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Cutting the bottom off a propane tank?


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  #1  
Old 01-12-2008, 10:47 PM
Brickman Brickman is offline
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Default Cutting the bottom off a propane tank?

What is the safest way to cut the bottom off a 100# propane tank without it blowing up . thanks ron brown in central illinois
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Old 01-12-2008, 11:16 PM
J.B. Castagnos J.B. Castagnos is offline
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Default Re: cut propane tank

If you have access to argon or co2, you can drill a hole in the bottom and flood it with the gas until it's well purged, can't explode without o2. If you can get dry ice into it, let it set until the smoke is overflowing, it's safe to cut then.
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Old 01-12-2008, 11:47 PM
Kevin O. Pulver Kevin O. Pulver is offline
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Default Re: cuting a propane tank

Hire someone else to do it?
Recently I read about someone dropping some dry ice in a fuel tank and waiting for the CO2 to fill the tank. I don't know how you could get any dry ice in here. Could you remove the fill valve, fill it with water, and use an angle grinder? Or remove the fill valve, fill with dry ice and use a plasma cutter or torch? Kevin
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Old 01-13-2008, 12:16 AM
Eric M. Eric M. is offline
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Default Re: Cutting the bottom off a propane tank?

Fill it with water through the fill valve. If it's one of the old style tanks with the bleeder screw, open that to release the air/gas. Once it's full, empty it and refill it with water. Drain it again and you're good to go.
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Old 01-13-2008, 01:43 AM
Patrick McNallen Patrick McNallen is offline
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Default Re: Cutting the bottom off a propane tank?

I wouldn't cut the damned thing, period. I wouldn't cut it, drill it, chisel it, grind it, or grind on it.
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Old 01-13-2008, 07:55 AM
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Doug Kimball Doug Kimball is offline
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Default Re: Cutting the bottom off a propane tank?

I'm with Patrick on this one. Drilled into the ammonia side of a propane refrigerator with an 1/8" bit ... propane had leaked into refrigerant side. My arm became instantly bald from my wrist to my arm pit & tingled for two or three days. Luckily no permanent damage.
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Old 01-13-2008, 11:15 AM
Rick McKay Rick McKay is offline
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Default Re: Cutting the bottom off a propane tank?

Here's the safest method that I can come up with.

Take the valve off and turn the tank upside down to make sure any liquid is drained. Then let the tank sit with the whole open for a week so it can breathe. After a week has passed, take the tank out into a wide open area, set the tank vertically on two 12" cement blocks, pile a buch of scrap wood all around the tank, maybe about a two to three foot pile all around the tank. Set the wood on fire and get the heck out of there!! The heat from the fire will cook out any flammable residue making it safe to cut after it has cooled. If any gas residue is impregnated in the steel, it will burn off, and so long as the tank is setting vertically, the force and flames from from the blast will blow out the hole in the top, keeping the tank safely standing vertical. I watched our local gas station/parts store burn a few years ago, and when the acetylene tanks (there were several) got hot enough there was vertical blasts of flame that shot about 50 feet in the air from the gas venting out of the safety valves.....long story short, the tanks were still standing upright after the fire was out, and no tank blew up (by this I mean ruptured) or moved from their resting place.
A frient of mine built a shop stove out of a large Propane "pig" which is about twice the diameter of a 100 lb tank. His tank was taken from the rubble of a cottage that had burned to the ground, as it had been right against the outside wall of the building. He figured that since it got cooked at intense heat for quite a while, he should be able to cut into it. He cut right into it with an acetylene torch with no problem at all.

Good Luck, and be SAFE!!!!

Rick

Disclaimer:
Writer accepts no responsiblity for the outcome if anyone chooses to follow the above mentioned procedure. The text is for entertainment only etc., so on and so forth, yada, yada, yada, this, that and the other thing.

(sorry for the legal disclaimer, but that's the world we now live in)
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Old 01-13-2008, 11:32 AM
Kevin O. Pulver Kevin O. Pulver is offline
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Default Re: Cutting the bottom off a propane tank?

Brickman,
Fill the thing to the brim with Tetra Ethyl Lead.
Patrick will then come over and open the thing up for nothing.
That is one substance he's not afraid of.
(see other thread about how lead got in gas)
Kevin
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Old 01-13-2008, 04:16 PM
Patrick McNallen Patrick McNallen is offline
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Default Re: Cutting the bottom off a propane tank?

MMMMM! Tetraethyl Lead! Rich and TASTY! Great on supersize hot dogs, Bologna sandwiches, Buffalo Wings, and those 5 pound deep-marbled charcoal-braised steaks!
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Old 01-13-2008, 10:57 PM
Nathan K. Nathan K. is offline
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Default Re: Cutting the bottom off a propane tank?

HI,
I wanted a nice funnel to drain used oil into a drum so i took an old 20# bottle removed the valve and filled it with water and left it out to freeze. The next day I put it in the lathe and cut the center weld, took the bottom welded on a nipple and its a nice funnel for draining pails. I should have left it out longer though as it didn't freeze quit deep enough and it started leaking in the lathe so I couldn't quite cut the weld backup strip free so I had to finish with a chisel Nathan.

