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 I want to gently wipe the dust and such off my secondary mirror, but I’m really afraid I’ll scratch it. What is the best way to clean a mirror?

Greg

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Hi Greg,

I use a Giotto rocket blower to remove dust.

Anything that sticks, you could push loose with a camel hair brush. A new and unused, nice and soft make-up brush is also good.

Giotto.png.5eb58e9225fe7b88d047c70ff4e972fb.png

 

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this a big no no(photo)  agree with above camel hair brush plus air blower

images.jpg

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If it's really grubby or has deposits that the blower or brush won't shift then the technique shown here for main mirrors works well on secondaries too. The secondary does have to be removed though and the spider reset and collimation readjusted.

Edited by almcl
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13 minutes ago, Ruud said:

Hi Greg,

I use a Giotto rocket blower to remove dust.

Anything that sticks, you could push loose with a camel hair brush. A new and unused, nice and soft make-up brush is also good.

Giotto.png.5eb58e9225fe7b88d047c70ff4e972fb.png

 

Its funny that you mention make-up brushes but I have several for my camera lenses as well as a stock of red nail varnish for electrical use and making white leds red, felt strange wandering around the ladies section of the chemist at first but got used to it :icon_biggrin:

Alan

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30 minutes ago, Alien 13 said:

Its funny that you mention make-up brushes but I have several for my camera lenses as well as a stock of red nail varnish for electrical use and making white leds red, felt strange wandering around the ladies section of the chemist at first but got used to it :icon_biggrin:

Alan

suite you sir. don't mind if I don't

Edited by fozzybear
stole wifes new foundation brush
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Geez, Alan, your vanity must be even more impressive than mine:

capture_002_13012019_000838.png.1b93dc19a85cfc5fdcb15fa6be1a7213.png

 

 

Edited by Ruud
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Your scope is brand new, I would hesitate from cleaning it unless by some awful stroke of bad luck it was left in a corner of the floor in the manufacturing plant before it was installed, which I doubt. Most of us here haven’t cleaned our mirrors in a decade, it’s a temptation which many new to the hobby can get carried away with and, risk damaging  mirrors. It takes an awful lot of dust to warrant a cleaning. Many don’t ever clean secondary’s since they face down most of their lives and dust doesn’t settle as much as the primary. If you see some bits of dust ignore it, otherwise you’ll be cleaning your mirrors once a week.

Edited by Sunshine
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As above, but if you want to learn how it all works, go ahead, its the only way to learn, but you'll need confidence in completing the task.

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I think the most important thing to note here is that unless the secondary is literally caked with dirt you will see absolutely no noticeable improvement after it's cleaning, a little dust will be completely unnoticeable.

I clean my mirrors once a year in a process similar to that posted in this thread but the environment in wich the scopes live and work is very dirty and humid, my oldest mirror is twenty years old this year and it's coatings have held up well due to careful cleaning only as needed. 

Microscratches are accumulative and proper cleaning or no cleaning are the only means to prevent them occurring 🙂

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Thanks guys! The reason for the post was that I got a small fingerprint on the secondary and wiped it with a dry cotton cloth. Seemed to work fine but was afraid I could damage the mirror.

 

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For future notice, as far as I know, and don’t quote me, I believe there’s nothing you can safely wipe your mirrors with when dry, cleaning should be done wet, and in most cases immersed in water. Be careful when doing anything with your hands around the mirrors and, ALWAYS have the scope in a horizontal position when handling screwdrivers, flashlights, or anything you’re poking into the optical path. That way if you drop something it won’t fall right down on the primary, causing a nausea attack for sure!.

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Hello if you want to clean without remove you can do by this way: use the blower with brush first like the post before, use it very carefully. After go to pharmacy buy an good quality cotton ( like surgery quality) and use this product:

https://purosol.com/products/purosol-lens-cleaner

Best regards

Edited by Pancho61
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Mirror cleaning is a subject that crops up fairly regularly on SGL.
Many remedies are suggested, and I think I have come across about two that
I would consider dangerous.
(None in this thread I might add. )

Some surfaces may be manufactured with a protective quartz over  coating
for example, but that does not protect it from poor cleaning methods.
The surface at all times must be treated with great care, the secondary is just as important as the main mirror when
cleaning is to be attempted.
Never be alarmed by what you might consider a dirty mirror surface, and think very long and hard before 
removing for cleaning. Bear  in mind, that a
Seemingly dirty mirror, will  perform much better that a badly cleaned one.
Ron.
 

Edited by barkis
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