motorcycle gas tank welding -advice needed

I have an old gas tank off of a motorcycle that needs a mounting tab tacked on to it. When I emptied the tank, the gas was real old and smelled like
varnish so i flushed the tank with acetone (rusty in there), then rinsed it out with soapy water several times. I dont think it would explode because of the age of the fuel that was in it and it was thoroughly rinsed but i'm not a big fan of blowing my fingers off my body so i'm a bit relunctant to mig this thing. A friend suggested to go outside with the cap off and stick a propane torch in the opening and see if it flashes. If it doesn't, it most likely wont explode. Any comments before I muster up enough nerve to tack this tank.
thanks in advance, walt
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Walt,
You have taken some good steps to get rid of most of the fumes. Buy a nice chunk of dry ice and put it in the tank and LIGHTLY cap it. (Saran Wrap the gas cap flange). This will keep the CO2 in the tank but let any pressure escape if necessary.
Done this on car gas tanks and no problems.
I don't thing trying to make it explode by putting a torch in it is a good idea.
Bart D. Hull snipped-for-privacy@inficad.com Tempe, Arizona
Check http://www.inficad.com/~bdhull/engine.html for my Subaru Engine Conversion Check http://www.inficad.com/~bdhull/fuselage.html for Tango II I'm building.
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wallster wrote:

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tacked
it
of
not
all done fellas! I purged the tank with argon from my tig and tacked it with the mig... no boom. thanks, walt

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Just fill the tank up with water. Close the cap and vent tube. Turn the tank over so that the area that you are going to weld is located at the small air space left in the tank. I have done this with Oxy-acetylene and occasionally I would get a little burp at the crack or opening I was repairing. There wasn't enough space for any gas residue to have any power. Randy

tacked
it
of
not
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I did the same thing. I got a hole in my tank from something that got kicked up off the road. I filled the tank with water and as much as I could leaving only a small air pocket. I was going to braze weld it shut with my propane & oxy torches. I had at least 90 % full of water. When I put the torch to it the tank still had enough vapor in it to cause it to give a big burp. Water sprayed me all over from the fill hose. It scared the snot out of me! I wasn't sure if it was the water from the tank, or if I pissed my pants!
Randy Hansen SC Glass Tech Scam Diego, Comi-fornia

because
mig
a
most
tack
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like
rinsed
i'm
stick
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I have done quite a few with co2 or argon, and no embarrasing burp either. Do yourself a favor while it's cleaned out, and line it with Red-Kote (my favorite), Kreem, or some other "fuel tank sloshing compound".
--
Paul Calman, Hathaway Pines, California




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If you put the exhaust from any engine into it and weld with the engine running you will be ok. The exhaust will not burn, no oxygen. It will stop the fumes from exploding the same way dry ice does. - no oxygen. This works great, and no need to find a supply of dry ice.

to
it
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Reminds me of the old joke. A parachutist jumped out of the plane, counted 5 and pulled his rip cord. Very little happened. Oh *** he thought. Never mind, dump that canopy and deploy the reserve. Pulled the second rip cord and nothing happened. He is now plummeting earthwards at a fair rate when he sees his pal flying upwards at a similar rate. "Know anything about parachutes?" he shouts. "No" came the reply, "can you weld gas tanks?" Apologies to all who have heard this before.
John

tab
smelled
but
relunctant
to
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Randy H. wrote:

Haahahaha. You just made me spit coffee!
rvb
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most
I, for one, would be interested in understanding why a gasoline vapor explosion caused by a propane torch is, somehow, of lesser energy - thus safer - than a gasoline vapor explosion caused by any other source of ignition......
--
Bob Paulin - R.A.C.E.
Race Car Chassis Analysis & Setup Services
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vaguely proposed a theory ......and in reply I say!:
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I believe the torch is meant to be lit before application. <G>
I also reckon the "friend" who suggested this should be invited to try it themselves.

***************************************************** It's not the milk and honey we hate. It's having it rammed down our throats.
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I believe that would be like a comparison of 110v. and 220v. One will kill you. The other will only blow off a few fingers and knock you unconscious for a while.
Or was that vice versa?
It's been so long since the explosion, I don't remember.
Is the phone ringing?
bye
.......................
steve ........................ ;-)
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SteveB wrote:

220V merely tickles.....its what you're used to that matters...
Steve
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thus
kill
unconscious
Tickles, my ass. Try it hot and sweaty lying on your belly and brushing a 3 phase feeder. With very little room to maneuver away from it.
Garrett Fulton
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wrote:

Brrrrrr...the memories of something similar still haunt me....
Gunner

"There is no difference between communism and socialism, except in the means of achieving the same ultimate end: communism proposes to enslave men by force, socialism - by vote. It is merely the difference between murder and suicide." - Ayn Rand, from "Foreign Policy Drains U.S. of Main Weapons"
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wrote:

I just got bit pretty good week before last - 277V from the base of my left index finger to one of my forearms laying on the rim of the steel access hatch in grounded steel lath ceiling falsework... Wa-Ha-Ha-Hoooiee!!! Was repeating George Carlin's "Seven Dirty Words" routine for 30 seconds ;-) and shaking my arm for a half hour...
Compared to that, 120V is nothing but a strong tickle. The little (1/8" x 3/8") 2nd degree burn where the wire touched at the edge of my palm (almost on my thumb web) made a dry blister and is healing up nicely.
G--D---ed retail store in an old office building, with the 277V panel for those lights locked up in another office's utility closet. Which made it far easier to pull the wirenut in the ceiling to kill the fixtures we were replacing two at a time...
Moral: Copper wire makes a decent spring and can jump sideways to bite you when you take the wirenut off.
--<< Bruce >>--
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
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gfulton wrote:

Depends where you're pointing....
Try it hot and sweaty lying on your belly and brushing a 3

phase-phase you're up to 415volts, that DOES hurt.
Steve
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Yeah. And it was 400 cycle too.
Garrett
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On Sun, 15 Aug 2004 20:14:51 +0100, Steve Taylor
Worst I've seen was 50V - telephone exchange busbars. They'd deliver a squiggaamp and not break a sweat. At least 230V usually has some sort of fuse somewhere.
Lately I've been zapping myself with 12V - the electrolytic derust tank, because I'm still to stupid to always switch it off before going near it. It's "only 12V", but across two hands that are wet with salty water, you sure feel it.
--
Smert' spamionam

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