3 car battery arc welding.

[Leatherneck]

Cool vid.

[MarioVelotta]

In a pinch I guess

[Ol'fogasaurus]

I seem to remember when I was a kid of being told that they use to weld with Model T timers also.

Lee

[Stray Catalyst]

I've seen two 4x4's used to weld a broken frame in the field, with a couple of sets of jumper cables as the only equipment needed. It worked out to be a not-particularly-controllable 24VDC arc welder - but it was enough to get a frame-cracked car out of the field.

[perrib]

It works and like stated you don't have to walk out. Or if you have more disposable income: http://www.readywelder.com/

[Stray Catalyst]

Looks neat - but $700 for something you're only going to use in a strange emergency, as opposed to something you can cobble together with two other cars, three sets of jumper cables, a few welding rods, and a mask? As most off-roaders already have a good set of jumper cables, you can weld with a couple of friends and the equipment you already have, as opposed to spending several hundred dollars for a tool you'd use less than once a year.

[fusername]

Cool stuff. I have seen a welder that you hook up a running car alt to. I think anything over 100 amps it said. Was a bona fide full function arc and mig/spool welder. Seemed really cool alternative to a generator/welder combo for someone who does a lot of field work. As for three batteries, I promise ill end out needing that at some point

[GA_Boy]

That is cool, I enjoyed the vid. Along the same lines using a car battery I once saw my older brother (1912-1977) solder a hole in a radiator using a 6 volt battery and a sharpened carbon center rod from a D-cell flashlight battery and either lead or solder. This was around 1949 and I was too young to remember details.
I think the same principle (sp) was used in carbon arc lights.
Marvin

[Piledriver]

I am actually strongly considering building a riding welder... I have an old Scotts 18HP twin rider, it's mostly shot but the motor is beautiful Briggs twin with oil cooler/alternator etc.

I picked up a nice new spool gun on fleabay, and have alr3ady adapted it to my existing MIG/arc setup with a matching Binzel plug (the cheap welders internal feeder was junk when new...)

There's some good info on on http://diy-welder.com/buildit.shtml but the guy no longer sells the control boards he made, nor seems to respond to emails.

Basically I want to be able to MIG or TIG, pulsed would be nice, and 150A at 100% duty cycle is nothing to sneeze at.

OTOH it's nice to be able to flip a switch and go.

I'd probably be further along if it wasn't 107 degrees out and welding is prohibited anyway due to risk of setting neighborhood on fire...