Mirror clean required

[Garethr]

Just spent a happy 10 mins playing with my new Hotech laser collimating my scope ( thanks to santa).

Shined a torch down the OTA after finishing and  the mirror is absolutely filthy.  Always worked on the theory if it ain't broke it don't need fixing but had the scope from 2nd hand for 5 yrs now and as imaging is my main use of the scope it seems daft to spend hours collecting every photon possible but using a dirty mirror.

Time for a clean and play with the Hotech again me thinks. 

 

Gareth 

[BXRO]

Good luck, don't use to much windoleen ?

[David Smith]

Did mine over Christmas too. Remember you will need a sight tube, collimation cap or cheshire as well as the Hotech to put the scope back together again.

[mikeyj1]

Gareth,

so how are you going to clean it?  Mine also needs a clean; the other night the dew got so heavy I have streak marks where it was running down the mirror  

I saw the 'Poly-Clean in Astronomy Now, but its pretty expensive, (although obviously cheaper than a new mirror :-/ )

maybe there is already a good thread on here about mirror cleaning, but i havent come accross it yet

cheers

Mike

[wimvb]

Just cleaned the mirror of my 150PDS. It isn't too hard. There are several clips on youtube that show you how.

After removing the mirror from its cell, I just soaked it in luke warm water with washing up liquid.

Did this twice. Then rinsed with tap water and finally with distilled water. Sprayed some Baader wonder fluid (used for cleaning lenses), and wiped off most of the remaining fluid with a microfibre cloth (Baader). During a rinse, the center mark came off. Had to replace this with a home made from an adhesive label.

All worked fine, and collimation seems ok also.

 

Good luck with yours,

[Charic]

24 minutes ago, Garethr said:

......Shined a torch down the OTA after finishing and  the mirror is absolutely filthy

Will always look worse by this method, due to the magnifying effect of the primary, that's how I see it.

It won't look so bad once the mirror is out, but its a simple task (oops!) for many folk.

The feeling of knowing its clean, and properly setup after use is very rewarding.

"Don't use  too much windowlene " as above? I have once cleaned using this method, there's no physical damage that I can visualize on the mirror except  the solution dislodged  the donut, so had to fit  a new one, but this method of cleaning is frowned upon  by just about everyone!
Stick with the tried and tested methods.

[David Smith]

@mikeyj1 I have used the method described in this link many times

http://www.skyandtelescope.com/astronomy-resources/caring-for-your-optics/

[mikeyj1]

2 minutes ago, David Smith said:

@mikeyj1 I have used the method described in this link many times

http://www.skyandtelescope.com/astronomy-resources/caring-for-your-optics/

Thanks David, i have used the washing up liquid method on my old scope, but wondered if there was a better option.  Thanks for the link, useful!

Mike

[Tim]

 

 

[wimvb]

My method was very much like @Tim's clip, but without wiping the mirror, and finished off with Baader wonder fluid to avoid dried in water marks.

As I already mentioned, the center mark came off, but it's easy to replace. Just make sure you put it in the very center, otherwise it will affect collimation.

[Garethr]

All done. 

Used the warm tap tap water sluice method first but there was still loads left on the mirror.  I think a spider got in there somehow as there were a few webs in the OTA.

Then soaked in a weak washing up solution for 10 mins and another rinse under tepid water still a few bits of spider pooh on there so cotton wool wipes rolled gently over the mirror and a sluice with the tap again seemed to get rid of the white spots.  A final rinse in deionised water and left to dry almost vertical.  Needed the corner of a kitchen towel to soak up a couple of stubborn droplets but all seems well.

Refitted and used the cheshire first followed by the Hotech and all seems well. Treated the secondary to a bath as well.

A happy hour spent giving a bit of TLC to something that gives me hours of pleasure although SWMBO was a bit ticked off at the amount of cotton wool swabs used

Looking forward to clear skies again.

Happy new year to all

 

Gareth  

[wimvb]

Cotton swabs must be the cheapest investment you can make in this hobby. Glad you got rid of stains and critters.

Happy viewing 2017

[JohnSadlerAstro]

Hi,

I simply gently blew mine using an airbed pump; it got most of the dust away without me having to touch or wet the mirror in any way.

I don't know if that's frowned upon, though.

John

[ronin]

Just as information there is a thread over on CN about cleaning mirrors with horse shampoo, if intereste look in their Equipment section. One post points out that a professional scope over there uses that so it cannot be all bad, another has a scenario about how it could have occurred, another explains the possible reason (chemistry) behind it.

So the extremes at present are: Don't even look at it never mind actually clean it, to, get the horse shampoo out and lather up.

[estwing]

You really don't have to clean a mirror every time it gets a little dirty, you won't believe how dirty some are and still get used quite happily.

[sophiecentaur]

Oh boy, what a relief. I just found this recent thread and it has a different message from other threads I have read onSGL and elsewhere. The message was always doom and gloom and "don't touch it Pike". I have gone as far as buying my gallon of distilled water and a new pack of cotton wool so I shall be doing it (very carefully of course) soon.