Process to cutting an old propane tank

[A-one]

I ran across an old propane tank that somebody was giving away. Wanting to try my hand at putting a smoker on a trailer, I couldn't let it pass. The only problem is, I don't know the procedure to cut it safely. I have an uncle that tells me to fill it with dish soap and water and go to town. A friend that has done it says the same thing. I've read quite a few posts on the internet that say fill it with water, along with white a few posts of other methods.

Decided I would come here since I'm a member, and you all might love me enough to help me not blow myself into however many pieces I can possibly be separated into. Just looking for advice tip stay safe.

 

[poncho62]

I would think filling with water would be the way to go. I take it you are going to cut it with a cut off blade in a grinder rather than a torch......lol

 

[California]

Please have your wife video this. Put her at a safe distance. Tell her how to post the video here.

 

[California]

I was surprised long ago to find a welder willing to weld up a leaky seam in a motorcycle gas tank. He said simple, just wash with soapy water then fill it with water. I didn't stick around while he did it. But he did nice work.

 

[aussiebushman]

It is quite easy. Best to rinse the tank out with soapy water then use an angle grinder. Cut off one end to make the door and fabricate a custom hinge. Note the air intake tube below the main chamber - you need to make a couple of a removable components so you can remove the slag

 

[A-one]

Please have your wife video this. Put her at a safe distance. Tell her how to post the video here.

Next county is a safe distance as far as I'm concerned.

 

[A-one]

I would think filling with water would be the way to go. I take it you are going to cut it with a cut off blade in a grinder rather than a torch......lol

I don't have the slightest idea what the plan is. But it seems torch vs grinder and water... neither is the best choice.

 

[poncho62]

Look at this thread....

Used Engine Oil Catch Pan & Tank From Scrap

I just finished making myself a used engine oil drain pan & tank from scrap LPG tanks. Took me longer to edit the video than it did to make the project! The video runs 16 minutes, here it is...

www.weldingsite.com

Craig is cutting up BBQ size tanks.

 

[PILOON]

Propane is heavier than air so park the opened tank with valve hole facing down.
If in a hurry blow compressed air into that inverted tank to push out any remaining propane.
Have done this method a fair number of times and still around to post, LOL.
At worst you'll occasionally get a slight 'poof' if any propane is left over but nothing drastic.

 

[Sherwood]

ive made a forge this way, remove valve, fill with water, slosh around some , empty water then use a grinder, when the valve is removed, it cant explode, but it wont anyway, have fun.

 

[A-one]

Ok. After checking out you guys posts and talking to a few people, the jitters are just about gone. I guess not understanding will make for a little nervousness. Fill with water (and some soap to help clean) and slosh around. The water is heavier than the propane, therefore purging any leftover propane from the tank. Should be good for all the cutting I need to do after that. Thanks everybody. I'll get started on it soon. Will try to remember to start another thread and post pics.

 

[Craig]

Look at this thread....

Used Engine Oil Catch Pan & Tank From Scrap

I just finished making myself a used engine oil drain pan & tank from scrap LPG tanks. Took me longer to edit the video than it did to make the project! The video runs 16 minutes, here it is...

www.weldingsite.com

Craig is cutting up BBQ size tanks.

And you will see in that video I demonstrate in detail exactly how to safely cut in half any tank that use to contain flammable/explosive contents!

 

[A-one]

And you will see in that video I demonstrate in detail exactly how to safely cut in half any tank that use to contain flammable/explosive contents!

??????

 

[Yomax4]

It won't be an issue. I cut one open to boil animal skulls last year. Take out opened valve, Dawn soap and water. Dump it out and drain and flush out well and go after it with the Plasma Cutter, Torch or Cutoff's. All above suggestions will work. Good Luck. " KaBoom" !! just kidding..

 

[Bearskinner]

Pretty much the consensus of everyone else also. I had to weld a couple tabs on a gas tank and repair a crack. Removed the tank, filled with water multiple times, flushing it out fully. Let sit, open in the sun to dry out for a day. Before getting the grinder wheel near it, I put a piece of newspaper in the fill spout lit it and hid! No poof, or flare ups, thankfully. Ground out the bad spot, welded it up and replaced the weak tabs with hardier ones. Still scary thinking about welding on a fuel tank

 

[A-one]

I think the jitters are gone as far as cutting this tank is concerned. I think I'll cut it in half so I can make a couple of smaller mobile smokers.

