Moderators: Random Orbital Bob, nev, Noel, Charley, CHJ

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By hawkeyefxr
#1195485
I like them, a great idea though i have to warn people who want to do this, DON'T. There will still be gas in an empty cylinder. I have seen the after effects of exploded cylinder and i would not want to be within 500 yards of one going off.
BOC had a acetylene cylinder that had had a blow back, there was a 3ft split in the bottle.
Not sure on propane bottle but acetylene bottles when full have 400lbs of gas pressure in them, if they ignite that is the same as a 400lbs bomb. That was drummed into me in my apprenticeship.
By sunnybob
#1195501
its worse than that, propane gas has to be compressed by200times volume to make it liquid.

that makes 1 litre of liquid equal to 200 litres of petrol, except propane burns fiercer than petrol.
A gas tank will stop producing gas when the tank is around 20% still liquid (even more if its cold outside). A 100 litre propane tank will still have almost 25 litres of liquid inside, even when the gas fire connected to the outlet goes out.

DONT DO IT!
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By monkeybiter
#1195514
I think the method of making them safe is to remove the valve/plug in the neck and fill them with water, possibly leave for a day before emptying and commencing any cutting work.
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By Sheffield Tony
#1195522
That's a sane approach. A friend of mine making barbeques out of some took them out into the field, retreated to a safe distance and shot a hole through them with his rifle. Not very sane, but no explosions, which in context of what has been said above is quite surprising.
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By monkeybiter
#1195533
Copper/Lead versus steel - no spark, just rapid depressurisation.

I once used a .22 pistol to spot through a hole in a thick wall for waste pipe alignment. No explosion there either, even when SWMBO found out.
By hawkeyefxr
#1195650
sunnybob wrote:its worse than that, propane gas has to be compressed by200times volume to make it liquid.

that makes 1 litre of liquid equal to 200 litres of petrol, except propane burns fiercer than petrol.
A gas tank will stop producing gas when the tank is around 20% still liquid (even more if its cold outside). A 100 litre propane tank will still have almost 25 litres of liquid inside, even when the gas fire connected to the outlet goes out.

DONT DO IT!


Well said.
One a cold day with the valve removed! liquid could still be there.
Didn't know that about the amount of liquid to gas ration, interesting.
I once over filled an R22 refrigerant bottle and the safety valve blew off in the car, i jumped out and dump liquid on the road, then drove off, unfortunately it left a 3 foot dia frost patch in the road, in the middle of summer. This was many many years ago before it was illegal to release refrigerant gas to the atmosphere.
By sunnybob
#1195654
I forgot to mention you need bronze spanners because one spark and youre gone.
Put your mobile phone a long long way away.
Wear clothes that you want to dump, because if they get soaked you will NEVER get the smell out
Propane is heavier than air, so don't do it next to a drain or basement as the gas will collect in there and catch you later.

When we emptied large tanks (500 to 15000 litres) we had to use a flare stack set 30 yards from the tank and pump nitrogen in Untill the gas sniffer showed minimal at the stack. And that was just to move them offsite!

I'm happy I'm done with all that, good luck to any who wants to try
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By Robbo3
#1195751
Lot of scaremongering going on in this thread.
I've removed hundreds of butane & propane cylinder valves - all with metal spanners, emptied the cylinders, then revalved, filled & purged the air.
The heavy ends, ie the residue that accumulates, stinks because of the stenching agent added to odourless flammables at the refinery.
By NazNomad
#1195774
As mentioned above, no problem if they are properly purged.

I've cut a door in one before, but how would you go about cutting those intricate designs? Plasma cutter?

Some of those are really detailed, could they have been CNC'd?
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By CHJ
#1195788
NazNomad wrote:I've cut a door in one before, but how would you go about cutting those intricate designs? Plasma cutter?

Some of those are really detailed, could they have been CNC'd?
I assumed they must be although I could not get a definative answer when trying to pin down the stall holder, just my husband makes them.

Family does have one and some other fire basket/torch products from them so may be able to find out.

Very welcome when at a social gathering with friends in Bavarian winter temperatures but I'd much prefer to be seeking some shade with a few exotic birds around rather than trying to find the optimum distance to emulate a Döner kebab rotisserie.
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By monkeybiter
#1195793
CHJ wrote: i'd much prefer to be seeking some shade with a few exotic birds around rather than trying to find the optimum distance to emulate a Döner kebab rotisserie.


Does SWMBO know about this?
[Somebody had to say it :twisted: ]