Miller Electric

Welding Discussion Forums

Home » Resources » Communities » Welding Discussion Forums

  • If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.


Announcement Module
No announcement yet.

what's the safest way.......

Page Title Module
Move Remove Collapse
Conversation Detail Module
  • Filter
  • Time
  • Show
Clear All
new posts

  • what's the safest way.......


    What's the safest way of cutting an old oil tank or propane tank .



  • #2
    Fill the tank with water and have at it.


    • #3
      WyoRoy gave you one way of safely cutting containers that have contained explosive substances. I have another that you may not like, and I certainly mean no disrespect or am I discounting your abilities. My suggestion is take it somewhere where they know how to safely do it and see if they will allow you to observe, or if they will give you details on how to do it. I personally do not think this is an area for someone to be going it alone just learning the process. Whatever you decide, just remember it will not matter one bit what process or how well you were doing if something goes wrong. Stay safe and good luck.


      • #4
        If you got the slightest tinge of doubt or second thoughts....


        I won't cut on one, don't care if someone's cut a thousand of them & knows the best way to do it.

        Nope, not me.

        Only takes one time being on the wrong end of a situation gone bad to kill you, or at the very least, leave you maimed for the rest of your life.

        I know a guy who works for a company that refurbs rail cars & does a lot of tankers. They had a propane car come in that needed a section of the tank replaced. They steam cleaned it out like they always do, but didn't get on it immediately afterwards. A few days later, the crew came in & a guy started to cut the bad section of tank out. Propane was so deeply absorbed into the metal, that more began to seep out in the days following the steam cleaning.

        The inside of the car exploded & flipped over on it's side.

        Luckily, the cutter didn't get seriously injured, but it scared the heII out of him. I was surprised he didn't get killed. My buddy said he's glad he works on the other end of the shop & never has to do jobs like that.

        Sure, I heard the story secondhand, but he's not the kind of guy that makes stuff up so if the "experts" wanna refute it, take a long walk.........

        After hearing that, there's NO way I'll go near any tank. NO matter how "safe" it may be.

        IMHO of course.
        Last edited by 7A749; 05-03-2010, 06:36 PM.


        • #5
          Safest way would be to use abrasive string underwater. Might take you a year or two though. Just fill it with water as suggested.


          • #6
            No experience to speak of on propane tanks but there is a LEL meter that measures gases. I would also say if your hesitant then don't. Also an internet forum is not the place to get advice on something like this as some people will state things as fact which aren't. I'm not saying any of the above info is good or bad, just saying it's impossible to tell the bs from the good sometimes & you don't want to find out the hard way..
            Last edited by MMW; 05-03-2010, 08:31 PM.


            • #7
              Let it air out for as long as you can, run car exhaust in it for a while (nuetralizes atmosphere), fill it with water then use a cutting wheel on a grinder to make your first cut. I cut my whole tank on my smoker with a cutting wheel but i think that once you make an initial cut you can go to fire if you want to (if its still filled with water that might get interesting). Using a sawzall or jig saw might be a safer method but take several blades.


              • #8
                Originally posted by joshcarlegis55 View Post
                Let it air out for as long as you can, run car exhaust in it for a while (nuetralizes atmosphere)
                Sorry Josh thats the biggest myth on the planet. Car exhaust has lots of LEL (the stuff that burns) in it. Don't care if its diesel or a gas engine it does. I just retired from a refinery where we did stuff like this almost everyday. Our LEL meters used to go off just walking up a roadway and a fork truck or crane drove by and what was it (the meter) picking up? the LEL in the exhaust. I wouldn't do it either in my shop anyway at the refinery no problem. They have the proper stuff to clean it and the meters to check when clean to be sure without a doubt its clean. Don't make yourself front page news. Have a ring rolled and start with new steel its easier and safer...Bob


                • #9
                  Safest way is a scrap shear on an excavator after the tank has been properly remediated. Anything else is just foolish and stupid.


                  • #10
                    I have cut one.

                    It was an old underground tank. Dug it out, by hand too. 200 gal tank.

                    I had taken off the valves and etc and left it out in open for several years. Not sure how many years at the moment, but over three anyway.

                    No odor smell to it, I filled it up with water. Got busy with other things for a few weeks. Just made sure that it stayed full of water.

