Safest way to cut a propane tank for making a smelting pot?

[baogongmeo]

Freon tanks will start becoming rarer and rarer over the next few years. New production systems are all going to a propane based (flammable) refrigerant.

Brilliant!!! What could go wrong???

[country gent]

Older industrial freezers and coolers used Ammonia when they filed the ammonia displaced the oxygen in the building. One failed in this area and half a small city was evacuated for several hours.

[Rickf1985]

Freon will displace the Oxygen but it is not poisonous unless it is introduced to flame at which point you will get flourine gas. Ammonia is poisonous. Very old systems used ammonia. I find it very hard to believe that new systems are going towards propane. That makes no sense at all when flammable refrigerants were outlawed back in the 80's when they started to ban HFC's. My license is still good but I have been out of the refrigeration business for many years now, most of what I did was automotive. Any kind of flammable refrigerant in an automotive system is extremely dangerous due to the high heat under the hood. It was butane back then but same thing, you are above the flash point just from the underhood heat.

[Pablo 5959]

I used a hand held band saw. Had 2 half’s in about 8 minutes.

[Moleman-]

The fridge in our house is a kenmore but was made by LG according to the repair tech that came out to replace the compressor. Seems there is/was a class action lawsuit because the fridge was designed to run off of butane but couldn't pass the UL criteria or something to that effect so they adapted them to run off of R134a which caused premature compressor failure. We opted to have a generic industry standard compressor unit put in v/s the more expensive "it's for sure going to fail again" LG/kenmore unit. Been working fine for 2 years, but I'll never buy another kenmore or lg product.

Now back to the LP tank. There will likely be some clear oily sludge that stinks like the chemical used to give propane a smell. I water purged mine with soapy water several times and still was getting an oil slick mixed in with the rinse water. When the tank was cut apart there was an ounce or two of sticky clear goo at the bottom of the tank that had to be scraped out. Wear rubber gloves or your hands will stink.

[Brassmonkey]

Valve on mine spun off without much trouble, filled with water to displace any vapors that was months ago, I'll get to cutting it and setting the rest up someday.

[GregLaROCHE]

I take off the valve fill with water till it flows out and cut with angle grinder and cutting wheel , smells but is no chance of fire or explosion .

Water will leak out as cutting , no big deal same way I would use a stone cutting blade on skil saw when cutting concrete around old window sills , water keeps the dust down and water keeps it from having any thing to burn.

That’s the way I have done it.

[Ed_Shot]

I removed the valve from the propane tank (not too hard as I remember) filled it with water and let it sit for two days then drained it and cut it just below the weld seam with metal cutting blade in a cheap 4" angle grinder.

[Rickf1985]

Well, at least the one I tried the valve is not coming out due to age and rust and I am not spending a lot of time and energy on something I have no use for afterwards. So it is getting a hole drilled in it and filled that way and then cut with some form of destructive tool. I have about 8-9 tanks out of date so I am not turning them all in, I can't afford to do that at 30.00 a tank! I already have a 100lb. tank that I use to heat my garage.

I will drill a hole the right size for a valve stem and pop one in (I have hundreds left over from my shop) and then I will hook up the air chuck to that for a while to clear out any residual gas and then I will bore it out with the unibit and fill it with water. I can do all of that and expend a tenth of the energy trying to fight that valve off!

[oley55]

I have about 8-9 tanks out of date so I am not turning them all in,

No doubt there are differences from state to state and there are the really old style with female LH threads, but my local Florida propane company routinely recertifies my old tanks. I just had 4 tanks filled last week and all of them needed to be re-recertified. I have no idea what the fail/recertify criteria is, but they are required to record date codes and what not from the stamped numbers on the handle/guard. I did turn in an old female LH threaded tank, but is was so rusted and pitted on the bottom I didn't think it would be suitable for any use.

[Farmall-130]

Safest way to cut a LP tank is - don’t cut it. Get a 1/4 keg beer tank. They’re stainless steel & the cheap. No risk involved in cutting it.

[Rickf1985]

I just looked through Facebook Marketplace real quick and Beer kegs are running 40-50 bucks. Not exactly cheap. And not all kegs are stainless, some are aluminum.

[G W Wade]

I couldn’t get the valve out, it broke, so I slowly drilled a hole with a hose running on that spot and then filled it with dawn and water. Left it a day then flipped it over in the sun for a day, then ran compressed air through it. Cut with a sawzall.

Lots of ways to mark a line on a cylinder. I usually wrap a strip of paper, but can just tape a marker to any outside corner and spin the tank against it.

Had the same problem with an old propane tank. Took it out to my range at 100 yard and used 22/250 on the valve. Tank was empty. Filled with water and used sawsall on the seam around the middle. Plenty big for my use. GW

[Hdskip]

It is never a bad thing to err on the side of safety in matters like this.

[Rapier]

When I bought this farm, I discovered an old 500 gallon propane tank buried in the ground near where the old house had burned (burglary/arson case). I had to dig the tank loose in the ground with my backhoe and then loaded it up on my equipment trailer for transport to the salvage yard, across the border. I could not figure out a need for a 500 people BarBQ.
Before I got rid of it, I went through the whole business of how to cut. It is pretty much water with soap, flammables permeate the steel, you can not with 100% safely just drill or cut it.

[HogRider666]

Being nervous about cutting any gas tanks I decided to use an old air compressor tank that we had in our workshop. I still took precautions but felt more comfortable.

[JimB..]

Well, at least the one I tried the valve is not coming out due to age and rust and I am not spending a lot of time and energy on something I have no use for afterwards. So it is getting a hole drilled in it and filled that way and then cut with some form of destructive tool. I have about 8-9 tanks out of date so I am not turning them all in, I can't afford to do that at 30.00 a tank! I already have a 100lb. tank that I use to heat my garage.

I will drill a hole the right size for a valve stem and pop one in (I have hundreds left over from my shop) and then I will hook up the air chuck to that for a while to clear out any residual gas and then I will bore it out with the unibit and fill it with water. I can do all of that and expend a tenth of the energy trying to fight that valve off!

Oh, I just swapped a few really old ones out at the Blue Rhino or whatever. Their propane is high, but you get to use their tank for free and can refill is elsewhere.