[ArtcoInc]

You must have talked to the wrong welding supply places. Any welding supply worth their weight in anything carries oxygen. It's needed for so many applications.

Don't go to a medical supply place. The bottles are too small, the price is too high, and I have heard that some medical oxygen has water added (pure oxygen will dry our your lungs).

As for which size bottle to get, get the largest you can lift. A full 125 (or whatever the designation) is a large-ish, heavy bottle. The next size larger is about the same height, much larger in diameter, and twice the weight. How much can you lift? The cost to fill a tank twice the size is not twice the cost. If your budget allows, you might want to consider having two tanks. It sucks to run out of oxygen on a Friday night, when you have a lot of work to do on the torch, and the gas place doesn't open again until Monday.

You will go through much more oxygen that you thought you would. On my little Minor Burner, I'll go through either 3 or 5 (I can't remember which) 125's of oxygen for a single 20# BBQ size propane tank.

Buy or rent? Run the numbers, and see what works for you. Even though you 'own' a tank, most people don't have *that* tank refilled .... they exchange it. So, it's mostly a matter of cost. And do shop around ... prices for oxygen do vary.

Delivery is good! Delivery is very good! There probably is a delivery charge. You'll have to determine if the convenience is worth the extra cost.

Good luck! And, you can always call me down here in San Jose (you're in the East Bay, right?) if you have any questions.

Malcolm