Thanks for the information Bert, I wasnt aware of exactly how the process was done, Id always wondered how Quartz was evaporated onto a mirror.
Seeing Issac run his fingernails while pressing hard over a test mirror and not marking it was amazing. The mirror should last the rest of my life, as I treat it very carefully, store the scope tube on its side and covered, not allowing dew on the mirror and washing it very carefully. Even the bare Al coating lasted me many years
The secondary has its original coating (Quartz overcoated) and is still pristine despite its 1986 vintage.
Scott