think) have a liquid gas that converts to air and hence maintains a constant pressure through out its life.
Hmmm….Why not just use the bike pump to blast the air away in the same way that photographers use a blow brush?
Canned air does not contain any chlorine based CFC’s any more, and do not harm ozone.
You can purchase premade refillable canned air which are cheap, and made for the job with a thicker walled can.
I’ve owned one, the problem is that because these refillable cans do not contain a liquid that transitions to a gas, but instead only compresses the gas they have a very short usable time before they need to be refilled. Less than 10 seconds of use.
when I tried this, it seemed like regular air didn’t compress enough in that small container to be of much use. a 1 gallon tank isn’t as portable but makes more sense, for me at least.
Yeah, sticking high pressure into a can like that one using a epoxied tire valve isn’t your everyday thing.
Interesting nonetheless.
Cool, but they make commercial versions of these which are a lot safer.
Seriously- get a 1 (or preferably 3) gallon air tank, fill it to 120PSI and add on a coiled air hose and blow nozzle. More pressure, more volume, and a lot longer duration. It helps to have a big compressor.
Ive found using an airbrush connected to an air compressor does a pretty decent job, but great idea for anyone who can’t go that route.
This is like the neverending duster hack from back in 06. I’m glad you posted this though, the links to the old one are deceased.
Did the same thing with an empty water jug and some hose.
JB Weld and RTV work.
The jugs held 40-45 PSI before the caps blew.
well for some extra compression points you can always try to cool the can in a freezer before charging and when it hits tops freeze it again then charge it some more. MOAR POWER BLOWS!
Oh, I almost forgot. I bought this thing last time the refillable can hack was run. It’s a bit hard to clean (I use it for paint) but it works with most specialized spraypaint tips, especially the ones that work with Belton, Krylon, Rustoleum, Wal-Mart and Montana cans. Not the wide ones though, you sometimes have to clip the skirt.
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=1102
Not really a good idea, and possibly fatal… those cans aren’t suitable for high pressure air as generated by a compressor, they’re only used for the low pressure generated by the liquid gas inside that is not in the least bit similar in composition to normal air.
To store actual compressed air, you need a container made of steel or aluminium, like the pressure tanks used for scuba diving or for competition air rifles.
If you put too much pressure into such a thin-walled can, it will explode…
The easiest way to make sure the can is empty is to try to dent it with your thumb. If you can dent it, there isn’t much, if any, pressure above atmo in there.
Just don’t dent it too much, you don’t want to weaken it.
This does seem too dangerous though. Seems like a manual bike pump with a needle valve (the kind for basketballs, etc) would blow stuff off pretty well if you’re worried about the environment.
-Taylor
Juergen hit it spot on. the commercial version doesn’t even bother trying to hold highly pressurized gas, it’s in a much safer liquid state.
for a home remedy you might as well fill up a heavy-duty balloon or a chunk of tubing from a bike tire. it would probably work better, too.
I thought one of the features of canned air is the gasses used does not produce static electricity harmful to sensitive electronics. Doesn’t refilling with regular air increase ESD risk?
A friend of mine did this with an empty deoderant can, but he dribbled petrol into it before adding the compressed air. Ah, the things we did with petrol and compressed air…
I wonder what (if anything) you could do about the condensation problem- drying the air you fill it with would probably help but you can’t stop the things you are cooling from having their own condensation.
Oh look. A post thats actually a hack. Good one!
I’ve done this some time ago, but I didn’t drill a hole.
A made a small contruction to refill it through its normal valve. I measured the pressure of a full can to be on the safe side (it was about 5bar).
The problem is that the if water gets inside the can because of air moisture or because you just put water into it (like I did), it starts to rust (very fast!) and if you keep it long anough, it may explode.
So this may be a very dangerous experiment.
You can read my results on
http://wiesi.dyndns.org/diy/spraycan/index.html
if you like.
