Salt air and mirror coatings ?

[GrahamL]

I live about 2ks max from the beach and have been wondering if the salty
air necessitates a mirror clean more often than a more inland location.
Yeah.. I do see the dust on the mirror ..and that dosn't bother me
but I do know the night air can be very salty at times and was thinking more along a ongoing preventitive wash rather than getting a little loopy over a few dust specks.

TIA:)

[Blue Skies]

Yes, I think you will need to wash your mirrors a bit more often to slow the oxidisation process. I did hear a story from locals about a big Obsession scope near the beach here that was used without a shroud and the secondary didn't last all that long. But you may also have to accept that you will be looking at realuminising more frequently than some. But I've also used badly oxidised mirrors before and sometimes you can't tell what state they are in. Depends how picky you are.

[ballaratdragons]

My sons have a very badly stained Primary mirror in thier 8" reflector that has not been re-aluminised in about 18 years! and it still gives fantastic views!!!

Seeing as I thought it would need re-aluminising anyway I scrubbed the daylights out of it to try remove the oxidisation and the stains but they didn't budge, and even after the brutal scrubbing I gave it the mirror STILL gives fantastic crisp images!!!!!!!! and . . . it was never over-coated! :eyepop: Just bare Aluminium.

Don't ask me why this is so, Bert aluminised it, ask him why.

I am not suggesting you scrub your mirror :lol: