When to clean primary mirror

[Cuto100200]

Hi Guys

Just a quick question regarding the primary mirror, obviously eventually dust, and whatever else may get on the mirror, how much of this does it take to actually effect visual quality, and when does it need to be cleaned? 

I can spot a black thing on mine, its very small and i imagine it's probably a part of a leaf that could be easily blown, or wiped off though it hasn't seemed to effect visual quality whatsoever, or at least from what i can tell

Thanks

[kerrylewis]

The common advice can be summed up in one word - don't. But I tend to ignore this and give mine a clean every 12 months or so. I don't know what your scope is but mine is a Skywatcher Flextube 350 and the mirror is easy to remove in its cradle and I dunk the whole thing in the bath,

There is lots of advice on this forum and some good videos on Youtube regarding the detail of the operation. Basically I clean with a weak solution of Fairy liquid and rinse off with distilled water. I lightly skim over with a cotton wool pad to remove any residue. It's nothing to be afraid of basically

Kerry 

[Timebandit]

 

 

 

Lots of debate on this one. Personally unless it is really bad then I would leave it alone. I did read an article some years ago about the surface of the primary can get very fine scratching on it even if you go very very carefully with your cleaning. So I would leave well alone.

 

 

 

[Carbon Brush]

Mirrors can have a lot of muck on them before you notice image degradation.
One slip in cleaning can do a lot of damage.
If in doubt, ignore and look again another day.

I always keep these statements in mind before thinking about dismantling a scope.

Having said this, I have cleaned a few mirrors over the years.

HTH, David.

[Mr Flibble]

I leave my mirror alone......until it starts to look really gunky.

Mine will fit in the kitchen sink. I use a little bit of washing liquid and let it soak for a minute then rinse off with distilled water. Prop it on its side to drip dry.

At a guess I think I've cleaned it twice in the last eight years or so.