epmedia

The method with plate glass on heads works well. I use the Norton oxide paper (just one sheet, per head) in my ghetto yard Stage1 shows how bad the surface variations were between the chambers: (plate glass also shown, but 1/4" is minimum you want to go, and must check glass for flatness before proceeding) Stage 2 shows most of the imperfections gone: Stage 3 and 4 came afterwards...