cut open a propane tank

[Jim Timber]

Thanks!

2 tanks, a section of diesel exhaust pipe and some other aluminized drops I scrounged from an exhaust shop, some channel, plate, flat stock, and a lot of electrode. Never did get around to putting the latch on it, but I have the spring knob for that.

I ended up extending the stack a bit since it didn't draft well that short. I've been planning on putting this in a deer stand someday - still haven't built the stand yet either.

 

[ch1ch2]

That would be one nice deer stand.
I had a friend who built on 16 ft high with tv couch coffee pot.

 

[ch1ch2]

I may have to look for another tank and build something like that.

 

[Jim Timber]

I had plasma'd off the top end on several of these a number of years ago for making into little vertical oriented stoves and just never did it after my prototype with charcoal failed to produce any appreciable heat for the amount of fuel I had in it. So I took a pair of those for my donors and mated them up. I used the open end of the tank I cut the radius'd shoulder off to mark where to cut the one to fit inside it and leave a minimal seam. You could cut these to make a butt joint, but the lap is easier to align and holds itself from warping when you put the final weld in.

The two tanks together allows for 18" front to rear depth, so it'll hold a 16" split. Just need to get a little fire started in there and then add bigger wood. What's nice about the design is that you can dry your wood on top before feeding it if it's a little wet.

I also added some vent holes to the bottom and boxed in the air path with the intention of adding a gate to control the fire and a sweeper to pull the ashes out with, but found that I get a better burn varying the door's opening and leaving the bottom vent wide open. Probably an issue of too much fire for the firebox volume - but it still works.

I was lucky in scrounging a whole mess of these tanks (had over 30 at one point) back when the OPD valves were being phased in and no one was converting the old tanks so people just tossed them or gave them away. Now I use them for all my waste motor oil and store it to dump on my brush piles for accelerant.

 

[ch1ch2]

"Now I use them for all my waste motor oil and store it to dump on my brush piles for accelerant. "

Shame on you; the Politically Correct police are going to shake their fingers at you, and they will look down their nose's at you, and they will talk about you.

 

[Jim Timber]

I'm actually going to design a sprayer that uses a Schrader valve to pump the headspace with air pressure and has a dip tube to allow me to squirt my fire from a safe distance using the already full tank of oil.

 

[dfkrug]

A propane torch also helps burn off the mercaptan residue and neutralize the stink. Plasma cutting does wonders as well. I've never found a remedy that'll clear it out better than fire though. Even after years, that dose remains in the tank with the valve off. Just remember that if you're going to use one for an air reservoir (they work great for them btw). Your air will stink for a long time unless you cook that stuff out first.

That is my experience, too. Cursed with a sensitive nose, I really want to eliminate that stink.

For LP or gasoline tanks, as well as 55gal drums, I remove all caps and ventilate with compressor air
after removing liquids. With 2 holes, I can blow in one, and ignite the exhaust from the other, using
a propane torch. If there are flammable gases, you get a flame. Stop the air when the flame dies
out. No woof or explosion. Works like an O-A torch. No water.

 

[ultrarunner]

You always have the best advice... and simple to do.

Much cheaper than flooding with Nitrogen...

 

[FTG-05]

They can only explode if they're sealed and able to make pressure. Worst case scenario is you get a little flame thrower off the bung until the fuel is burned off with an LP tank. Other substances like your resin are a different animal.

I'll say it again - drain the tank down, remove the valve, then you can deal with the residual gasses. Always, always, always, always take the valve out first. You can fill it with water if you want, but it's been my experience that gravity does a good job.

A propane torch also helps burn off the mercaptan residue and neutralize the stink. Plasma cutting does wonders as well. I've never found a remedy that'll clear it out better than fire though. Even after years, that dose remains in the tank with the valve off. Just remember that if you're going to use one for an air reservoir (they work great for them btw). Your air will stink for a long time unless you cook that stuff out first.

Maybe I missed it: If you're going to use it as an air tank, how do you "cook" the smell out first?

Like another poster here that has done it, I plan to repurpose several 100 lb propane tanks as air tanks. I really don't want to deal with the smell but I really, really don't want to deal with an exploding tank. "Cooking" a former propane tank seems to be a lot like the latter.

Thanks

 

[Jim Timber]

Flame. You could do it with a rosebud up in the bung.

 

[Berniep]

That is my experience, too. Cursed with a sensitive nose, I really want to eliminate that stink.

