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Posted: 4/16/2002 8:33:52 AM EDT
I need to weld a crack in a 1000gal bulk fuel tank? It last had gasoline in it, but is now empty. I asked a welder around town what his reccomendation was? He said he would fill it full of fuel and weld away? I don't think I want to do that. I am concerned about the fuel vapor inside the tank igniting when welding. Anythoughts on how I can get this thing welded up. Oh yeah, I will be using a mig welder on it, if that helps. Thanks
Link Posted: 4/16/2002 8:40:10 AM EDT
[Last Edit: 4/16/2002 8:41:35 AM EDT by Stormbringer]
The welder is RIGHT!!! LISTEN TO HIM!! I have helped my dad weld gas tanks... The first thing he checked was that it was FULL of gas!! As you know gas is just flamable..... GAS VAPOR IS EXPLOSIVE!!! If you have a full tank it may start to boil but that is all. If you have an empty tank....... Well just let me say its been good to know you. If you do not want to use the tank for gas in the future just fill it with what ever you will use it for. This will force out the vapors
Link Posted: 4/16/2002 8:42:19 AM EDT
I second Stormbringer. The less headspace you have between the gasoline and the top of the tank the better.
Link Posted: 4/16/2002 8:47:34 AM EDT
1000 gallons of gasoline? I would not risk that. What is so hard about filling it with water? I know it will be a PITA to drain but if it is currently empty, filling it with water is quite inexpensive and drying the tank afterwards is relatively easy with a shop vac and long wand. At $1.31 a gallon here, you could buy a pre-ban instead of filling it. Plus, if you are fixing a leak, you never know what additional leaks may spring due to heat. What ever you do, do not weld on empty tanks.
Link Posted: 4/16/2002 8:53:31 AM EDT
So if I fill this thing with #2 diesel, I can weld on it safetly? Even if there is alittle leaking (very small amount) of the diesel where the crack is? Just wanting to make sure I heard this correctly.
Link Posted: 4/16/2002 8:54:02 AM EDT
I do not know about you keith....but I always try to keep water OUT of my gas tanks......makes running the engine REAL HARD! But if he is not going to put gas in it anymore that is a good idea. If he is worried about more leaks......well perhaps its time to get a new tank
Link Posted: 4/16/2002 8:55:55 AM EDT
Your welder is right to an extent. I've done several of these and his method does work. If applicable you could purge the fumes with carbon monoxide (exhaust)and get a stonger weld.
Link Posted: 4/16/2002 9:01:13 AM EDT
Yeah, I don't really want to put water in the thing, athough they have filters--I always seem to get problems anyway. Fuel will be going back in it--not gasoline, farm grade (non-tax) diesel. Tank is only about a year old--the crack was inflicted from a front-end loader bucket. That is not right--front-end loaders don't cause cracks in fuel tanks--dumb@ss operators do.
Link Posted: 4/16/2002 9:01:43 AM EDT
Originally Posted By LgAnimalVet: So if I fill this thing with #2 diesel, I can weld on it safetly? Even if there is alittle leaking (very small amount) of the diesel where the crack is? Just wanting to make sure I heard this correctly.
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This is correct. Welding the part of the tank above the fuel level is when things can become dangerious.
Link Posted: 4/16/2002 9:02:09 AM EDT
BULLSHIT! These people are going to get you killed bro! Go rent you a "K" bottle of argon and pipe it to your tank with a top vent hole. Open the bottle up and let the heavier than air argon displace the fumes. Then weld. Wouldn't hurt to rent a sniffer from a safty company too.It will cost you about $40 for the bottle and save you life. Argon is inert and will make a better shield gas on the back side than the exaust fumes. Exaust fumes are good, just not as good as argon.
Link Posted: 4/16/2002 9:06:59 AM EDT
[Last Edit: 4/16/2002 9:10:05 AM EDT by LgAnimalVet]
Alright, we are going to light this firecracker after lunch. Fuel truck is on its way out. I hope your guys are right cause the tank is sitting right next to 1000gal gas tank and 4 1000gal diesel tanks. If you are wrong its gonna be a helluva boom.
Link Posted: 4/16/2002 9:23:28 AM EDT
I'm with you pangea. Any inert, denser than air gas – or even water – is a whole lot safer, especially with other nearby fuel tanks. Hope I don't hear about this on CNN!