I’ve thought about doing a similar “hack” as described by blizzarddemon – Just use a Paasche Model DB-32 Tire Chuck with an airbrush connected to a bike tire pumped to 100+ psi (standard road tires can do at least 100 psi) – quick, easy and transportable.
how about old fire extinguisher a bit of water and dry ice? we know that would explode a coke bottle, but can we use it as a duster? who will be brave enough to try?
air compressors are notorious for producing air rich with moisture. do you want to blow that onto electronics? I do like the idea. I don’t know why those air cans cost so much.
Gio
I have thought about this also. I have thought about trying to fit hardware on one of those disposable helium tanks.
I think the best cheap solution is to salvage a junk vacuum cleaner and set it up as a blower. I have seen this done to inflate balloons quickly. Since there is no tank involved, the condensation issue is no greater than the humidity in the air that day. I am just waiting until I see one on the curb on trash day… (No wonder my wife gets pissed!)
I have also used my 1 gallon shop vac by putting the hose on the exhaust side and holding my thumb over the nozzle like it was a garden hose. That PC, (a relative’s,) was almost solid with dust. Its a good thing I did that outside, it looked like a smoke bomb! LOL!
As for the tank getting hot during filling, I used to ride on a volunteer ambulance corp. The Hospital tank service back then would fill tanks very slowly to prevent the heat buildup. An ex-serviceman told me the military submerses O2 tanks in cold water while filling to dissipate the heat so they could fill them faster. (That guy was strange, so take it for what it is worth.)
Wow. 18 comments and not a single pedantic geek has called the post out on the erroneous ozone comment.
Tetrafluoroethane (the propellant in canned air) is a hydrofluorocarbon. Hydrofluorocarbons, unlike chlorofluorocarbons, don’t harm the ozone layer.
CAUTION!!! First off, don’t inflate this thing past 70 PSI, and even then, 70 PSI may be very unsafe. The vapor pressure for Difluoroethane (r152a) is 5.1 bar @ 20 degree C. I would be very concerned that if you were to inflate that thin canister to 125 PSI (like most air compressors are capable of), it could explode in your hand — especially if you are holding it, since the warmth of your hand will cause the gas inside to heat and increase in pressure. I can’t tell you exactly what pressure is present in the can during normal operation, but I can tell you that the can is thin. :-)
Also, normal air contains moisture, whereas the R152a that this thing ships with probably has no moisture content. If the can is made out of a metal that can oxidize, it may fatigue and fail unexpectedly at much lower pressures…
Just be careful out there, ‘kay?
What hack? drilling a hole in a thin can?….things must be slow today. AND…..this is incredibly dangerous…nice sharp bits of shrapnel after the can bursts due to stress risers originating at the drill site. Also, kudos to the folks who have brought up the issue of moisture rich air.
someone makes a ‘canned air’ duster that uses small replacement co2 cylinders, like you use for air-powered bb guns.
why not mod one of those to use the extra-large tanks that expensive paintball guns use?
i like [mikelinpa]’s idea of using a vacuum, too… and points to [3eff_Jeff] for bravery.
Mikelinpa
“ex-serviceman told me the military submerses O2 tanks in cold water while filling to dissipate the heat so they could fill them faster. (That guy was strange, so take it for what it is worth.)”
This is quite true, Go as someone at a scuba shop, They usually put your divetanks in a water bath also!
actually, a blowing adapter for a standard co2 paintball gun is very easy, just get a broken one and use the fittings of of it, all of them have a little tab like thing in the middle that is used to push the needle in the middle of the fitting on the tank in, so all you have to do is twist the fitting off the broken gun onto the tank and it will blow co2 till you loosen the fitting or it runs out. (if i remember right, some places will fill the co2 tanks with other gases so your gun doesn’t turn to solid ice and kill your o-rings when using automatic mode.) i’ve used this method before and it works well, and you can use it to get your overheating pc back under control long enough to shut it down and let it cool off.
Late to the post, but…
When they fill scuba tanks, they have to use dehydrated air, otherwise the hose can freeze shut and, well, no air at the wrong time. If it doesn’t freeze shut, you will still probably coat everything you spray with fine, temporary ‘snow’.