Google BernzOmatic. That's what I use on irons. If I do get any discoloration it's pretty simple to polish the iron again.Whats the type of torch you guys use? Is it just like a handheld gas bottle thing?
For woods it's a heat gun every time. Too easy to mess up one with a flame.
Really, a torch is just a tool for the impatient. The heat gun will do the job, just in a bit more time.