[pofo]

Back to the original plan. I take it you want to use the oxygen cylinder for compressed air. I assume you only have capability to fill the tank with air from a regular 120-150PSI compressor, nothing more.

If that's the case, then the tank won't hold much air. You will have a heavy tank that won't last long. Not worth the effort.

If you plan on filling it to 20,000psi, as normal for an oxygen tank, then adding a hole is not going to work as the tank will explode from the pressure due to the hole you put in it.

Either way, it is not going to be very useful. Why not find a bigger tank that holds a decent amount of air like a 20 gallon tank from an old compressor?

[universalfab]

You could try a 55 gallon steel drum, had a buddy I know try it and he's still breathing...

[Kipper]

I know that this could be dangerous, but if it is possible, i'd like to try it.

I have this used disaposable oxygen cylinder that you buy from home depot or lowes...

It is empty and i have a small plan on running my little torch on compressed air and propane.

In a nutshell, i am trying to figure out how to safely drill a hole into the cylinder.

Is this possible. If yes, any idea how do i go about doing that?

Sure it's possible....I'd use an air drill on the disposable (if the valve is still present) if the valve is out...anything goes plasma electric drill chop saw etc.

I wonder why the guy in the video didn't point the bottle at his neighbours and knock the valve off with a sledge hammer

[tlharris]

Call me crazy, but I think the video narrator / investigator just plain missed the mark on this one. I don't believe the cylinder exploded at all - no signs of such in the workshop. Nothing even remotely black, signed, scorched, etc. There is plenty of metal deformation, for sure. I think he's mistaking this for 'melting'. But this is the kind of thing I'd expect to see with a sudden release of compressed gas. What the mechanic attempted was fundamentally foolish and inexperienced. Or at the very least, a terrible lack of judgment. THERE IS NO WAYto safely 'slowly vent' 2000+ psi through steel threads. He's lucky to have only lost an arm. The defective cylinder should have been taken back to the supplier for service.

Which leads me to what others have already stated or alluded to : the oxygen cylinder *won't* explode. It's the high-pressure gas you have to worry about. Simply bleed it. Yes, outside is better. Leave it open for a couple of days, or fill it with a bit of compressed air if you wish. All you'll be left with is a *possibly* *slightly* oxygen-rich steel tank. Always leave a closed vessel open to atmosphere if possible when you're working on it, just so it doesn't heat up and build pressure. If you're really paramoid, open to atm and THEN remove the valve completely. Bandsaw, drill, torch, whatever you're comfortable with.

BTW... when welding on tanks that are currently full of nasty things (yes, it happens all the time, and it's not to be taken lightly) there are several precautions that use or combine as appropriate for the situation:

- as one user suggested, filling with water. This can't always be done, but *liquid* is typically safer than *gas*. A full gasoline tank won't explode - it doesn't have enough oxygen. One full of gasoline VAPOR and AIR, will, in fact explode spectacularly.
- N2 blanket. Purge the oxygen and fill with nitrogen. In a closed vessel (only one way in and out) you have to fill/bleed/repeat until you're confident the O2 has been displaced.
- CO2 blanket. Variation on the above, usually accomplished by stuffing the container with dry ice. Remember you still have to leave an opening, so as the dry ice turns to C02, it can displace the air out.

Even when you know what you're doing, you still typically have multiple people, checklists, and a brief prayer session of some type before you strike the first arc on a full pipeline or storage tank.

THE INFO ABOVE IS OFFERED FOR INFORMATION ONLY.... DO NOT TRY THIS AT HOME