Hey Kent. I gotta real heart-stopper for 'ya. Earlier today I was
drilling a 'decomissioning' hole in a disposable propane tank (later
to be cut up for use as a small crucible, but that's another story),
well I figured I'd pop two so I can have a little fun with the 1atm
gas left sitting inside.. Grab a straw and a lighter and blow flames!

You'll be interested to know that, no matter how hard I tried to get
oxygen into the bottle, I never got internal combustion.

Another neat trick is taking your air+propane torch set lean, put it
down the neck of an empty milk jug, blast it for 10 seconds (until it's
full of propane), then light it off (use something long BTW). Fwooom!
To add to the enjoyment, you can pick up the jug and then light it off -
rocket propulsion!

No matter what setting, rich nor lean, have I had any faster than a
slow burn. The HDPE jug remains intact, though slightly warm.

BTW... anyone with a propane foundry can try a similar cute trick. Put
some loose leaves in the furnace, turn on the gas, then light it from
the top (I 'spose you could do it from the bottom too).

Tim

--
"That's for the courts to decide." - Homer Simpson
Website @ http://webpages.charter.net/dawill/tmoranwms

"Kent Fowler" wrote in message
...
On Mon, 01 Dec 2003 20:27:21 -0500, Bob Engelhardt
wrote:

Kent Fowler wrote:
...
And what happens if you just happen to burn a little bitty
hole in the tank with your torch?

You get a little bitty amount of propane oozing out (it's not under any
pressure) and burning _outside_ the tank (remember there's NO AIR in the
tank).

...You still have the vapor and the vapor is what is going to ignite
first if you
happen to put a hole in that thin tank with a torch.

Wrong - 1. vapor won't ignite without oxygen, 2. There's nothing "thin"
about a 100# tank.

How do you know there was not O2 in the tank? Remember, he
said he left the valve open over nite, I believe. Could have gotten
enough air to take it out of the rich range into the flamable limit
range. You are " assuming" no air had gotten in there. So is Dave.Was
the mixture checked with an flammable limits meter? No. So you don' t
know, Dave doesn't know and I don't know. Therefore I'm not going to
put any flame on it cause I don't know. I know now,what you guys are
going to do. BTW, you would be suprised how thin those tanks are.

Dave:
The vapor inside my tank isn't going to spontaneously ignite.
It can't, without oxygen. So again, where is the risk

The little bitty hole and a heat source such as
your torch will sure do it.


Braaahh! Wrong again! A little bitty hole will not introduce air into
the tank. Using an OA torch to cut a tank can introduce oxygen
depending upon the mix, but Dave was using a propane torch - there's no
way that's going to put a hole, "little bitty" or otherwise, in the
tank.
Braaaah all you want, stranger things have happened. That's why they
call them " accidents". I see you guys like to push your luck. , You
know for sure there was no O2 in there, don't you. And you know for
sure Dave didn't have a mapp gas cylinder instead of propane. Hell,
the next time Dave wants to put a torch to a cylinder, you might stand
next to him. Smart guys like you fellows surely can't be wrong.

Regards, Kent