By -
Date 09-09-2005 23:20
Hi Danny,
Sure, a gas torch will cause the metal to oxidize if sufficient temperature is reached. Like we said, that color is a chromium depleted oxide layer. It will stay a chromium depleted oxide layer until it is removed. This being a motorcycle muffler ( I ride them too, well, not your kind but H-D's) and the muffler's are not all that thick, so your muffler is going to stay discolored throughout. The chromium depleted oxides are only on the surface, but the muffler will stay discolored all the way through. The heat from a motorcycle exhaust is not quite as high as the heat from the welding process, and that is what determines the thickness of the oxide layer. Sorry, that's just the nature of the beast. On my M/C the heat tint is only where the pipes bend coming right out of the head so I put heat shields on mine to hide that color. Now, you can't even tell it. :-)
Chuck
Chuck