Posted by Rick Denney on February 21, 2002 at 11:22:55:
In Reply to: Red Rot posted by Callmeapple on February 21, 2002 at 10:53:01:
Red rot is characterized by small red dots that bubble up from underneath the lacquer. When you see it on the outside of the horn, it means that it has already worked through from the inside. This doesn't really spell disaster, because it may or may not reflect a large spot of corrosion. But it isn't something any of us want to see. I have one or two spots like that on my Yamaha, but so far no problems (I will be more careful about having it cleaned, though).
But that isn't the same as patchy superficial red coloring that sometimes appears on unlacquered brass. This mild surface dezincification starts on the outside and usually stays there. Normal polishing will remove it. Heating with a torch will accelerate its appearance.
It's like the difference between superficial rust on your car, solved by a little Naval jelly and paint, or perforating rust caused by corroding salt on roads, which requires a whole new fender.
Rick "who has seen both kinds" Denney