DIY mobile arc-welding set-ups?

Many would probably agree that, in the long run, it’s hard to get by on a homestead without being equipped to weld.  I’ve got oxy-acetylene for brazing, cutting, and metal bending - and a 180-amp MIG welder (runs on 240v line current) that handles most of what’s needed on my place.

I’ve become interested in having access to more a “mobile” DC arc-welding option, and intrigued by what a DIY guy (should I say ‘person’?) can build from available components & materials.

I came across this article on the Instructables website…  http://www.instructables.com/id/Golfcart--Welder

I’m confident the set-up works okay, but I do question the initial description in the article:  “Here's the simplest welder you can make. It's just a pair of jumper cables and a welding rod.  Oh yeah.  And some batteries to power it.”  Actually, that’s  slightly misleading, as the set-up is based on a golf cart, both as the means to get the unit from place to place and as the means for supplying power to the batteries and hence the impetus moving current through the stinger/ground arc circuit.  Without the cart’s recharging system, the batteries would drain down within a limited usage time.  Around where I live, acquiring even a very used golf cart would put the investment for the wherewithal pretty high.


This old article from Mother Earth News’s classic days (1980) is interesting.  The basic unit was put together from an old rotary lawnmower, an auto alternator, some pulleys and a belt, a 12v deep-cycle battery, some resistors, a diode, and wiring.  Apparently, most components were salvaged (or, as with the lawnmower, just old and out-of-service). The battery is part of the system to smooth the current when the arc is struck and when broken.  The author states that the unit yields a maximum of 50 amps of current available for welding.  The unit is shown and described here, in the article…  http://www.motherearthnews.com/diy/portable-dc-arc-welder-zmaz80ndzraw   Below is the circuitry schematic from the article.

My question & reason for posting is Anybody here know anything about building a mobile battery-based DC welding unit?

I would get one of those small 110V wire feed welder and a portable generator.  

That 12V thing looks jinkey.  If your'e doing structural welds, I wouldn't want to chance those with a homemade welder...