gas tank welding anyone?

dirt head

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well i figured i should try to post here and hope for a little luck.. I have a gas tank off of my big bear chopper that needs some welding. I took it down to a custom cycle shop here in san diego almost 2 weeks ago ,spoke with the owner about the job etc. At first he was like no problemo we can take care of it just leave it here. So now about 2 weeks later I show up and the tank basically was just moved around the shop from -here to there.. I called 1 week after leaving it there just to follow up ( since i didnt hear anything from them) and got an uneasy feeling about the whole thing. it seemed like he wanted to milk me for alot of $$..anyways just glad to have it back. I know some of you are great tig welders on this site and may know of some resources i can try any input would be appreciated, thanks!
 

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Chase 2

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Looks like the fitting was brazed onto the tank, not welded. What part needs welded? Like said an inert atmosphere in the tank will prevent problems.
 

Mike @ pit b

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I had a welding teacher that was given a gas tank to weld, it had been steam cleaned 3 times and purged with argon.
He ended up breaking his welding hood after the tank exploded and sent him flying 20 feet into a wall. I don't know how big the tank was, it really didn't matter to me as I will never weld one up after hearing that.


I would suggest no to do it.
 

dirt head

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Looks like the fitting was brazed onto the tank, not welded. What part needs welded? Like said an inert atmosphere in the tank will prevent problems.

its the trhreaded bung on the rt.side it has a hairline crack halfway around the weld.. i beleive it was tig welded originally, its been 5 years since it was painted , i really cant remember to be honest
 

HardCharger81

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I was alwas told to put dry ice in them, the gas will push out the fumes.

Worked everytime I've welded up a tank.
 

LTL220

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If it's been sitting empty for 2 weeks there are no fumes left. If your still escared (I didn't mean to escare you) fill it with water till its overflowing. Gas (oil) are lighter than water so this will push any petro out. Then weld away!









FYI (I'm typing this from the burn ward) :D
 

loufish

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If it's been sitting empty for 2 weeks there are no fumes left.

...uh...not always...
We were going to weld up an old Suzuki TM tank, ran water thru it for a while, then let it sit for awhile....While welding it had enough fumes to allow a small explosion lifting the tank about 2 ft off the bench, and puffing out the tanks shape...We all laughed, finished the welding and the owner had almost 1/2 gal extra capacity...
 

LTL220

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...uh...not always...
We were going to weld up an old suzuki tm tank, ran water thru it for a while, then let it sit for awhile....while welding it had enough fumes to allow a small explosion lifting the tank about 2 ft off the bench, and puffing out the tanks shape...we all laughed, finished the welding and the owner had almost 1/2 gal extra capacity...


lol! :D
 

Brian Mc

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Fumigate the tank with exhaust fumes for approximately 2 to 4 hours. This is what I have done in the past, it has never let me down or blown me up.
 

5racer

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i used to weld tanks ,aircraft ,boats,all of them some with water ,some with argon .i have had two of them do flame outs not blow but left the table like a jet airplane .after the second one i said screw this there to unpredictable .and for what money was involved was not worth it so i stopped well my dad kept on doing them and i would tell him its only a matter of time pops before you pop one and sure enough boom 40gallon alum take blew, the end cap blew of the tank sheared the regulator of the argon bottle bounced of some walls and stuck half way though our office wall blew all the light bulbs out of the shop and the windows blew the steel end caps off our steel building and sent the tank out the big door about 150 feet,it broke my dads nose ,hand and he cant hear with out hearing aids now .he was lucky that the end cap and baffle blew off in one shot.i wasn't there at the time but was called about it right after, it looked like a bomb went off and with all the blood in the shop i just knew i had just lost my dad.the explosion was so big that it shook brick buildings down the street.and to make matters worst it was 1 day after the Oklahoma bombing we had every state and federal task force there is at our place wanting to know what we did there lol.after going over everything on why it blew we came to the conclusion he made a mistake when you purge with argon its hi volume in and low out there were many vents in tank so he plugged them with duct tape we have done this many times before with no probs but this time when making the the argon vent hole he used a awl to poke threw the tape and when pulled the awl back out the tape re closed .and wallah no vent struck arc and boom .so those that weld tanks and think theres no threat at all don't forget your still human and your day will come no matter how good you think you are .so ask your self is the money really worth it .
 

dirt head

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man i figured there was some reasonable risk to welding a gas tank and by all means i am not trying to go about it on my own.. thats why i took my tank to a custom bike shop that is familiar with this type of job in the first place. yes they were too busy or for whatever reason i was put on the back burner but i guess i should have been more clear- i am hoping that some one on this site can recommend me to somebody, or that is set up and capable of taking this job on themselves??anyone ? I have seen so much awesome, beautifull work and craftsmanship among the threads of this website that i figured i would have a good chance of getting my gas tank welded so i can get back in the wind
 

Superfab

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I've welded many tanks and allways washed them out with Dawn dish soap first till they smelled clean. Then I purge them with argon when welding as insurance and to keep the inside from getting scale on steel tanks. Never had a problem in 30 years of doing it this way.
 

prdracefab

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Fumigate the tank with exhaust fumes for approximately 2 to 4 hours. This is what I have done in the past, it has never let me down or blown me up.

hes right exhaust fumes from your vehicle works great but need only be done for 40 min to an hour just did one thursday on a buggy tank if your local bring it buy pm me for address should only take 5 or ten minuets
 

drsnutz

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hes right exhaust fumes from your vehicle works great but need only be done for 40 min to an hour just did one thursday on a buggy tank if your local bring it buy pm me for address should only take 5 or ten minuets

here's your answer, i was taught the exhaust method some 20 years ago by steve spirkoff at spirit racing in el cajon and have never had a problem. something about burnt exhaust gases that burn up what hydrocarbons are left in the tank. if you can take it to prd.
 
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spi6616

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I used to weld gas tanks many years ago and rather than using (expensive) argon I used (cheap) CO2 and had a very safe record. Utilizing dry ice produces the same results however the pressure in system is not the same. In other words pressure from one end of the tank and a smaller hole out the other after a few minute of purging should do the trick. Some of you chemistry guys out there are saying.... WHAT ABOUT THE OXYGEN molecules??? CO2 is know to work as an inert gas in many applications and does not accelerate burn because of the 1 carbon molecule. Any why you look at it is is still risky!
 
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