Main Mirror Spring Clean.

[Ciaran Meier]

Popped the primary mirror from my 8" newt for a bit of a spring  clean. Before and after shots. Looking forward to my "first light" hopefully later this evening. 

 

[paul mc c]

Nice one....Orion Optics clean up well,looking good for tonight hopefully.

[Guest]

Unbelievable, the difference!😲

[John]

It does look much better but you can have a surprising amount of crud on your mirror without it making much difference to what you see.

 

[Ciaran Meier]

Mirror re-installed and rough collimation. If it can split a close double I'll leave as is. Clearing up nicely here in Belfast. 

[Ciaran Meier]

Scope operating well, managed a few nice doubles in Gemini then clouds rolled in.   Met Office online forecast gave, and is still giving clear skies.  BBC online forecast predicted a cloudy sky.  I'd say currently 80% cloud cover here.  Usually the Met forecast is quite accurate, but sadly not so in this case. Oh well, maybe tomorrow......

[JTB]

I am just starting out in Astronomy and one of the telescopes I own is a Celestron Astromaster 130EQ OTA that was given to me after being left in a shed for several years. It literally had insects crawling out of it when I picked it up and it is definitely in need of a clean!

I am curious to know what method you used to clean the mirror. There are a number of you tube videos showing the use of washing up liquid, cotton wool and a final rinse in distilled water – is this a good method to use?

The inside of the tube also needs debris removing from it and I wonder what is the best method to achieve this?

[Ciaran Meier]

Hi JTB

I rinced the mirror with a little distilled water.  Held the mirror up to drain off the excess water that pooled in the concave hollow.  Then gently with the corner of a lint free cloth I flicked away the remaining water working from the centre of the mirror to the edge.  Then with a fresh piece of same material I gently dried the mirror working in a circular motion from the centre outwards.  Will take a while so be patient. 

If the mirror is really bad and has actual gunk on the glass then a bit of washing up liquid may be needed.  My advice would be not to apply it directly from the bottle but dilute it first and apply with a bit of cotton wool.  Then rince and dry as above. 

As for cleaning the tube I'd advise removing all the optics and give it a good clean with warm water.   Don't be tempted to scrape the inside of the tube as it's probably coated with a black non reflective paint that mustn't be damaged. 

All the best

Ciaran. 

[Avocette]

On 09/04/2020 at 00:26, JTB said:

I am curious to know what method you used to clean the mirror. There are a number of you tube videos showing the use of washing up liquid, cotton wool and a final rinse in distilled water – is this a good method to use?

I recommend the ‘full immersion’ method illustrated by Steve Richards (steppenwolfwest) on YouTube 

If you prop the mirror on its side when you have carried out the final rinse (real distilled water if you can get it  rather than non deionised water) you won’t need to touch it any further as it dries naturally

[JTB]

Excellent - thank you I will try this.

Is it the same process for the secondary mirror and is there a special way to clean the inside of the OTA?

They really is just as filthy!

 

Cheers

 

John

[Avocette]

For the secondary mirror (and I checked with Steve before doing this) I first used a plastic bag held by an elastic band around the oval edge of the secondary mirror to fully enclose the mounting metalwork, and then did the same full immersion washing as the primary. Similarly, no need for any touching to dry when rinced with distilled water and propped up to drain naturally.