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

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.

Step 2: Drill Baby, Drill!

Now it is time to find a drill bit and a drill, you want to have a drill bit sized anywhere between 1/8" and 1/4" 1/4" is the MAX size you can go. and it is the size that I went with.

That tiny hole serves very well as a pilot hole for the drill bit too, so no worries about going off center, Now put the brass tube with the thread collar removed in a vise with the tiny hole facing UP, you just need to snug down the vise some, not too much or you will crush the tube and the thread collar will not go back on.

Now once all that is done, you have the main part of the adapter done. The rest is up to you how you want it and how it will suit you best, I will give a few examples in the next steps and a couple bad ones as well.

Step 3: Basic

The basic adapter is just a female hose coupler screwed right on to the adapter, remember what I said about standard threads. The threads on the adapter are the EXACT same as on standard air hose fittings. Yes that is right, this means some much as well.

Here is the most basic adapter you can get.

Step 4: Qiuck Fill

Using that tire valve to fill the tank too a bit too long for me to stand there filling the tank, so I made a second adapter to just fill the tank quickly.

Step 5: In Line

Here is the final product.

Having the quick fill was nice, but it was kind of a pain to switch back and fourth between adapters to use the tank. So I made a in line adapter so I could use that tank while it was filling, plus since I kept the quick fill adapter, I can fill two tanks at the same time.

Step 6: Bad Example

This was a Big tank I converted a while back, It will hold its pressure forever, it's been at 80PSI for about 2 years now. It is a bad example, because It need a male to male adapter to fill it, and I always need to go looking for the adapter to fill it back up, such as life, I never use it because of that.

Step 7: Stock Up and Enjoy

Now go out and find some propane tanks and you will have plenty of compressed air on hand.

The tanks will smell like propane for quite awhile, but the smell does go away after several time of filling and using the tanks.

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    31 Discussions


    2 months ago

    You forgot the 1st step, which is to make sure all the propane is removed. Adding air to a tank with propane could create the conditions necessary for an explosion. Even a little bit of propane with some air could be bad...even with no apparent heat source to ignite...there is static electricity t worry aboot.


    4 years ago on Introduction

    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.

    1 reply

    Reply 2 years ago

    Is warming the tank a good suggestion ? Boom? A lot of DIY amateurs read this, is this a good suggestion ? With all respects, perhaps a rinse with detergent ?


    7 years ago on Step 2

    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.

    2 replies

    Reply 2 years ago

    Just turn the tank upside down for a minute or so and then vent the air out of the tank very quickly. If you have an air hose attached just keep it lower than the tank. This will blow the water in the tank and hose right out. Easy as pie !


    Reply 7 years ago on Step 2

    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.


    2 years ago

    Just turn the tank upside down for a minute or so and then vent the air out of the tank very quickly. If you have an air hose attached just keep it lower than the tank. This will blow the water in the tank and hose right out. Easy as pie !


    3 years ago

    Slightly off topic, but wondering if anyone can suggest a way that I can be acertain a stanar propane tank isn't pressurized? I'd like to remove a head off of a tank that I'm 99% sure is empty. (I'm making a hank drum) I can open the twist valve, and no sound or hiss, but i believe there's a 'safety' valve that only allows a release when it's attached to a hose/stove/whatever - which I don't have. Can I take it into a home depot and just attach a hose and try the valve? Is there a special tip that engages that safety valve?

    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

    1 reply

    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.


    6 years ago

    can you take a 1lb tank and convert it to an air tank

    mr. clean

    6 years ago on Introduction

    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.


    6 years ago on Introduction

    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.


    6 years ago on Introduction

    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?


    7 years ago on Step 2

    as far as rust preventative couldnt you spray in a dose of latex sealer or some such coating?


    9 years ago on Introduction

    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.  

    1 reply

    Reply 9 years ago on Introduction

    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.


    9 years ago on Introduction

     I meant tool free connector, not hands free.  Why can't I edit my comment once I post it?


    Reply 9 years ago on Introduction

     the big valve has a tirevalve type thing and i found schrader valve keys but they are to short any help