Propane tank

[Anti-GMAW]

I like the idea of using an air compressor tank and the original fittings that somone suggested earlier. It just might be cheaper than having the propane tank modified.

[JBFab]

while I haven't done it on that large of a vessel, I have done projects with 20 lb. propane cylinders before. I take all of the fittings out, fill with water, drain, fill with water again and begin working with it full of water. Now, when you throw the pressure vessel thing into the mix, a simple rule applies, if you doubt your abilities in any way, DO NOT ATTEMPT IT.

[Cowbungus]

I am involved with a community project where a large volume of air pressure is required to blow an old time steam whistle.
We are estimating we will require around 100 reserve gallons of air to make it blow.
One of the "expirts" on the committee believes he can obtain a 200 gallon propane tank for this purpose. I questioned my ability and courage to weld a bung into this large enough to provide the required air supply. I am thinking
2" or so.
Anybody have any experience welding on used propane tanks, I am not sure I want to do it or allow anybody else to get hurt doing such a job.

A commit here. First I was in the propane business for nearly 30 years. The ordorizer is an oil based product that will impregrenate into the metal pores. The ordorizer is flammable also. Now to be safe! forget it . In order to render the tank safe it must be steamed out to remove all the ordorizer. How old is the tank?? is it butane or propane. butane has a working pressure of 100-125 psi while propane has a working pressure of 200-250psi working pressure depending on the year of mfg. Another thought has the tank been out side for years without having any propane in it. This starts the rusting process inside the tank due to condensation. In turn the rusting will weakin the metal because you are talking about using the tank for pressure. Folks use the old tanks for BBQ pits and thats ok, but I would sure hesitate without a long thought of what could happen now or later on when you put the pressure in the tank. Do not remove the pop off valves if you decide to build this set up, it is for your safety.