Is a microwave oven transformer welder any good? (plus a softstart circuit)

I have upgraded the cooling (burned a winding once) and added a softstart circuit (NTC resistor based). No more blown circuit breakers!

[garymiller]

i read in an old popular science book about how to build an arc welder with variable voltage and current using a "reactor" made from a large coil wound on a square tube with an adjustable iron core (it slid in and out of the tube via rope and hand crank w/lock)... cant remember how it was wired but i think the voltages were fixed on a hand wound multi tapped transformer... voltage selection was with a jumper wire on a control panel lol... was cool...

[mattes]

When the slag comes loose by itself, that's how you detect a good welding seam. It looks like yours wasn't hot enough. Try a thinner elektrode, at the same steel thickness!

[JamesThompson-xlyu]

Although this works, everyone wires the secondary wrong.  Best is to use small gauge wire like 14 gauge stranded of multiple wires to fill the full cavity with wire that is grouped as parallel and total of 2 to 4 turns.  IE 20 parallel wires together and long enough for 2 turns.  The idea is to not leave spaces in the secondary cavity so all magnetic flux is coupled from the primary.  Hope this helps others.

[Bruce_Wayne]

I want to arc-weld brass-to-brass using that device. Will it work?

[josephsmithe]

Nice experiment. Nothing that will replace my trusty everlast 140A welder but a good project for kicks!

[Centar]

I really like that bench/fume hood idea....

[RadMan]

You're welding next to a roll of paper towels. OSHA would have a heart attack

[camerondavis]

Hi im picking up a to mot tomorrow and i was wonder if you can give me some brief instructions on how to do this and what can i do to make it safe this will be my first time ever doing this.

[rwbimbie]

Can you do a vid to wind a welding transformer
from a length of Rebar with 14ga & 8ga diy store wire.
I am having a hard time in my area with these vids telling me to "just" find a free curb trash microwave to gut.

[Altcapball]

If you mess up the primary, can you wind one too?

[nunofontainhas]

What wire did you use on the transformers?

[chrispaschalis]

how to controll the amper for the electrode