Picture of Propane Tank into Air Tank, The EASY way
I really like turning propane tanks into air tank, they last a long time as an air tank and the standard grill size holds enough air to fill 2 flat tires to 35 PSI on my car. The only problem is that I REALLY dislike removing the valve from the tank, sometimes I would even ruin the valve and not have a tank that is usable at all. On one city clean up day, I managed to get about 4 of these tanks, one was half full or propane yet and was still on the grill, I couldn't remove the regulator from the tank so I just cut the hose and went home with my new stash.

Once I remove the regulator at home, I inspected it a bit more and came up with a new way to get an air tank.

I know there are plenty of Instructables on this topic, but I have never seen it done this way before. There where tons of results that came up on "" Propane air tank" so I may have missed one.

Best of all, you only need one (1) adapter for an unlimited number of tanks.
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Step 1: Remove tank adapter

Picture of Remove tank adapter
Just remove the brass piece that screws into the tank from the regulator, this is easily done by clamping the regulator into a vise and using as crescent wrench to remove it, it is just standard threads which play a BIG role here.

Once it is off, you will either have a tiny, small, medium, or large hole in the end. If you have a medium to large hold, skip the next step.

In my case I had a Tiny hole, not much air will pass through that.

i have one i want to cut in half so i can sell it for scrap- it smells like the additive they put in propane but ive had it full of water- is there any propane in there, or is it just stinky? ive already got 3 air tanks

It smells from the ethyl mercaptan residue they add to the propane to make it smell bad. The ethyl mercaptan stink takes a long time to go away.

Kevanf14 months ago

To prevent rusting on the inside of a tank just pour some auto cavity wax in the tank before you build it up. Warm the tank first then pour some liquid was inside and swirl it around. Leave it to set and you're done.

-CCCP-9 months ago

You can just use one female. The two female thing is indeed a bad example. However, if you own an air compressor, you most likely have a box of stuff like blowgun tips and quick connects. If you keep losing your adapter for the female one just store it with your air compressor stuff. I will be using my tank a LOT, so I will use the adapter at least once a week.

-CCCP- -CCCP-9 months ago

Wouldn't you go looking for the quick fill adaptor too?

-CCCP- -CCCP-9 months ago

Wouldn't you go looking for the quick fill adaptor too?

Garra231 year ago
can you take a 1lb tank and convert it to an air tank
-CCCP- Garra239 months ago

Yes you can! Just attatch a disposable propane bottle to NPT adapter (Search this up in amazon, get one with 1/4 inch male NPT). Screw in the Tee fitting and you are good to go!

mr. clean1 year ago
The only other problem with leaving the standard propane valve on there is that some have a safety shutoff built into the valve so if you were to try to use a lot of air at once the valve may shut itself off, to reset it you have to turn the valve off and then it should reset in seconds or so.

I figured this out by trying to use a wheat burner and when I would hit the lever to ignite it the gas would shut off.
txsmoke1 year ago
I had a dry rotted o-ring on my grill. I leaked. The filling place I use gave me a replacement just for the asking.
Is it not a 'idea' to use a household cylinder for a year, and then cycle that back into the supply from the gas men? If you have gas heating, then you'll go through a fair few cylinders, so why not us one that is already checked, and of a known suitability, then after a year or two swap it out for a 'new' one?
as far as rust preventative couldnt you spray in a dose of latex sealer or some such coating?
glorybe3 years ago
This worries me a bit. Air tanks must handle moisture and normally have a drain valve to get rid of water. A propane tank may not face the same issues with moisture as propane probably has no water content. They also have no drain valve. I worry that these tanks may over time suffer loss of strength and explode. It could be very, very serious.
Perhaps an engineer that designs air tanks could chime in on this.
scob89 (author)  glorybe3 years ago
That is easy to fix, For the smaller standard grill size tanks, I just flip them upside down about once a month and open the valve, So far, no big moisture issues or water buildup, however there is always a bit of water in the main compressor tank when I open the moisture drain

As for the big tanks, it may be a bit harder to flip them upside down to drain them, but I have built my own air compressor system out of 4 of the big house tanks mounted upside down on the shop wall. For the compressors I have 3 motor/compressors that fill the tanks up pretty quick, and stop at 125 PSI.

Also keep in mind that these are heavy duty tanks that hold Propane, Propane stores at over 200 PSI. I think the tanks are pressure tested at around 600 - 700PSI, Not sure on that.

As a general safety, if the tank is pretty rust on the outside I don't repaint, instead I just replace the tank. My big 4 compressor has been working for the last 2 years with no problems at all.
heathbar644 years ago
Brilliant!! Sometimes the simplest idea's are the best. the thought that immediately came to my mind is, Why not use the newer hands free grill connector?  Of course, the whole idea is using old obsolete tanks, so probably most wouldnt have that syle of valve.  
scob89 (author)  heathbar644 years ago
I used the old style connector because it will work on both the old and new style tanks, Plus you really don't need a tool to put the old style on, I have always hand tighten mine and never once had it leak.

On tanks the had propane in them yet, I always use the proper wrench to tighten, it's not big deal is air leaks, but if propane leaks it can have some negative effects.
heathbar644 years ago
 I meant tool free connector, not hands free.  Why can't I edit my comment once I post it?
heavydeath5 years ago
(removed by author or community request)
 the big valve has a tirevalve type thing and i found schrader valve keys but they are to short any help
scob89 (author)  heavydeath5 years ago
A better option would be to use a PVC pipe air chamber with a 1" ball valve connecting the air chamber to the barrel. This type of tank would not have a very good amount of air flow for a spud gun. I bet the spud would only fly about 10 feet maximum before it hit the ground.

If you really wanted to use this tank, the best thing to do would be to get a old style propane torch that just screws onto the tank and remove the burner part so an air hose could be connected.
You could use this tank as an auxiliary tank to increase the air compressor capacity
Be careful of used tanks as they are being discarded for a reason, out of date for safety may be the biggest of them. Tanks can and do rust from the inside and around the welded areas. Where I work we sell bottles and propane and we have had safety bulletins about a tank blowing because of a weak weld. Luckily no one was killed. Test the tank by tapping it with a non-sparking hammer around the bottom and near the welds while listening to the difference in sound. You may also want to flood the tank with water to rid the tank of the smell before using it for an air tank. After which you may also want to add some alcohol to the tank to get rid of the water then let it air dry in the sun to remove the alcohol.
I use the hundred pounders for my house. How much pressure are they rated for? I really dont want to find out the hard way .
According this a propane tank fill with propane can see vapor pressures as high as 257psi. Use that as a guide at your own risk.
Thanx, I'm sure not to need that much pressure but its good to keep in mind
DIY Dave5 years ago
Where did you get the ball valve?
scob89 (author)  DIY Dave5 years ago
That one I got out of the scrap pile at work, you can normally find them at just about any store that has plumbing supplies.
DIY Dave scob895 years ago
so it is a pumbing part?
scob89 (author)  DIY Dave5 years ago
Yep it's just a standard threaded 1/2" plumbing ball valve.
DIY Dave scob895 years ago