O/A welding with copper wire??????

[Wild Turkey]

Welding question from another board ("HAMB" -- old style hot rods and customs)

I wanted to weld a drain plug nut on my turbo 350 pan to make it easier to change the oil, so I grabbed an old coathanger and the oxy/acet and started melting the wire.

I got a surprise! The wire was a copper wire out of a piece of Romex!
What the heck, I kept welding. After I installed the pan I leaned hard on the wrench to see if it will hold up and its fine, but what did I do? I didnt use any flux and it looks good, doesnt leak and doesnt twist off.

I've never heard of welding (brazing?) with copper. Do we have anyone who can explain this?

Assuming pan was steel how would this work?

Would the wire have been an alloy?

[usmcpop]

I didi see mention of brazing a steel alloy with pure copper, using a reducing flame and no flux.