So I started messing around with trying to get a rusted look for metal without actually coloring it. This is what i got after a couple minutes messing with it. Its not meant to impress. Its just to show what I want it too look roughly. Could someone with a more "artsy" touch could smooth it out for me. Thanks for the help.
Heat does not make it look rusty. Heat makes it bright orange, heating it, thus like in reality. THUS you should use deco layer, to make it brown, instead of orange. But do how you want.