For LP or gasoline tanks, as well as 55gal drums, I remove all caps and ventilate with compressor air
after removing liquids. With 2 holes, I can blow in one, and ignite the exhaust from the other, using
a propane torch. If there are flammable gases, you get a flame. Stop the air when the flame dies
out. No woof or explosion. Works like an O-A torch. No water.

For things like gasoline and oils they collect residue in the pores of the metal and this will come out as a flammable vapor when you cut it with a torch. not much of a problem until you get a stoichiometric mix (https://en.wikipedia.org/wiki/Air–fuel_ratio) and then you get a big boom. A good way to avoid this is to use any kind of device to move the air in and out of the tank. like a constant stream of air from a compressor or a running engine exhaust. Although, as already stated, if it is not tuned well a gas engine, and possibly any engine can contribute to the problem rather than help.
Just a few miles from me a guy was killed cutting the end out of a tank open with a torch. The tank was about head high with two sizable caps that had been open for at least 20 years. There was no discern-able odor and he had almost made the complete cut in one end when it blew.

 

[Egon]

Bernie: there have been a lot of deaths from exploding barrels and tanks.

General note: in an industrial setting one will find some pretty specific guidelines about what can be done with discarded containers.

 

[Egon]

Bernie: there have been a lot of deaths from exploding barrels and tanks.

General note: in an industrial setting one will find some pretty specific guidelines about what can be done with discarded containers.

 

[ch1ch2]

For things like gasoline and oils they collect residue in the pores of the metal and this will come out as a flammable vapor when you cut it with a torch. not much of a problem until you get a stoichiometric mix (https://en.wikipedia.org/wiki/Air–fuel_ratio) and then you get a big boom. A good way to avoid this is to use any kind of device to move the air in and out of the tank. like a constant stream of air from a compressor or a running engine exhaust. Although, as already stated, if it is not tuned well a gas engine, and possibly any engine can contribute to the problem rather than help.
Just a few miles from me a guy was killed cutting the end out of a tank open with a torch. The tank was about head high with two sizable caps that had been open for at least 20 years. There was no discern-able odor and he had almost made the complete cut in one end when it blew.

Sound like filling with water is the best way. Know from experience how porous metal really is.

 

[Egon]

You always have the best advice... and simple to do.

Much cheaper than flooding with Nitrogen...

There are places and times the nitrogen gets delivered by trailer trucks and requires a pump truck to get it into the system.

 

[FTG-05]

Flame. You could do it with a rosebud up in the bung.

For things like gasoline and oils they collect residue in the pores of the metal and this will come out as a flammable vapor when you cut it with a torch. not much of a problem until you get a stoichiometric mix (https://en.wikipedia.org/wiki/Air–fuel_ratio) and then you get a big boom. A good way to avoid this is to use any kind of device to move the air in and out of the tank. like a constant stream of air from a compressor or a running engine exhaust. Although, as already stated, if it is not tuned well a gas engine, and possibly any engine can contribute to the problem rather than help.
Just a few miles from me a guy was killed cutting the end out of a tank open with a torch. The tank was about head high with two sizable caps that had been open for at least 20 years. There was no discern-able odor and he had almost made the complete cut in one end when it blew.

Yea. On second thought, the smell can't really be that bad. Considering the alternative, of course.

 

[Jim Timber]

Flushing it out with water won't remove the mercaptan. You can have it filled to the brim, dump it out, fill it again, dump, fill, dump, fill, dump = still smells!

 

[Al 2]

No suggestions as to best way to cut a tank but this is a link to a company that makes some good looking pits and may give you some ideas.
Look here: Muskoka Fire Pits

 

[pat32rf]

I once picked up some staledated 100lb tanks and needed compressed air storage as my pump is a little small. I pulled the valves and vented in the sun, filled with water etc, then welded on extra legs for stability and height, plus a 1/2' pipe coupling for a drain in the bottom. Next I filled them with cold water and screwed a pressure gauge, ball valve assembly into the top while it sat out in the sun. I added a bit of extra heat to bring the pressure up to 300psi. Result was an air tank to hold 125psi that had been tested to 300psi,

 

[pmsmechanic]

I've never done it myself. I've read where people wash the tanks out with soap and water. Then plumb the exhaust from a diesel engine into the tank while cutting. A lot of people say never to use the exhaust from a gas engine.

I have filled a gas tank with mig gas before welding on it. I don't know if it was the right thing to do or not but I'm still alive.