Welding on a fuel tank (jerry can)

I would like to convert a 5 gallon steel jerry can into a fuel tank to hold diesel fuel. To that end, I will need to add three fittings to it (fuel intake with tube almost to the bottom, fuel return, and breather fitting).

Presently this jerry can contains diesel fuel.

The way I want it done is to drill holes in the top of the can for the three aforementioned fittings, and TIG weld them on.

To avoid explosion, my plan is to drain all diesel fuel from the jerry can, and fill it with water almost to the top, so that ony very little space is left between water and where I will drill and weld.

Would that be a basically safe thing to do. thanks

i
Reply to
Ignoramus25468
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Add baking soda to the water. I have brazed a VW fuel tank this way.

I have stick welded a gas tank on a forklift that was part of the frame by filling the tank to the top with gas and catching the overflow from expansion in a pan of floor dry as I welded.

Reply to
RLM

Add baking soda to the water. I have brazed a VW fuel tank this way.

I have stick welded a gas tank on a forklift that was part of the frame by filling the tank to the top with gas and catching the overflow from expansion in a pan of floor dry as I welded.

Reply to
RLM

I think I would avoid finding out. Three things come to mind.

First, you could weld the fittings to the cap. (Run the pick up line diagonally)

Next, you could use gasketed fittings rather than welding them.

Or, buy a new can for the project.

To answer your question I do not think a water purge is a good idea. I think the way to weld a fuel tank is to purge with an inert gas, and keep the tank under a positive pressure with the purge gas while welding. Chunks of dry ice might be viable.

As a matter of first impression, a new can would be cheap enough not to risk a failure of the purge and the resultant explosion.

Reply to
Roger Shoaf

It is not a purge, the jerry can will have water filling it almost to the level of where I will do welding.

i
Reply to
Ignoramus25468

Heh, I had to drill a hole in a motorcycle gas tank to enlarge a breather hole in the collar that went down into the tank a bit to help stop gas from rushing out after a crash (I assume that is what it was for).

Did it with the tank filled to the brim with gas, with a wet rag ready to just plop down onto the filler opening if the drill bit or the brushes ignited the fumes.

Dave

Reply to
XR650L_Dave

Ignoramus25468 fired this volley in news:ZJGdnSZXFOxXIZfWnZ2dnUVZ snipped-for-privacy@giganews.com:

Iggy, fill it half-way full of hot water, add about a 1/4 cup of good liquid detergent, and WASH it out. Then rinse, and see if you still smell fuel. If so, repeat until it's only a hint of a smell.

THEN fill it almost full of water, and leave the cap off while welding, so that if there is a small explosion in that tiny volume, it will vent harmlessly.

I modify acetone and racing fuel drums thus all the time.

LLoyd

Reply to
Lloyd E. Sponenburgh

Lloyd, yes, I agree. I will flush the tank with hot water a couple of times, and then fill it to displace ait prior to welding. With the fill cap off, at worst it will be a little whoosh.

i
Reply to
Ignoramus25468

you'd think it's electro-galvanized wouldn't you? i'd think you're going to have to remove the zinc inside and outside to do the tigging. would soldering work? brazing would be a much hotter process huh? brazing would burn off lots more of the galvanizing. i think if it were me i'd just keep washing it out till there were no vapors.

b.w.

Reply to
William Wixon

you'd think it would be electro-galvanized wouldn't you? i'd imagine you'd have to remove the zinc (closely surrounding the weld area) on the inside and the outside to do the tigging. i think if it were me i'd just keep washing it out till there were no vapors.

b.w.

Reply to
William Wixon

Doesn't anyone solder anymore? Use two big coppers, heated by a torch a few steps away from the tank and above it, then there wil be no source of ignition. Just keep swapping coppers as they cool.

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Since you are planning on TIG welding, we know you have Argon. As it is heavier than air, plug the other holes and fill it from the top, no oxygen, no fire.

I have heard of tanks filled with water still going off, the fumes will still be in any air space, so the preceding two methods are safer.

Reply to
Stupendous Man

I have done this many times.first wash out tank with liwuid gunk degreaser.flush it good with water.but tank on bench.stick airhose in tank low preasure.leave tank sit 5 minutes.leave airhose in while welding.no stangent fumes no explosion.a old mortorcycle mechanic taught me that 50 years ago

Reply to
honestron3232

I did something similar on MC tanks, but used CO2 because its inert and heavier than air.

Reply to
Bob La Londe

filling it with co2 from a fire extinguisher works pretty good.

Reply to
Clare Snyder

That's how I repaired the oilpan on a '65? Riviera ---

Reply to
Clare Snyder

Argon or CO2 either one , if you happen to have welding shield gasses on hand . Big plus is that it leaves the extinguisher usable for it's intended purpose .

Reply to
Terry Coombs

Disn't have sheilding gas - so I just sent the apprentice out to the safety supply to borrow a 5 pounder

Reply to
Clare Snyder

Would engine exhaust work?

Reply to
Jim Wilkins

snipped-for-privacy@gmail.com on Sat, 4 Jan 2020 14:50:31 -0800 (PST) typed in rec.crafts.metalworking the following:

That will work.

So will filling it completely with the fluid of your choice. Water is good, but a boss of mine brazed up the leak in the gas tank, on the car, "$10 if you watch, double if you don't." Yes, and even he admits "Not the brightest of ideas. but I did make twenty bucks."

Reply to
pyotr filipivich

I worked in a building that sold ice and dry ice. The got orders for a couple of hundred pounds of dry ice on occasion, from people removing fuel tanks from gas stations.

Mikek

Reply to
amdx

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