Does my mirror need cleaning?

[Ganymede12]

Hey guys, 

It’s been a long while since I’ve been active here, or even been out with my telescope. 

I looked at my Skyliner 200p’s mirror and it’s collected a lot of dust since I’ve been away from it. 
 

Does this much dust warrant a cleaning with water or should I just leave it be? 

Edited March 26, 2020 by Ganymede12

[Hallingskies]

That looks OK to me, no need to touch that.

[Ganymede12]

Thanks for the speedy reply Hallingskies! 🙂

[Timebandit]

 

 

Hello.  Unless it is absolutely filthy ,then I would leave it alone. Sometimes if its just loose surface dust then a non contact small air blower , just to remove surface dust is maybe a worthwhile exercise.

 I hope this helps 

 

 

 

[joe aguiar]

To me doesn’t look too good it looks like it has a film on it

Since the mirror is already out of the telescope you might as well just clean it now and then put it back in

joejaguar

[Captain Scarlet]

If it’s just dust then leave alone. But if it’s pollen or anything sticky or growing then it likely needs attention. There look to be some splodgy areas on that, maybe mould growth on some spots? I’d at least give it a rinse in warm soapy water to get rid of those.

Cheers Magnus

[Ganymede12]

I tried blowing some of it off with a little hand pump thingy I have (not sure what it’s called). Everything in the photo is stuck on. 

I just took it outside and it was *just* about able to make out the Leo Trio and maybe also the pinwheel galaxy (though I’m not sure if my brain was just seeing what it wanted to with the latter).

If it needs cleaning, how best to go about it? 

 

 

[joe aguiar]

Just rinse in the sink with warm soapy water but just add one drop of soap and then rinse it with distilled water then let it dry

joejaguar

[Ricochet]

Getting hold of distilled /deionised/reverse osmosis water might be an issue while we're under lock down. In that case I would simply put the telescope outside, uncapped and facing east of the sun. In the event that the stuff on your telescope is a fungus the UV rays will kill it and prevent it spreading. You can then safely leave cleaning the mirror until the ships are open again and you can source the correct water to rinse the mirror.

When you do remove the mirror for cleaning I would create a mask for the mirror edge. The edge coating looks like its degrading a little which will be scattering light over the view and reducing contrast. 

Edited March 27, 2020 by Ricochet

[Guest]

Is de-ionised water any good for cleaning it?

[Captain Scarlet]

13 minutes ago, merlin100 said:

Is de-ionised water any good for cleaning it?

yes, it's distilled, means final rinse-over won't leave any residue

[Jonk]

Not necessarily... deionised water obviously lacks ions.... this can cause issues when in contact with metal (aluminiumised mirror).

It may also contain organic content which is undesirable.

Use pure distilled water only if possible.