HID ballast for a spot welder

[challenger]

I'd like input on using a large ballast from a HID lighting system as the power source for a spot welder. The one I came across is 20 lbs and 1000 watts. I'm confused about the multiple input taps and the huge size of the secondary. Any help is appreciated.

[SLK001]

What you have will give you high voltage at low current. What you need is low voltage at high current. Something along the line of a microwave oven transformer rewound for the high current/low voltage output is what you want.

[challenger]

I did plan on rewinding this large transformer secondary as is done with the MOT.

[SLK001]

I did plan on rewinding this large transformer secondary as is done with the MOT.

Then a 1000 watt transformer should be able to do what you want.

[Bob Engelhardt]

Then a 1000 watt transformer should be able to do what you want.

When I made my spot welder, I found that a 1200w MOT wasn't enough power and used 2 of them to get enough.

The OP's 20lb, 1000w doesn't seem right. A 1200w MOT is only 5lb or so. The MOT's duty cycle is way less than an HID's ballast, but still.

[J Tiers]

HID ballasts have extra steel for a partial magnetic shunt, etc. They are not like a standard choke coil.

[reggie_obe]

If you own a good brand MIG welder, they do make an add-on for a spot welder.
That was true for my Hobart and I don't mean some Eastwood product.