Questions on AC welding machine

[Mutt]

So I see a alot of videos of people making good spot welders outta microwave transformers. I took a microwave apart today (Panasonic) and it had the most ridiculously cheap transformer I have ever seen. Not even sure how it even worked. It was mostly plastic and the fewest winding of I have ever seen. So my question is this

Since that AC transformer just loses it secondary windings and some 2/0 welding cable is just double wrapped it in it's place and the rest of the machine just hobbled together from scrap laying around, I got to thinking. Why wouldnt it be possible to just install a couple of tapered copper mig welding tips into the electrode and ground holders of a AC welding machine and just use the welding machine for the current? I mean, you could make some tongs outta steel and screw the tips into it for better control, but will this work, or will the welder short circuit or something?

 

[ericc]

For a spot welder, you need higher current and lower voltage. If that microwave oven transformer did not weigh at least several pounds and have a few thousand turns of thin wire on it, with the secondary directly switched in from the mains, it is probably an inverter microwave, and not all that easy to make a spot welder out of.