Drilling and brazing a fuel tank

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You two gave the exact example of "B/S and scare talk" that I was referring to.

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Reply to
Ignoramus15459
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I agree with every sentence that you wrote.

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Reply to
Ignoramus15459

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Yes, they were all about tanks full of gasoline when they exploded.

No, but like I said, they probably did not observe the precautions.

I will do just that and will video tape it too

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Reply to
Ignoramus15459

I had to solder a couple holes in my little Gibson tractor tank. It holds about 1/2 gallon. The tank has been filled with gas for over 50 years. I washed it out with acetone, then soap and water. After drying it a few days I started to heat the tank to solder it. I saw what looked like maybe a little steam coming out of the filler. When I waved the flame at it it caught fire for a sec. No explosion though. So I think that all the years of soaking in gas left some varnish inside that gasified from the heat. Eric

Reply to
etpm

I've heard of putting dry ice into the tank; it condenses the hydrocarbons and continually purges the oxygen.

Reply to
whit3rd

Ig, the only part of all this that escapes most folks is (as was mentioned in an earlier response) the possibility of welding gasses collecting in the tank and igniting. To that end, it's still worthwhile to 'stuff' the tank with inert gas, water, whatever, leaving only the spot you want to weld free of heat-absorbing substances.

In your case, if you drill the hole, and make sure your fitting which you wish to braze on is a tight fit, you don't have the potential that would exist if you were flame cutting or brazing shut holes.

LLoyd

Reply to
Lloyd E. Sponenburgh

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Like I said, blow yourself up. I had a 30 gallon tank from a '73 Chevy Step Van blow up on me. It had been empty for over two years. It was full of water, but it jumped five feet in the air and sprayed hot water all over me and a neighbor. It peeled most of the crimped seam apart, and destroyed the tank

Reply to
Michael A. Terrell

"Michael A. Terrell" fired this volley in news:weednTOrEphRMIHTnZ2dnUVZ snipped-for-privacy@earthlink.com:

Then, Michael, it wasn't gasoline fumes, it was welding gasses -- or....

if it was "full of water", how, exactly, did you get a volume of gas in there to explode? Could it have been steam pressure, which you inadvertently caused by trying to cut or weld on a part immersed in water?

LLoyd

Reply to
Lloyd E. Sponenburgh

It was on the neck. Just a few inches of metal that wasn't under water. It turned out the inside of the tank was quite rusty, which wasn't visible before it blew. I talked to a couple people who repaired tanks before I tried to repair it, and was assured that nothing could go wrong. They just stood there and scratched their heads after they saw the results. This was in a steel town, where professional welders and machine shops were thick as thieves.

Reply to
Michael A. Terrell

"Michael A. Terrell" fired this volley in news:04WdncZQwPpQX4HTnZ2dnUVZ snipped-for-privacy@earthlink.com:

Well... "sitting on empty" and "empty, and open to the air" for two years are two different things.

I assume (unless welding gasses were the culprit) that there had not been adequate ventilation of the tank.

I've modified numerous "pulled from service" gasoline and propane tanks (of course, emptied, dried, purged, and filled with inert stuff before work), and not had any even _minor_ malfunctions. And usually, all that folderol takes longer than the modifications do.

I deal with a surprisingly high-tech welding/cutting shop in our little town of 2000 that welds repairs on RV gas tanks as a regular part of their business, and they don't have those problems, either.

If it's gasses that are your problem, a _slightly_ oxidizing flame is your friend -- no free fuel, either in the form of gas or air-suspended particulate carbon, gets into the tank by accident.

As part of my practice on propane tanks, I also wash out the mercaptan, which _can_ form an explosive mixture. (household lye converts it to other stuff which can be washed out with water)

LLoyd

Reply to
Lloyd E. Sponenburgh

Empty, with no gas cap for over two years. also, there was a seven inch long stress crack in the bottom that would leak, until there was less than a gallon in the tank over a weekend. That was why the truck sat unused for over four years, and a little over two with no gas cap. I took the locking cap for another truck I owned.

The only thing available to work with was a cheap SolidOx torch, with a small bottle of propane.

Reply to
Michael A. Terrell

We covered such in firefighting class when I worked on a pipeline. You use a different tactic on BLEVE's:

a) Recognize BLEVE b) $^%&%$& RUN ....

We welded tanks/pipelines all the time.

1) Jethero shoots a hole in same. 2) Pound in rubber plug. 3) Let dry {~week} 4) Ensure either good line rate, or sufficent tank fill above weld. [~2 ft comes to mind; less if Diesel than gas.] 5) Lay patch atop plug {can't recall size but say 8" dia.] 6) Weld in place.

Of course, these were slightly larger than the average car's tank; say 60' diameter and 40' tall. And there was NO problem welding to a wall of say 0.375" thick.

Reply to
David Lesher

Exactly.

The tank may have had little usable fuel, but was closed and trapped the remainder and the fumes.

In my case, the tank is dry, the inlet is open, and I turned the tank over so that it sits outside, under the sun, with the open inlet pointing down.

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Reply to
Ignoramus15459

I'd love to read about your explosion in the paper and all, but vapors are exactly what you need to be worried about, they're what explodes, not the liquid itself.

Reply to
Cydrome Leader

"Josepi" on Mon, 11 Jul 2011 18:50:26 -0400 typed in rec.crafts.metalworking the following:

I heard of a gas tank leak brazed while on the car. But the guy a) did it on a bet, and b) filled the tank right up to the brim of the fill spout. Gasoline (liquid) is flammable, but gasoline (vapors) is vigorously so, almost explosively so. Won the bet (doubled because the owner didn't stand next to him in the shop).

Drying/Baking in the summer sun probably is best. Purging with Argon (or other inert gas) would also not be a bad idea. Waving a torch over the fuel intake might also work. Just "be careful", I've heard (from the guy who did it) of the resulting burn off adding a gallon capacity to the car's tank (after he beat the thing back closer to factory shape.).

After a few days in the summer sun - it might be "perfectly safe". Note "might be" - I'd have to see it personally to say "looks safe to me, you go ahead and try it." B-) But purge it with compressed air a good bit before starting is not a bad idea.

tschus pyotr

Reply to
pyotr filipivich

Gunner Asch on Mon, 11 Jul 2011 21:52:10 -0700 typed in rec.crafts.metalworking the following:

Paul's story was of coming back into the shop, just as the new kid put the torch to a motorcycle gas tank, which he had flushed with water (only). Foomp! Gas tank takes off across the shop! Kid standing there with a completely stunned "could have put an apple in it" look.

tschus, pyotr

Reply to
pyotr filipivich

Cross-Slide on Mon, 11 Jul 2011 16:04:15 -0700 (PDT) typed in rec.crafts.metalworking the following:

Ayup. Boss man won $20 dollars that way, in his auto shop.

Reply to
pyotr filipivich

Here's the video

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Reply to
Ignoramus23641

You're quite the egomaniac.. it sounded as though there was a child standing nearby, who could've been injured and/or disfigured if you had been wrong, or if the torch had malfunctioned.

I've had several types of torches nearly go out and suddenly relight at full force when the tip is near a closed pocket or in a corner and then withdrawn..

pathetic

Reply to
Wild_Bill

Hint: the video was not the first time I tried it.

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Reply to
Ignoramus27403

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