                    Since it was an underground tank, it had two 18 inch tall pipes welded to it for the valves and etc. I just left them on for the moment. The water level in tank was all the way up in the 18 in. tall pipes.

                    I cut on the tank at the top of the tank near the upright pipes. The water put out the torch flame shortly after I burned into the tank. No fire or big boom, just extingushed the torch. Water drained out of the standing pipes and I finished making the cut on the tank. About a foot long cut. I also cut off the two upright pipes.

                    That left me with a 200 gal tank full of water. So I drained it by making another cut on the tank near the bottom on one end of the tank. Took a bit longer of course than the first cut, but I got it drained.
                    Last edited by Harvuskong; 05-04-2010, 12:31 AM.


                    • #11
                      Evacuate it with a high vacuum pump running outdoors with a blower blowing the propane away from the pump's motor. When you reach a really good vacuum, say, 500 microns as indicated by a thermistor gauge, break the vacuum. All residual propane has been boiled to a gas state (provided the container no longer has any cold spots) and will no longer leech out of the metal. The concentration of propane is now 0.07% (30 times leaner than the lower flammability limit) and the mixture is completely non-flammable.

                      The key is that propane is only explosive at concentrations between 2% and 10%. Below 2% you can blow it right into a flame and it won't burn. Above about 10% concentration in air, it will not burn either... but it will further dilute in air and become an explosive mixture.


                      • #12
                        cutting a propane tank

                        I can only speak from my personal, first hand experience, so take it or leave it.
                        I have cut dozens of propane tanks. 20-100lbs tanks. I got my method from professional in the propane tank industry.
                        As follows:
                        empty tank outdoors
                        remove valve outdoors ( make your own wrench)
                        fill tank with water, empty
                        fill again and let sit over night (12-24 hours)
                        cut away with plasma or zip cut or torch.
                        The water displaces the LP gas and ensures its completely forced out. As well it rinses out some of the residue left from the chemical odorent that is added.
                        I've not experienced any sort of "poof".
                        Do only what you're are comfortable doing. I don't advocate taking forum advise as gospel. I can only relay my first hand experience.
                        Urban legend can muddy the waters of truth.
                        Since this topic comes up quite often on many forums I may try to light an un-prep'd tank remotely. I've got a good size property. I'll bury the tank up to the top and sand bag it. Will video tape to record the result.
                        Good luck


                        • #13
                          Originally posted by bert the welder View Post
                          Since this topic comes up quite often on many forums I may try to light an un-prep'd tank remotely. I've got a good size property. I'll bury the tank up to the top and sand bag it. Will video tape to record the result.
                          Good luck
                          That would be a real "shock and awe" type of video.

                          I would suggest letting the local sheriff know in advance about when you remotely light that thing up. He will be having to deal with calls reporting what sounded like a bomb explosion or plane crash or etc and etc.


                          • #14
                            Like telling kids to run with scissors! Phone around see how many welder's will do this. I had a friend who got real lucky when he was an apprentice cutting a gas tank because farmer Bill has done hundreds of them. Common sense people !! Use it ! What is so **** important about cutting a propane bottle in half anyway?? If you want and have to cut one in half safely drive yourself down to Wal-Mart and go to the garden section and buy a brand new one that has never had propane in it! Some of them old bottle's had liner's in them and it wouldn't matter how much you washed them out "THE POTENTIAL FOR EXPLOSION " is still there! Jef


                            • #15
                              You're right of course. I won't argue with you over your advice/warning in the least...You are absolutely correct.

                              When I was the first one to reply I was giving a lesson I learned from my dad/Farmer John when I was a kid. Neighbor brought over a hot water tank to cut open with our O/A torch to use as a slop trough for his pigs. The only way my dad would let it happen was to have the tank filled with water beginning to end. Dad wasn't worried about propane or oil just unspent gas from the cutting torch flame accumulating in the tank during the cut. So I guess even a brand new tank from Wal-Mart just might be a problem.

                              These days with the Internet everyone is a potential expert and everyone wants a quick answer. Reasoned replies in the past to posters queries have been dismissed like water off a duck's back by the person posting because they weren't the 'right' answers, weren't easy, cost too much, etc. A simple "Don't!!!" won't stop the potential Darwin Award winner either. So what do you do?


                              Special Offers: See the latest Miller deals and promotions.