I just wanted to throw something out, maybe it might spark off a discussion about "homebrewing" an arc welder.

Anyhow, I am sure many of you know of (or may have heard about) building an "battery box" style welder, for off-road based welding. I am also sure you have ran across arc welders that used larger AC DELCO alternators coupled with gas engines for welding. A few of you may have even seen welders made from recycled microwave transformers.

However, one design that I recently came across I have not seen anywhere else, and I wonder if it is because it doesn't work, is dangerous, or has simply "faded" from memory...

The best I can figure, it would be considered a "resistive ballast" arc welder.

I ran across it in an article I have in an old "How-to Electronics" or such magazine from the 1940's or 50's. Basically, it consisted of one of the old style "conical" heaters screwed into a ceramic lamp base, with one side of an AC plug wired to one side, the other side of the AC plug went to the "ground", and the other side of the lamp base went to the "stinger". The stinger was made from a hair curling iron, and the whole contraption (minus the ground and stinger lines, of course) was placed into a vented metal enclosure. I think there was probably a switch included as well.

Essentially, you plugged it into normal 110 VAC, and you couldn't blow a fuse/breaker, because the heater would simply heat up as usual, until it was unplugged, or the circuit was broken in whatever way. Now, of course, you only got 15-20 amps worth of welding power, but it would probably be useful for lightweight tack welding jobs. You were supposed to use very small rod with it.

This kind of a project might be a great father/son style or similar project. It would even make a good "tinkering" weekend project. But how would you build it nowadays?

I have only once recently managed to find a conical heater element, and that was on Ebay, and I got outbid. Anyhow, I don't think they are made anymore, or if they are, they are harder to find than hen's teeth, so to speak. So, what to do?

Well, there are tons of other heating elements that could be used, with care and caution - toasters and space heater elements come to mind. Many times these items can be had for cheap to free, from garage sales, thrift stores, and sometimes the trash. A little soldering and craftwork could easily yield a nice little welder.

I would mount the whole thing on a wood base, and wrap the element onto a surplus ceramic line insulator, or something similar (maybe mold a support from concrete/pyrolite/plaster - or a mixture?). Mount the element onto the center of the base. Take a large coffee can or similar and "upend" it onto the base. Cut a hole in the bottom of the can (which is now the "top" of the cover), and mount a 110 VAC muffin cooling fan and grill to keep the element under temp. Poke some holes in the base of the can (the edge next to the wooden base) to allow for the "draft".

Can anyone think of a variation on this style of "arc welder" that would allow for more current, but still remain relatively simple and easy to assemble (ie, doesn't require complex "control" electronics, SCRs, triacs, etc, nor does it require "specialty" transformers)?

-- Andrew L. Ayers (keeper63@cox.NOSPAM.net), May 30, 2002

Answers

I can't respond to your specific query because I don't know enuf about that stuff but since you're looking for a (presumably) smallish welder to do field repairs I remember seeing one in an old Mother Earth News. They did a full write up on it.

It consisted of a rotary lawnmower. The blade was removed and a pulley installed on the shaft. An internally regulated (GM-Delco)car alternator was also installed with the shaft and pulley sticking thru the deck of the mower. Of course a belt was installed to drive the alternator. A battery was mounted to the top of the deck and the welding leads run off the battery. Amperage was whatever the alternator was rated for. GM alternators off squad cars are somewhere around 120 amps.

-- john (natlivent@pcpros.net), May 31, 2002.

Back in the 60's I believe it was mechanics Illustrated Magazine that published plans for this type of welder. A few issues latter they denounced it as being unsafe.

-- Jim Fender (Gfender@carolina.rr.com), August 03, 2003.

I have the November 1965 Popular Science magazine with the plans for building a DC welder out of military surplus alternator and a gas engine.All the parts are available from the Surplus Center catalog.

-- Chuck Bowen (dakotaduece46@yahoo.com), November 16, 2003.