John Meiners said:
I have a Celestron 9.25" SCT. the front lens (where the dust cap covers) has never been cleaned... does anyone know of a site that discribes a safe and effect way to wash (clean) the glass... thank you, John M
The best thing? DON'T. Not unless it needs it. Really needs it...as in more than a few fugitive dust specks.
That said, cleaning an SCT corrector is not dangerous. It's more like a camera lens than a first surface mirror.
What have I been doing successfully for the last 30+ years? What have I been usin'?
Windex
Kleenex
By "Windex," I mean the ol' fashioned blue stuff, not some perfumed stuff designed to make the latrine smell like posies.
"Kleenex" means original white WITHOUT LOTION (triple check that...the other day I thought that was what I had grabbed, and shortly had a mess of a corrector).
Spray Windex on tissue, not on corrector. Clean radially from the secondary, rotating the tissue and using new tissues frequently.
When done, swab with dry tissues until the corrector is dry and squeaky clean.
If some lint is left behind, disperse that with canned air (held upright and about 18-inches from the surface) or a camel's hair brush.
I have used Windex on StarBright, UHTC, and XLT correctors with excellent results.