Safety Issue

[Gordon Campbell]

In my humble opinion
An inert gas should be used to remove
an explosive mixture from a tank to be welded or cut with a totch, such as carbon monoxide from a exhaust pipe, would be the inert gas.



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[Rotate]

Is there any "safe" way to cut open a spent propane tank. I referring to the small tank used for propane torch. Also, would it be any safer to cut open an oxygen tank of the same size? Right now, I don't have any use for them but it would be nice to know the proper method, if there is one.

Albert

[Thrud]

Safety being the key issue here, it think it would be to anyones own benefit not to do things that organizations like OSHA or Workers Compensation take exception to and forbid in the work place. There would be fewer home accidents as well if we all did that.

And yes, sometimes deadly risks have to be taken when there is no other choice. It is the responsibility of every thinking rational person to consider their actions and the consequences of possible failure.

[Ragarsed Raglan]

Gordon,

You got it right ~ if you want to gas weld a fuel tank use a flex pipe from the egzost pipe of a nearby car with the engine running. Gasoline vapours will only burn at between 9:1 and 20:1 Air Fuel Ratio. Egzost gas is pretty inert (that's why you have EGR to reduce NOx!). A guy I knew welded many a motorcycle gas tank by purging the vapours this way. He's still around!!

[docsteve66]

Q: Is there any "safe" way to cut open a spent propane tank. I referring to the small tank used for propane torch. Also, would it be any safer to cut open an oxygen tank of the same size? Right now, I don't have any use for them but it would be nice to know the proper method, if there is one.
Albert
A: Cut many ofthem. never had a pop from even one. Here is my method.
1. Try not to cut a tank that is completely empty. All ways a chance of air/gas inside- to make a pop. (truth is I say this only to keep others happy)
2> open valve and shove tank top into warm water. When the bubble stop you know the tank is empty of propane.
3. Drill a hole where you wish to cut. Now you know the tank has no propane in it (excepting at atmosheric pressure) and no air mixture. Use abrasive disk and cut. In my opinion, the disk heats the tank, thus the gas, expelling gas as you cut. Sparks all over the place but never a small pop.

Despite regulations to the contrary, I refill the tanks when i wish. We cook out side in a motorhome- travel months at a time. Use lots of bottles of propane. The net wt of the bottle is marked on out side. Weigh the containers, add marked wt (usualy 14 Oz) and I subtract 2 Oz for safety. Hang bottle below a large tank of propane (large bottle up side down to deliver liquid) and let the juice flow till the tank weight is what you want. Be VERY sure not to over fill.

I have never had a valve leak- the filler consists of an old torch fitting with a schrader valve screwed in one end, sameon oither end except its a POL fitting fortnak. connecting tube is the line used for refrigeration test set. I still test each refilled bottle by putting end in water and watching for bubbles.
Cut off cylinders make good chimes (tuneby cutting to sound right). some wont ring- dead for some reason.

Raglan: I never thought of using exhaust gas. Probably it is safe in a modern car because of the cat converter. but the old cars, at idle were rich. The old guys remember (surely) screwing a sparkplug and Model T spark coil into end of exhaust pipe and watching it belch flames.

[This message has been edited by docsteve66 (edited 06-12-2002).]

[Thrud]

Steve
Come to think of it there is a good way to do it - water jet cutting.

[docsteve66]

<font face="Verdana, Arial" size="2">Originally posted by Thrud:
Steve
Come to think of it there is a good way to do it - water jet cutting.</font>

Dave, I been wanting to ask if any one has had experience with water jets. I haven't even seen one - been retired since 1984, so lots of things I haven't seen. Hell of a note when a man claims age as excuse for ignorance

Steve

[Thrud]

Steve

I had a 6061-T6 1" plate cut to size on one. It was worth the doughnuts! The jet is about 50,000 psi or higher and they can use grit in the water as well. The top edge is slightly curved down from the pressure and the exit (bottom) had a slight burr. The plate edge looked like it was sand blasted and had a slight irridescent quality. Neat.

There was a Plasma/Water Jet installed in the Detroit area - first one in North America. It can do either on the same machine for about th same cost of the plasma cutter alone.