Compressed air can - How to make larger one, refillable?

Hello!

You know those compressed air can for cleaning dust form electronics and computers. They are working well, but if you use them a lot they become pretty expensive. For heavy user's alternative is to use compressor. They are not so expensive any more, but they are loud, heavy, large and not so practical to carry with you…

So, after take in consideration that written above great thing would be to make reusable, larger, compressed air can. Something simple to use, some on/off leverage and small nozzle, and also refillable - fill it with that compressor which is heavy and loud. Some manometer would be nice, just to know how much air is inside. That "can" should be larger than

Do you have any idea how to make it? Please share details, ideas, plans, other help…
Thank you in advance! Best to all!

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davor07 (author) 5 years ago
What do you think about something like this

http://www.diylife.com/2008/01/14/mini-air-tank/

Thx for comments!
Thrasym davor075 years ago
Should work a treat.
this is a strange math.
A gas is cooled and compressed till its a liquid.
Stored in an enclosed canister.
At room temperature some of the liquid will boil off till the pressure above to liquid is high enough stops the boil.
Releasing the gas allows more of the liquid to boil replacing the gas that escaped.
This is how a steam boiler works, the temperature determines the amount of gas pressure the vent of the pressure will remain constant as long as a: liquid remains b: temperature remains the same.
ie my cans of "dust off" spray good till the can gets cold then no pressure.
I like this a bunch
http://www.ryobitools.com/catalog/18v_oneplus/specialty_tools/P3200
it works great no cord
Thrasym5 years ago
Uh...you can't just jerry rig a compressed air canister. The pressures involved are enormous, as in, if a part fails it will destroy your house and your body will never be found. That's only a slight exaggeration. You can get a butane or propane can from the hardware shop in various sizes, with all sorts of attachments you could modify for air use.

But, there are lots of little vacuum and fan/blower kits, made specifically for what you want to do, clean keyboards and motherboards and such. They're usually in the $10 to $20 range and either plug in or take a couple AA batteries. Found in automotive, home, gadget and electronic stores. Cheap and easy...
davor07 (author)  Thrasym5 years ago
Thank you for heads-up. But I don't understand how could it be so dangerous? If you compare it with small cans, I need only bigger volume, not higher pressure? Please explain a little bit.

I thought that fire extinguishers "bottle" could be a good start… Or small propane can, as you recommended. How could it be so dangerous? If you use it with gas, with "air" shouldn't it be less dangerous?

About little vacuums or blowers, they don't have enough power to do the job. I tried it few but I was always disappointed... Do you have good experience?
Thrasym davor075 years ago
*fist*...half the time I hit post it doesn't show up on this site...grrr...I'll retype!

Ok, the math is like this. Lets say you do 50 PSI in a 5" x 12" canister, that is 5x12x3.14159=188.4954 cubic inches...188.4954x50=9424.77 pounds of force contained. NINE THOUSAND POUNDS...that's the weight of 53 fully grown men.

The type of gas doesn't matter, the math is the same, air isn't combustible though, so it's safer than some gases in that way. If you use a canister designed to hold pressurized gas, it should be safe enough, worst case you modify something that springs a leak and you get a blast of air that ruins your hair do and knocks over the canister.

The little gadgets haven't worked for me either. But I've only gotten the junkers, once spent $6 at the sale table after fathers day or xmas, I forget which and got another at the dollar store. Figured there'd be better results if I spent more for a better quality kit, but perhaps not if you had similar results.
davor07 (author)  Thrasym5 years ago
Hello!
Thank you! What is the math with that "small" compressed air cans from stores? What is their pound of force inside? Are they presurised the same as this big one I would like to built?

photos of small ones:
http://tinyurl.com/compressedaircan


If I could make big bottle with much more of the compressed air inside, it doesn't have to be more pressurised than "small air can".

Thank you for all of your effort!

Thrasym davor075 years ago
I think my math is off, I'm certain I'm missing something but can't remember what...hopefully someone will correct me. But the general idea is that with every square inch or cubic inch you add, you increase the pounds of force the canister has to withstand by the pressure the gas is at. So at 50 PSI it would add 50 pounds of force each inch.

I don't know what pressure those little cans a propane torch canister is pressurized at, but 50 PSI is fairly low so I used that as an example.

Again, it isn't that it is "more pressurized"...it is that even at the same pressure, 50 PSI, the "force" contained (the "potential for damage"), becomes far greater as the size increases.

If you make sure to follow the info on a refillable canister, not going over the recommended PSI, it's nothing to worry about. I was only warning against making your own canister as there's a good chance that could explode in your face as you're filling it up.
lemonie5 years ago
It isn't compressed air.
It's other compressed-gas.

L
davor07 (author)  lemonie5 years ago
They advertise it: compressed air can...
What kind of a gas is in it?