mucky secondary mirror = image degradation?

[Craig_Billo]

I have a slightly mucky looking secondary mirror, Its water spots mainly from dew and misting going from hot and cold environments. What effect will this have on the image?

Also is there any decent house hold cleaners i can use as there isnt a 'local' astro shop and im looking to get out this evening if possible so ordering online is out of the question for this weekend.

[Trull]

Unless there's significant (>10% of area obscured) deposits, I'd be surprised if any to be honest.

Go to Halfords and get a bottle of distilled water (next to the battery area), and you can rinse off the surface with that. I'd use a fine sprayer after a little dunk into lightly soaped warm water to loosen. Never touch! Don't use household cleaners unless you fancy a new mirror.

Why not use a poly bag to protect the mirror while it warms up, for the future?

[Craig_Billo]

thanks for the heads up on that Trull. Will prob leave it for now as i dont think its having any serious effect on my viewing, i have a little ocd when it comes to anything i have to look at/through, be it my camera, rifle scopes, Tv or aquarium being perfect but thats a different ball game by the sound of it. I will live with it for now and do a little more research on mirror cleansing.

[Daz Type-R]

I would not even use that - only proper lense/mirror cleaner designed for scopes is the only products I would use with a special lint free cloth. Somebody answered this very same question recently and they listed all the stuff you should do in order, I will see if I can find it and post the link.

[Daz Type-R]

Not the post I was thinking of but try this one....

http://stargazerslounge.com/beginners-help-advice/131334-whats-best-way-maintain-telescope.html

[ollypenrice]

Leave it alone. It has to be bad to have any effect at all. My Dob lives outside in a dusty roll off and gets a wash in the shower (the mirror that is!) once a year at most. It is in constant use and where I live is dry and very dusty by UK standars.

Olly

[Craig_Billo]

thanks for all the info, i will be leaving well alone for the time being, scope is only a month old so wont be as dirty as i think by the sound of it. with a bit of luck these clouds clear and i can have a look 'through' it instead of looking 'at' it, although it looks sexy sitting in the corner of my bedroom id rather it was in the field being used.