1. Welding Rectifier contains a Transformer and the Rectifier.
2. Transformer Filament wounded coil is made of Copper and the rectifier outer casing may contain some copper.
3. Why do you require the weight of copper in Welding Rectifier. Are you looking at the re-sale value.
4. Considering the welding cables made of copper I suppose the copper weight in Rectifier is less.
5. Moreover welding machines of Rectifier type have a huge Fan which runs continuously to cool the machine and the electric power charges are more
6. Nowadays Welding machine (inverter type) offers good portability, Power savings and high Duty cycle.
Thanks & Regards
J.Gerald Jayakumar