Pan,
Flame sprayed aluminum is a header coating that gives a unique appearance, is permanent, will not discolor and prevents rust. I first saw it as a coating on air cooled radial aircraft engines and thought "That would look really cool on headers". So I took a set of headers I had just built to the aircraft engine shop where I saw the process applied to cylinders and had the headers coated. The result was perfect in every way.
That was decades ago and apparently aluminum flame spraying is still offered:
https://www.thermalspray.com/thermal-spray-coatings/thermal-spray-coating-processes/metalizing/https://appliedmaintenance.com/what-is-tsa.htmlI last had flame spraying done about 15 years ago on this roadster exhaust, and the coating is unchanged from the day it was applied. For a shiny surface the flame sprayed aluminum coating can be buffed and looks like any other polished aluminum.
Ray W
