Homebuilt Arc Welder

   This time I am going to try the art of arc welding using the batteries available. Most dc welding work at around 40 volts, and a general purpose electrode of 1/8” will need about 120 amps for good penetration of weld. Thirty six(36) volts is available from three automotive batteries connected in series. This simple diagram shows how to hook it up:

   to metal plate <--- +battery- +battery- +battery- ---> to welding rod

An optional arc stabilizer inductor in series with the rod, made from scavenged microwave oven. Chop out the secondary and wind 20 turns of 10-guage wire. Leave the primary intact, it doesn't affect the function here. An inductor gives the current a momentum to blast through bits of flux and rust that get in the way. This makes the arc sputters a lot less, welding is easier, and the welds are better.

Photos of the project:

 First I built a safe box to hold the batteries. Then, I created a set of series-parallel batteries wired for 36 volts. Noticed I used 12 gauge wires to wired the batteries and soldered them to the posts. These are just the available parts I had at that time.

 These are cheap, sla batteries I salvaged from old uninterriptible power supplies from work. You can also find these in electric scooters,  7 amp hour, 12 volts.

Due to small amperage capacity, I intended to use this 1/16 inch electrode, one of the smallest electrodes available on the market..

My complete kit with set of gloves, electrode holder made from pvc pipe, an old goggle purchased from the nearby thrift shop, alligator clips. ready for a test.