If you want to call we will send you a jar of Black Flux free and some
braze alloy. Call Tom or Emily at 800 346-8274. We usually sell
this in large lots instead of giving it away but I like your attitude.
It's people who won't quit that make a better world.

flux info
http://www.carbideprocessors.com/Brazing/book/13.htm

Braze alloy info
http://www.carbideprocessors.com/Brazing/book/12.htm

Sand or grind the material down to a rough / gray (smoetimes called '
white' metal) and use a lot of flux. When you are through you still
want to see some Black Flux left.

cleaning
http://www.carbideprocessors.com/Brazing/book/11.htm

For a temperature / color chart go to
http://www.carbideprocessors.com/Brazing/book/15.htm

This is steel under lab conditions and it is just the surface. You
want to heat the part all the way through so you will need to get it
hotter.

tom