Clare Snyder on Sun, 05 Jan 2020 20:45:28 -0500
typed in rec.crafts.metalworking the following:
On Sun, 5 Jan 2020 17:16:54 -0800 (PST), Michael Terrell
wrote:

On Sunday, January 5, 2020 at 12:16:41 PM UTC-5, pyotr filipivich wrote:
on Sat, 4 Jan 2020 14:50:31 -0800 (PST) typed
in rec.crafts.metalworking the following:
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
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."

I tried the water method once, on a 30 gallon tank from a '73 Chevy stepvan. I rinsed it out, then filled it to the neck with water. I didn't even get the flame to the tank when it jumped two feet in the air, spun around a few times and swelled up enough to uncurl some of the crimped seams. It had a seven inch crack when I took it out of the truck, but Neither my neighbor or I expected areas that were eight inches under water to uncurl. GM's supplier was on strike, and had been for months. The junkyards had been picked bare of every usable tank for repair jobs. I lucked out and called a yard and was told, You're in luck, we just hauled in a truck a few minutes ago. $50, if you remove it. I was shocked that they used a forklift to tip the truck over, but I had the tank I needed.
A friend in highschool (back in '69) had a leak in the tank of his
'55 Fairlane. He drained it. left it sit overnight, then filled it
with water and started welding it. Within seconds he was on his back,
soaking wet with the tank across the driveway.

I've heard of similar incidents. A motorcycle tank flying across
the shop.

Ask Nels about the issues involved in repairing an old fashioned
acetylene generator. The kind where you put the basket of calcium
carbide in the water and collected the gas as it bubbled off.


--
pyotr filipivich
"With Age comes Wisdom. Although far too often, Age travels alone."