Welding on Gas Tank

[Steved]

Sorry. I call bullsh*t that the tank was welded.

You can't cheat physics, the flash point of the vapor is WAY less than the fusion temp of metal. If there was fusion there was an explosion/fire.

If anyone else reads this, do NOT ATTEMPT TO WELD ON GAS TANKS, this guy is some joker and will get someone killed.

If it is a joke, he is an A**HOLE for causing people concern for no reason. I think that in general the people on this site want everyone to weld well and weld safe.

[Sberry]

I have to confess,, I have done it. A gasoline tank on an old bulldozer. It had a pinhole or crack, I filled it full above the crack and weldd it up. No air behind the crack, no explosion. Done lots of diesel tanks. Would I tell someone else to do it,, likely not, would I endorse it here, not, what do I think of a thread that starts with,, I have a 300A stick machine and a 251 and I am in a hurry to go sit on the beach and I am going to weld on this sheetmetal tank in the van and I dont have time to have it proffessionally repaired. It screams that I am NOT a pro and am careless right up front. Even the Miller people dont jump in on this one. It says there is a lawyer not far behind.

[AV8OR]

A joke:

Question: Do you know what the last four words someone from ________ (fill in the bank) says?

Answer: “Hey y’all watch this!”

[AV8OR]

Story One:

I remember years ago we had a Firefighter come to class for fire safety week. He took a clear beaker of gasoline and stuck a device in it that jumped a spark between the two poles in the gasoline. No Kaaaaabooooooom! Next he jumped a spark above the gasoline and we had ignition!!!! Morale of the story is gasoline isn’t flammable it is the vapors.

Story Two:

The backyard neighbor kids were helping dad start the barbeque cooker. The Gulf Light Lighter Fluid didn’t get the coals going so one of the kids got a coffee can of gasoline to toss on the coals. Some of the coals were glowing underneath from the first try and Kaaaaaaboooooom!

I can close my eyes and still see the scars on that kid’s face and his chest today thirty-five years later. Morale of the story is don’t F&%K with gasoline!!!!

[glockdoc]

Back when I worked in a power generating plant, workers would routinely weld on the huge fuel oil tanks (yes, containing oil). Don't believe they purged the tanks with an inert gas-can't remember. Also, fuel oil isn't as flammable as gasoline, you can actually put out a match trying to ignite it. as stated before it's the vapors with the correct fuel/oxygen ratio that causes the problems. In theory, no oxygen, no kaboom but you won't catch me trying this. I can't think of a more horrible way to die than burning to death.

[JOHN1]

Rabbit

Not trying to be offensive "Rabbit" but we get a lot of people that
know absolutely zip about welding on this forum> I know enough to ask.
My opinion is, if you have to suggest idiot procedures as this, don't do it here.

Again, this is not my forum, I am only a fortunate student.

John

[orgalmeister]

White Rabbit... hmmmm... "one pill makes you stronger and one pill makes you small" kind of explains alot.

DO NOT TRY THIS AT HOME KIDDIES!!!

[kdahm]

I wouldn't say it's smart

But it also isn't in the 100% certain death category.

More like the 95% the first time, and 99.9% for repeated attempts.

Gasoline vapors are explosive. Other VOC vapors are explosive. for each type of vapor, there is a minimum vapor content that is explosive and a maximum explosive vapor content. The minimum is controlled by the amount of vapor required to sustain the burning flame front, and the maximum by the least amount of oxygen required to sustain the flame front. When either paarameter is exceeded, any gas that sparks cannot spread because the flame front cannot travel fast enough to continously ignite the vapors.

A partial list of flammable organics, in the order of most to least explosive, is:
ethanol/methanol
white gas
mineral spirits
gasoline (higher octane - easier flammability)
diesel
motor oil/cooking oil
fuel oil
Navy bunker fuel
asphalt

Notice the trend. If you are really curious, the MSDS for each substance has the concentrations required. For example, mineral spirits are 1.3% for the lower limit and 9.8% for the upper (approximate) and an ignition temperature of 660 F. Strangely enough, the vapor of a partially full tank usually falls inside the explosive limits for many compounds.

Should someone choose to weld on a tank containing one of the more volatile compounds like gasoline

[LAWYER NOTE: THIS IS NOT RECOMMENDED AND, IMHO, SHOULD NOT BE ATTEMPTED BY ANYONE WHO DOESN'T KNOW EXACTLY WHAT THEY ARE DOING AND THE PROPERTIES OF THE COMPOUND IN QUESTION AND HAS PAID UP LIFE INSURANCE AND AN EXTREMELY LARGE CLEAR ZONE WHERE RESCUERS CAN PICK UP THE BODY PARTS]

the less dangerous method would be to fill the tank completely to eliminate any vapor pockets. Then the major concern would be exceeding the autoignition temperature while welding, at which point the liquid will start burning. Don't forget to do this in an extremely well ventilated area so that fual vapor pockets around the tank from filling it can dissipate or be diluted.

Fuel oil and Navy bunker fuels are easier, because the flammability is lower and the stuff volatizes less.

No one has any business doing anything remotely similar to this in a residential neighborhood, near anyone else who will be injured when something blows up, or in the vicinity of someone else's property which may be damaged by the explosion.

If someone elects to do this on their own property, to their own equipment, not near (~1/4 to 1/2 mile) from someone else's property, after sending their wife and kids to Grandma's or shopping, then I would see it as natural selection in action. Please give the local fire department a call to warn them so they don't have to interrupt dinner to answer the alarm. A last will and testament is also a good idea.

Yes, someone can get away with it once. They can get away with it several times. If someone is routinely driving around lowered railroad crossing arms, they will eventually get hit by a train.

As pilots put it, is a delay of several hours, or even days, worth the rest of your life?

Karl

[tackit]

I would have used the vacation money to instead buy a new fuel tank go on vacation at a later date.

[fun4now]

jokers

it seems we have picked up a joker that keeps changing name to play.
seemed to be a lot of foolish stuf ever sence the naked welder and his foolish ???'s. perhaps he just has to much time to think of anything better to do.
naked welder, rabits and pokie bears??????
whers the oh my ?

[MACH4]

Have I welded on fuel tanks,... yes I have. Gasoline,...... no way!!
I will weld on diesel tanks and I purge them with CO2 for at least 30 min. before I even use the gas monitor to check the LEL.I also charge an additional fee for this service,given to the cust. before the job is started.For a hobby welder to weld on a gas tank, please sign your DONOR card first!!!!!!!!!!
Mike
MACH4

[gnewby]

There was quite a discusion on the Hobart site last fall about the welding on fuel tanks. In Sept. of this last year I had posted a story about an incident that happened not too far away from here where a welder mechanic was trying to repair a leak on a diesel fuel tank. It exploded killing the one man that was 47 years old. He did not die right away though he died a few days later. The best advice I could give to anyone wanting to make repairs on a fuel tank if they are asking for advice on how to then the best thing to tell them is not to. Either replace the tank or take it to someone that is a proffesional at it.

[Steved]

I hate to keep pushing this but....

I repaired my leaking diesel fuel tank with JB Weld.

I made sure that the area was clean and abraded for good adhesion.

I applied a liberal smear of JB Weld and sandwiched the glue with another piece of metal and held that second piece of metal with a 'wrap around' strap.

It has been holding strong for 7+ years. In this case there is NO chance of explosion.

Total cost:- about $10.