Link Posted: 4/16/2002 9:25:14 AM EDT
What happened??
Link Posted: 4/16/2002 9:30:22 AM EDT
Good luck man... If it were me, I'd go with the Argon bottle and fill the tank with Argon gas, venting unwanted explosive vapors out the top... There was an incident a few miles from here several years ago... A guy was in the process of cutting up an old 1000 gallon gas tank that had been EMPTY for several years, and was just sitting on a guys farm... All I will say is, the explosion rattled windows miles away, and the guys body was found several hundred yards away with half of the tank... Good luck !!!
Link Posted: 4/16/2002 9:32:06 AM EDT
[size=4]Hire a professional welder that is experienced with welding fuel tanks.[/size=4] There's no sense in getting blasted into the stratosphere unnecessarily. A few extra dollars spent could well save your life.
Link Posted: 4/16/2002 10:43:40 AM EDT
Link Posted: 4/16/2002 10:56:53 AM EDT
I've "welded" (brazed) fuel tanks in the car, in the shop. Approved method is to make sure that the tank is filled to the brim. Doesn't hurt to have a fan directing any stray vapors from the leak out the open shop door. The gas leaking from the crack will burn, but if there is no vapor, like from a fairly empty tank, then there is no explosion. Been there, done that, still have all my issued body parts.
Link Posted: 4/16/2002 11:06:11 AM EDT
[left]They are right, fill it completely full of fuel and weld away. Fumes from gasoline are only flammable in concentrations between about 6% to 18%. Any gas fumes above or below that concentration will not ignite. [/left]
Link Posted: 4/16/2002 3:04:32 PM EDT
Well we finally got it done. I had one hell of a time trying to convince anyone working for me to do it (I was not going to do it). I told them that I had obtained very reliable information on a firearms site on the internet that guaranteed me that they would not get blown up. They didn't look too convinced. Anyhow, got the tank filled up and the fuel man from Co-Op, myself, and the rest of the crew sat across the road watching poor Bill(who I threatened to fire) sweat like two rats F'n in a wool sock as he started the bead. It was pretty funny, when the diesel would spark up a bit on the outside, he'd drop the welder and run like hell, we'd laugh at him and shout obscenities. But in the end, he did a very good job for his ability. And we didn't get on CNN for destroying half the midwest.
Link Posted: 4/16/2002 3:12:00 PM EDT
welding = heat + gas = big BOOM!
Link Posted: 4/16/2002 4:02:15 PM EDT
If it were me. I would have handed you the torch and said "if its totally safe then you should have no problem doing it yourself" pangea has the smartest procedure here. Many a person has gotten killed doing this kind of thing just to save a buck. I hope to God you give this welder one hell of a bonus in his next check. Id rather look for a new job than risk my life to save the boss a few bucks.
Link Posted: 4/16/2002 4:29:49 PM EDT
Originally Posted By Citabria7GCBC: welding = heat + gas = big BOOM!
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Exactly WRONG... flame + Gas vapour= boom Heat + Liquid gas = Hot liquid gas. Heck next time you run your lawn mower for a while open the gas cap....probably the gas will be boiling away happily. I know that my chainsaw gas boils all the time. LgAnimalVet......glad your guy is A O K!!
Link Posted: 4/16/2002 4:34:32 PM EDT
Originally Posted By LgAnimalVet: Well we finally got it done. I had one hell of a time trying to convince anyone working for me to do it (I was not going to do it). I told them that I had obtained very reliable information on a firearms site on the internet that guaranteed me that they would not get blown up. They didn't look too convinced. Anyhow, got the tank filled up and the fuel man from Co-Op, myself, and the rest of the crew sat across the road watching poor Bill(who I threatened to fire) sweat like two rats F'n in a wool sock as he started the bead. It was pretty funny, when the diesel would spark up a bit on the outside, he'd drop the welder and run like hell, we'd laugh at him and shout obscenities. But in the end, he did a very good job for his ability. And we didn't get on CNN for destroying half the midwest.
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Hahaha, Thnaks for the best laugh I've had all day![pyro]
Link Posted: 4/16/2002 10:38:35 PM EDT
What I don't get is how an open flame does not catch the flammable liquid on fire. Obviously it works, but I still don't get it... HUMONGOUS balls on the hired help BigPigDoc.
