Both electrolytic and film capacitors are good candidates for welding machines, Kendeil suggest you to look up at K03, K04, K05, K06, K11 in electrolytic families and K36 & K37 series that are film capacitors.
Pease note from our catalouge that we have a part number reserved digit (“W” in 13th position) assigned to charge/discharge applications, this char remark special capacitors designed on purpose to sustain heavy discharge stress.
Don’t hesitate to contact our technical department asking further information.