what determines when copper is bare bright and not?

I believe the difference between #1 and #2 is that #2 is not clean and you can make #2 into #1 by removing elements of solder, paint and other contaminates.

Quick video here helps:

Originally Posted by NoviceScrapper

I believe the difference between #1 and #2 is that #2 is not clean and you can make #2 into #1 by removing elements of solder, paint and other contaminates.

Quick video here helps:

Just sayin, most of the vids from them are not too helpful. Not enough info in tmem