Refillable Air Can Life Hack

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Introduction: Refillable Air Can Life Hack

In this life hack video, I am going to show you how you can refill your air duster can with a bicycle pump.

Step 1: Items Needed

All you need is an empty air can, some liquid metal epoxy and a tank valve similar to what is used on a bicycle tire. You will also need a drill and 3/8" bit.

Step 2: Make Sure Can Is 100% Empty

Start off by making sure there is no air left in the can. We really don’t want to start drilling the can while its pressurized.

Step 3: Use 3/8

Next, choose a drill bit that matches the width of the air valve. Mine happened to need a 3/8” drill bit.

Step 4: Thread Valve Into Hole

I decided to install the valve further down the can to keep it out of the way. Once the hole is made, you should be able to thread the valve right into the hole.

Step 5: Mix Liquid Metal Epoxy

Now its time to seal it up with the liquid metal epoxy. I cut the end from a cue tip to mix the 2-part solution together.

The cue tip also made it real easy to apply the epoxy directly to he valve. The instructions say it cures in 8 minuets I let it cure for a few hours. This stuff is rated for 3500 PSI so its complete overkill but its better to be safe than sorry.

Step 6: Connect Air Pump

Go ahead and attach a bicycle pump to the valve and let’s add some air!

The recommended pressure rating on this can was 70-90 PSI so lets keep this extra safe and only fill it up to 60.

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72 Comments

good idea, but i would drill the hole in the bottom, where the material is the thickest, and solder it and no glue it

I do not like this idea....looks potentially dangerous to me...

Very clever!

Have you used the refillable can for a substantial amount of time? I'm curious if you have done enough refills to speak to its long term durability. (I'd be slightly concerned about it rupturing and causing harm, but this looks like a potentially very useful idea!)

3 replies

Thanks!

I just finished the build so I don't have many miles on it yet.

The epoxy is VERY strong so I don't expect it will fail.

With that said, only time will tell. :)

see my comment about epoxy and what you call strong.. in what sense ?

I myself would use a sealant designed to seal a threaded pipe, such as natural gas lines or such. and try to solder the valve into place.

I hope that everybody understands that 'canned air' is not air, but a liquid hydrocarbon under pressure that becomes gaseous when released to normal atmospheric pressure. A popular material used in 'duster cans' is 1,1-Difluoroethane, with the chemical formula C2H4F2. , Also known as Refrigerant R-152a. R-152a has a vapor pressure of 63 psi at 70F. So the pressure in those duster cans is normally around 63 psi. A can of R-152a will last eons longer than a can of true compressed air because a can full of liquid R152a expands a vast amount when it changes to a gas.

I would be very hesitant to compromise the integrity of the wall of a pressure vessel, which is what you are doing by adding a tire valve to the side of a can.

I would not think that this approach would work well for trying to make spray cans, since they also use hydrocarbons under pressure which expand with the paint (or other liquid) as they exit the can -- Air just does not perform the same.

9 replies

I haven't seen and difloroethane duster cans (i am sure they exist as i have seen that as a propellant for air horns or possibly trifluroethane I can't remember) but I have seen butane duster cans

as can be seen in the images attached these air cans contain the Diflouroethane spoken of. I've never seen one using butane. although butane and propane are both used as propellants, but the cans are always marked Flammable.

Air Can.jpg

You sure about a butane duster can? If any little spark it would blow up!

That is what they switched to after the CFC ban. Then they switched to HFC as soon as they became available and reasonably priced. You can buy a tank of R134a and refill all your air dusters with it through the trigger without ever puncturing the can.

user

Most are difluoroethane or tetrafluoroethane. (HFC152a, HFC134a respectively)

Mostly 152a now, because 134a is quite a bad greenhouse gas.

152a breaks down in a few years, instead of 100, so while it's still bad, it's much less bad.

I have actually never seen butane sold as duster.

this guy has a clue too ! not like some rube that plumbs his shop air with pvc.. shrapnel waiting to happen.. if metal piping gets a leak, its a relative pin hole and only hisses.

PLUS ONE ! Putting compressed air in such a container is a fraction of the capacity of the gaseous stuff that commercial canned air can generate. It's no so much about the pressure in the can as the "magic way that the contents can generate a longer flow of air, due to the conversion from gaseous to whatever upon being released (trigger pulled).. trying to put the idea in layman's terms...

user

You are bang on the money there (unlike the can above which may go bang in your face :( ). The MSDS for this product says : "1,1-Difluoroethane/75-37-6".

user

You can see it on the photos in the instructable too. Most of it is visible in step 3

I bought one of those refillable air blowers - it never lasted very long and the recharge cartridges were expensive. I should make an instructable for making your own sparkling water (saving money and the environment). hmmmm,

You'll have less than 3 seconds of air ! RS sold such items 25 years ago, they never worked !

2 replies

If the can is safe to 90psi and you fill it to 90psi then technically its full again and should last almost if not as long as the original surely?

user

No. Because the original can was compressed to 90 psi gas pressure over a bunch of liquid. The liquid turns to gas maintaining the pressure at 90 psi (if that) all the way to the end, when it runs down in very short order.

You refilling it with 90 psi gas ONLY will give you 90 psi and falling immediately. The "RS item" named above is probably similar to the Jennican I mentioned higher up. They do work. They provide pressure for a very limited time -- because it is ONLY gas. Not Liquid. If you try and pressurise air into a liquid to achieve this, you won't manage it in a flimsy little aerosol can. That's why aerosol cans don't used compressed AIR -- it's too hard to compress to a liquid. All these CFCs and HFCs, butane, propane are relatively easy to convert to liquid at low pressures.