Welding with a Flux Core Arc Welder

"Once you have a garage, you have to have a buzz-box," says my cousin. What's a buzz-box? It's an arc welder.

Warning: Don't try this at home! Arc welding works by running high electric current through bare metal. It requires special clothing, face shield, insulated work area.

September 6, 2008. I have never welded anything before but why let that stop me? Oh, see the warning above! I want to build an electric car, so I need to be able to weld. I found this Lincoln on Craig's List:

This is a 110 volt 135 amp welder, claims to be able to weld 5/16" steel. I have plenty of 20 amp outlets in the garage making this portable. It came with a 10 pound spool of flux core wire so I can get plenty of practice.

Here is a picture showing how to set up a weld:

The "torch" has a thin hollow wire running through it. The wire contains flux which vaporizes when heated thus shielding the weld with gas so that the hot iron doesn't oxidize in the air. When the switch is pushed, the wire feeds out at a speed determined by a dial on the front panel. At the same time, the wire becomes electrically "hot". The copper clamp provides a path to complete the circuit so an arc forms at the wire tip and melts the wire. The heat melts the iron piece thereby fusing it all together.

September 8. One of my goals is to make battery cages out of 1/8" thick angle iron, so I will practice on 1/8" flat iron scrap. I will use the welder as a flux core arc welder (FCAW). It can be set up as a MIG (metal inert gas) welder but that requires a gas bottle and regulator. A MIG welder will make cleaner welds but I am OK with FCAW for now. Here is my first weld:

Not so good as it doesn't penetrate into the gap between the pieces. It broke easily. I did more research, found I should make a groove between the pieces.

September 11. Here is a weld after several more attempts:

Not great looking, but very strong. Strong enough for battery cages.

September 13. I got some scrap iron from Fazzio's. Here are a couple of pieces of 3/16" angle. I cleaned the ends up with grinder and wire brush:

The pieces are firmly held at 90 degrees in this convenient clamp:

Ugly weld, cleaned up a little with an air grinder. The vertical is particularly bad:

I ran a bead along the back to make it stronger:

September 14. I try welding thinner steel:

Too much heat will cause burn-through so I tried the lowest setting first. The result is "too cold." The metal doesn't look like it got hot enough to fuse with the iron wire. More practice needed; "just right" tells me I can find the right conditions to weld this thin plate.

September 16. I tried thin steel again but with a back-and-forth motion suggested by a friend:

Too hot and lots of spatter. Try again:

Mostly good. There was a gap on the left that I went back and tried to fill. Blobs. I think the right 2/3rds looks good.

September 20. More practice, this time on 1/8" angle iron:

Nice fit. I put these pieces in a plastic miter box and cut them with a hacksaw:

Ugly weld but it will hold:

I welded the other side for more practice. Easier access and probably sufficient to do just this side:

Setting up takes most of the time so I got some clamps like this one from Harbor Freight:


October 9. I put up two more sheets of OSB, built another workbench:

October 11. A dedicated welder's station:

October 13. With wire brush and storage for stock underneath: angle iron and sheet steel:

December 2010. Welding is very practical and a lot of fun. I have used the welder to repair exhaust systems, build battery boxes for my electric car:

...build a motor mount for my electric car:

...fix the mower, mount a hose reel for the air compressor, build a tripod:

The list is endless since I constantly find new things to weld.