Dear all,
I want to make a spot welding machine with a microwave transformer 800 E 120 vac 60 Hz (my house use 120avc 60Hz main power)
To solder 2 pieces of metal (cut from food tin cans) about 0.30 mm thick. Please advise me how many volts and amps out is need
Hope you understand my question and guide me. Thank you very much.

 

... There is some discussion on MOT spot welders here:
MOT spot welders
... For your application, joining a different metal, some experimentation may be necessary.

 

You usually need as lowest turn secondary you can, think of the single turn secondary weller solder gun.
Don't forget to maintain a relatively high electrode pressure!

 

OK, you could use that transformer with a rectifier to charge up a capacitor , and then use the current pulse from the capacitor to do a spot weld. That could work rather well. But the capacitor will need to be rated for at least 1500 volts, which will be a bit expensive.

 

OK, you could use that transformer with a rectifier to charge up a capacitor , and then use the current pulse from the capacitor to do a spot weld. That could work rather well. But the capacitor will need to be rated for at least 1500 volts, which will be a bit expensive.

That describes the capacitor discharge welder, which doesn't require the MOT sized TXFMR.