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RCOS Mirror
March 13, 2010
The 16" main mirror of my RCOS was cleaned March 13,
2010, initially using a spray-on polymer compound made for
first surface mirrors, followed by a more standard
water/Windex/detergent cleaning afterwards. The follow-on
cleaning was needed since the polymer did not remove the
dewed-on material from the mirror surface. The polymer
manufacturer has instructions on how to remove water spots.  
This involves spraying purified water/cleaner on the mirror
surface, and using slightly more of the polymer spray than
normally required.  I followed these instructions, but my
mirror hasn't been cleaned in 4 years, and as a result of a few
dewing events there was too much material 'welded' to the
mirror surface. The polymer peeled off cleanly as advertised,
and on a mirror without significant dewing issues, it would
likely have worked well.  In the future I plan on using my
CO2 snow gun more often. Perhaps this will permit the
polymer method to be more effective.
Click on the thumbnails for larger pictures.
Supported for mirror
cell removal
Dirty mirror in cell
ready for polymer
Masked for polymer
After polymer
Side view of mirror
Front view of carbon
fiber tube
After drying overnight
Peeling the dried polymer
Mirror after polymer
cleaning-note welded
on residue
Mirror cell after
mirror removed for
wet cleaning
Mirror after
Safely back together
Supported for mirror
cell removal
CO2 Snow Gun
Backplate ready for
Collimation test after mirror reinstall
Click here for later mirror re-coating