Link Posted: 4/16/2002 11:27:52 PM EDT
Good thread there, Lg AnimalVet. I was a believer there for a long time – thanks for the laugh!
Link Posted: 4/17/2002 4:43:57 AM EDT
Originally Posted By GlockA-Molee: What I don't get is how an open flame does not catch the flammable liquid on fire. Obviously it works, but I still don't get it... HUMONGOUS balls on the hired help BigPigDoc.
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Oh it will catch fire alright!! But it will NOT explode! Now I would not attempt to weld one that has gas POURING out of it. Most cracks sort of weep fuel. Actually the flames help to "light up the work area". Once you have welded the crack closed it cuts off the flow and the flames go out. Remember you need Fuel Vapour AND Oxygen for an explosion. This way you have just liquid gas so you only get fire.
Link Posted: 4/17/2002 5:12:41 AM EDT
Welding Containers In two recent incidents in Ontario, explosions during welding fuel tanks killed three workers. In the first, two workers welding a 150-gallon diesel fuel tank were fatally injured. In the second, a 500-gallon gasoline tank exploded during welding, killing a worker. These accidents would not have happened if proper cleaning, purging and testing procedures had been followed. After the first incident, it was discovered that the diesel fuel in the tank was contaminated with gasoline. As little as two per cent of gasoline in diesel fuel can create an explosive mixture in a closed container, with the flashpoint (the temperature at which a spark or other ignition source will cause an explosion) falling below the temperature inside the container. For any hot work such as welding or cutting a container that may have contained flammable or combustible material, the following minimum precautions must be taken: The container's internal layout must be determined to make sure that fittings such as baffles will not interfere with cleaning or purging. The container must be drained and cleaned using appropriate methods. To determine whether draining and cleaning has made the container safe, its interior must be tested with a combustible gas detector both before hot work begins and periodically during the work. However, some containers cannot be drained and cleaned well enough to make them safe. Such containers may be made safe by purging and inerting with an inert gas, but only if these precautions are taken: Recognized procedures and proper equipment must be used. The oxygen level inside the container must be monitored with an oxygen analyser and maintained at essentially zero for the duration of the work. To accomplish this, if steam is used the hot work must be completed before the container begins to cool. If inert gas is used then the purging must be continued throughout the duration of the hotwork. Workers must be made aware of the limitations of the inerting process. NEVER ASSUME A CONTAINER IS CLEAN OR SAFE. MAKE SURE THAT IS IT MADE SAFE AND THAT ITS SAFETY IS VERIFIED BY TESTING BEFORE ANY HOT WORK BEGINS. NOT FOLLOWING THIS RULE IS LIKELY TO KILL YOU! Occupational Health & Safety 1995-07-24
Link Posted: 4/17/2002 8:16:58 AM EDT
I'm glad you didn't become a Darwin candidate. However, I'm not sure I would have used internet advice to bet other people's lives on. Filling a tank as much as you can with fuel is not the safest way to do it. I'd try contacting an underground storage tank company and ask them what method was the best. I hired people who know what they were doing to cut up our fuel tanks. They used inert gas and dry ice. In addition, they had an explosive meter to keep tabs on the fuel/air ratio. They also regaled me with stories of idiots who have died welding or cutting fuel storage tanks while they were removing mine. It's kind of wimpish to threaten to fire somebody because they don't want to do something your too afraid to do yourself. Don't try to tell me you knew it was safe because you were supervising from across the street. Anyway, glad it turned out okay.
Link Posted: 4/17/2002 8:43:10 AM EDT
[Last Edit: 4/17/2002 8:47:09 AM EDT by LgAnimalVet]
Originally Posted By Guess: It's kind of wimpish to threaten to fire somebody because they don't want to do something your too afraid to do yourself. Don't try to tell me you knew it was safe because you were supervising from across the street. Anyway, glad it turned out okay.
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I wouldn't have fired the inept B-stard over that, I have much better reasons to get rid of him[:D] Although I could never do it, Bill is our comic relief here. Plus he likes to do dangerous things. Some people live life in the fast lane, well Bill lives it in the oncoming lane, all you have to do is give him an excuse to do dangerous things and he jumps all over them. Welding a full tank of fuel, yes, probably not the smartest thing to do when you think about it. But it works. I don't think I would be in to big of a hurry to try let Bill try it again though. I like my ranch right where it is.
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