2 broken 300-500amp 20-40v dc arc welders

hi everyone i am getting at least one industrial 100% duty cycly broken arc
welder on thursday and am wondering about the parts i can expect to get out
of it. i very briefly looked into the case and there are 3 smaller(1 foot
by 1 foot) presumbly low voltage xfmrs and i think one much larger one but
havn't examined it enough. there are also some very large low voltage caps
and i think a variac but dont know what size variac to expect this whole
thing runs off 3 phase 220v i think it draws around 10-20 kva. also i plan
on rewinding one or more of the xfmrs for HV and would appreciate any
advice from people who have done it before. i have placed an order for 50
.1 uf 3kv caps from mouser at 1.68$ each so i will ahve a cap of around .02
so i am still limited by that as to how big a xfmr i should make. i also
have a 18 turn 1/4" copper tubing pri, 4" , 6" secondaries wound with 24gua
and a 6" coil wound with 28 gua (designed for low power input). so i should
proubably design a xfmr to meet these parameters.
	thanks in advance 
			Chester Lowrey (in warm Hawaii)