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. I happened to have some nice juicy batteries in the form of a Golf Cart.
Here's me welding a trailer hitch with 1/8" 6011 rods. Welding current peaks at around 140-150 amps with these rods and around 120 amps with 3/32 6013 rods according to a Fluke 1010 clamp probe.
Oops! Almost forgot a warning. DON"T ELECTOCUTE, BURN, OR BLIND YOURSELF. DON'T BREATHE THE FUMES OR DETONATE YOUR BATTERIES. That said, read the specs for your battery. Big ones are designed to produce enough current for welding. Don't let the nay-sayers keep you from trying it. Check your batteries and don't overheat them. Lead-acid batteries can go into a thermal-runaway self-discharge mode.
Here's the stuff. The jumper cables were $12 from Harbor Freight. The strip of bicycle innertube is optional, to wrap the end of an alligator clip and make it grip harder. If you're feeling fancy you can replace one of your alligator clips with an electrode holder. This nice one was made in India and cost $7 from Harbor Freight. The welding rods I tried are 3/32" 6013 and 1/8" 6011, 5lbs for $6 or so. Available in Africa, S.America, anywhere.
You'll also want to wear gloves, and a welding helmet, $16 from Northern Tool