 

[MarineScott]

ive made a forge this way, remove valve, fill with water, slosh around some , empty water then use a grinder, when the valve is removed, it cant explode, but it wont anyway, have fun.

Yes, this is how I do it. DON'T step in the water afterwards, that smell stick to your shoes.

 

[Craig]

I have read the problems are not from a common BBQ or RV style propane tank, but with the large stationary tanks.

The smaller tanks have a short life and do not get re-filled very often compared to a stationary tank.

On the other hand, a stationary tank might have a service life of 30 years and be re-filled a couple times every year or more. What can happen is the rotten egg smell may condense back into a thin oil on the walls of the tank. This will seep into pores in the metal, corrosion, etc. That make it more difficult to wash out.

The tank gets retired, someone wants to cut it up into a big BBQ, they wash it out with soap and water, etc. and that will get rid of the LPG for sure. But then they start cutting it with a torch...

What happens?

The thin oil heats up, becomes vaporized, and is now in a flammable mixture within the tank! Most likely there is NOT enough energy for an explosion of significant proportions. But at the very least when it sets off you're gonna need to take a short day to go change your shorts. On the upper end of possibilities, if the tank is mostly cut through when the oil vapor lights off then there could be enough energy to toss heavy metal around and hurt someone, or worse!

I have a 1,000 gallon LPG tank I purchased from a LPG service. They sold it to me 'certified' as 'clean of LPG' by soap/chemical bath rinse. But I was warned it could 'flare up' if cut with a torch and to just take precautions for such a situation. Every hot day for three years I could smell the rotten eggs in that 'clean' tank!

Ultimately, the message I think needs to be emphasized is this: If you are not absolutely certain of what you are about to try, if you are not absolutely confident in the technique or process you are about to try, if you have any doubt about the outcome, THEN DON'T TRY IT!

This is just an opinion - I am NOT giving advice.

 

[Yomax4]

I have read the problems are not from a common BBQ or RV style propane tank, but with the large stationary tanks.

The smaller tanks have a short life and do not get re-filled very often compared to a stationary tank.

On the other hand, a stationary tank might have a service life of 30 years and be re-filled a couple times every year or more. What can happen is the rotten egg smell may condense back into a thin oil on the walls of the tank. This will seep into pores in the metal, corrosion, etc. That make it more difficult to wash out.

The tank gets retired, someone wants to cut it up into a big BBQ, they wash it out with soap and water, etc. and that will get rid of the LPG for sure. But then they start cutting it with a torch...

What happens?

The thin oil heats up, becomes vaporized, and is now in a flammable mixture within the tank! Most likely there is NOT enough energy for an explosion of significant proportions. But at the very least when it sets off you're gonna need to take a short day to go change your shorts. On the upper end of possibilities, if the tank is mostly cut through when the oil vapor lights off then there could be enough energy to toss heavy metal around and hurt someone, or worse!

I have a 1,000 gallon LPG tank I purchased from a LPG service. They sold it to me 'certified' as 'clean of LPG' by soap/chemical bath rinse. But I was warned it could 'flare up' if cut with a torch and to just take precautions for such a situation. Every hot day for three years I could smell the rotten eggs in that 'clean' tank!

Ultimately, the message I think needs to be emphasized is this: If you are not absolutely certain of what you are about to try, if you are not absolutely confident in the technique or process you are about to try, if you have any doubt about the outcome, THEN DON'T TRY IT!

This is just an opinion - I am NOT giving advice.

I have an old 20# propane tank that I converted into portable air tank. After 30 years of use it still has the rotten egg smell. Not sure it it ever goes away. I had to sand blast the 100# tank I cut open.

 

[Lis2323]

Not propane, but many years ago a neighboring greenhouse farmer had an employee cutting up BIG decommissioned oil storage tanks.

Bad news is he was blown half a city block away and landed on a roof and unfortunately died.

Good news is it wasn’t my mom’s house.