This is not strictly a question about my gas forge, as it has never done this before and I do not believe it's function plays into the question.
Today, upon first firing up the forge, a distinct green flame curled up from the gas forge door.
I have never put copper or zinc in any form into this forge. I avoid anything but plain steel.
I was working on the same pieces yesterday, with only the good orange flames licking up.
The only variable today was a full night of rain.
My shop has concrete floors, but water comes in through the bottom and through a couple of pinholes in the galvanized roof.
There was standing water around the pieces I put into the fire, with water coming off the galvanized roof, and nearby were unplugged power tool plugs that I unwisely forgot to move.
My thought is that the rain dissolved a trace amount of zinc or copper from one of these sources, and that it evaporated onto the steel when I lit the forge.
if anyone has any thoughts on how this unusual color came to be, please share it!