Try at your own risk!
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Old 01-14-2008, 09:44 AM
John A John A is offline
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Default Re: Cutting the bottom off a propane tank?

.
The safest way to cut on a lp tank is first make sure all lp gas product is removed and down to zero PSI. (LIQUID AND VAPOR) Remove service valve, fill it 100% full with water, dump, fill again, dump, the water will remove any residual vapor, purge with a non-flammable inert gas, and depressurize.
If you are not comfortable with the way it looks fill it with water a couple of more times.

CAUTION- What ever green or oily mixture that comes out of that tank depending on the age is going to stink to high heaven.
I reccomend NOT rinsing the tank out near the house.
Maybe at a neighbors? oops.
Clorox bleach will help neutralize the odor.
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Old 01-14-2008, 11:28 AM
Patrick McNallen Patrick McNallen is offline
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Default Re: Cutting the bottom off a propane tank?

I didn't know that Clorox would neutralize that government stink in propane. You might not want to put Clorox into a tank that may have flammable residue in it, since Clorox is an oxidizer and might cause a flash or explosion. I can't think of any use for a propane tank with a hole in it that would lead me to take the risk of cutting into one. If you have the means to cut into a propane tank, you have the means to construct about anything that you could make out of a propane tank without risking your life doing it. Old air tanks often have oil residue in them, too, and at least one professional welder was blown all over town working on a tank that was known to have never contained anything but water.
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Old 01-14-2008, 06:52 PM
Brickman Brickman is offline
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Default Re: Cutting the bottom off a propane tank?

i have been doing a little reaserch on this so this is how i think i will cut it rinse out with water 2 or 3 times then fill it half way up with water and put in some hydrochloric acid swimming pool grade then fill it up with water let set overnight rinse out again refill with water and acid let set overnight again, rinseout again when i cut it use a gas powered chop saw with 14 inch metal cuting blade while i have the exaust from a 5 hp brigs straton going to the bottom of tank through a 3/4 inch copper tubing that has been runing for a while . it will be a few days before i get to do this so i will let you know how it went ron brown in central illinois.
thanks for all the good advice and conserns
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Old 01-15-2008, 07:48 AM
Ray Freeman Ray Freeman is offline
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Default Re: Cutting the bottom off a propane tank?

I have welded fuel tanks after draining them and rinsing them out with water and detergent. Then run the exhaust of an engine through it for 20 minutes.
As long as you get the oxygen out of it and have it purging with inert gas there is not a problem.
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Old 01-15-2008, 11:15 PM
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PFT PFT is offline
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Default Re: Cutting the bottom off a propane tank?

A friend of mine made a gas tank for a generator from a propane tank. He just went to BJ's and bought a new one that had never been filled. No problem.
PT
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Old 01-24-2008, 03:49 AM
baddog0690 baddog0690 is offline
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Default Re: Cutting the bottom off a propane tank?

Just last week we built a snow plow for my four wheeler and used a old propane tank for the blade.. we unscrewed the valve, then put a hose to the exhaust on my bike stuck it in the end where we unscrewed the valve, let it run for a few minutes, then drilled a pretty good sized hole in the other end, let the bike run for another five to ten minutes, and cut off one end with a metal skill saw.. worked good, but while welding later you could tell there was still some propane in the metal as it would flare up alittle every now and then.. hope it helps..

BTW what are you making??

and heres a link to 3 pages of photos of the snow plow we built if interested.. http://baddog0690.myphotoalbum.com/v...umName=album13
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Old 01-27-2008, 10:51 PM
Brickman Brickman is offline
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Default Re: Cutting the bottom off a propane tank?

well i got the bottom off the propane tank today, and did it like i said i was going to do , except i used my portable band saw to cut it with instead of the gas powered saw .when done i took a rag with some gas on it ,light it on fire and droped it in the propane tank with a long handle and there was no fire except the gas on the rag so i guess the acid cleaned the tank out pretty good. thanks for all the advice
ron brown in central illinois
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Old 01-28-2008, 12:45 PM
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kerogas kerogas is offline
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Default What was the acid for ?

Did it not have any rust in it yet ?
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Old 01-29-2008, 09:42 AM
Brickman Brickman is offline
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Default Re: Cutting the bottom off a propane tank?

no rust in the tank it looked like new inside ,and it is a very old tank, ron brown in central illinois
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Old 01-29-2008, 12:19 PM
kchmn kchmn is offline
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Default Re: Cutting the bottom off a propane tank?

I used to take the valve out then let the tank sit out in the sun for a week or so. Then you move it to somewhere away from other things. have a long hose on your torch and put something big and heavy between the tank and the torch. I used to park my service truck between them with the box towards the tank. then prop the torch up in cuttingposition next to the tank. Light it up and get behind the truck with the torch tanks, when the tank starts shooting sparks near where the torch is heating shut off the fuel gas. If in a minit or so the tank is still there you can now safely cut it up. If it isn't you'll need a bulldozer to fill in the hole before you try it again,LOL. Do not try this at home
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