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.
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.