Pic#18 and #19 shows side-by-side comparison photos of a weld made with the arc-stabilizer coil (left side) versus the weld made with no arc stabilizer (right side).
So where to next?
Firstly, I need better electrical connections - the fastest way to deliver more welding current.
Secondly, I'll keep scrounging for more copper wire - as every foot I can add to the coil will increase the coil inductance and smooth the arc - albeit at the penalty of somewhat reducing the welding current.
Thirdly, I'll keep looking for a source of that magical 'soft' ferrite - as that would really boost coil inductance and help smooth out the arc - without dropping the welding current!
OK folks, I think I have beat this welding with two car batteries to death.
It works - you just need to lug around 20 pounds of a home-made arc-stabilizer coil!
Still, with car two batteries, the stabilizer, some booster cables, a rod holder - BINGO - you have a truly portable 150-amp DC welder.
As for me, I now have a 150 amp pure DC welder that cost me - nothing - but days and days & night and nights of play time!
Hey, maybe I also have an inductor that I can use to smooth the arc of any DC welder - I can just add the coil between the work piece and the ground cable of the welder. Might come in handy should I ever want to push my SP-175T MIG welder to its upper limit.
Hmmm... I wonder how Arc-Stabilizer Coil #2 would work running 36 volts - with 3 car batteries???
Na - who would want a portable 150-250 amp DC welder for cheap?
(I wonder how much current such a 'puppy' would really deliver? ... and I do have those batteries just sitting there.... )