# Optical flat repair



## Brento (Dec 31, 2021)

I have a Van Keurnen Optical flat that i never realized was actually an optical flat. Now it looks pretty dirty and im wonder what can i do to clean it and is there anything i should do to store it. I see the outside is a little gouged looking unless it is just mung from being dirty?


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## pdentrem (Dec 31, 2021)

Is it etched or in need of a good cleaning of the surfaces?


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## Brento (Dec 31, 2021)

I honestly don’t know bc i don’t know much about them to tell what you even mean.


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## pdentrem (Dec 31, 2021)

To clean optical glass.
Get some supplies
cotton balls
distilled water
Dawn Regular dish soap
a bowl

Make up a mix of Dawn and distilled water. Place flat on CLEAN pad (paper towel) don’t worry about lint at this time. Soak the glass for 5-10 minutes. Swish the glass around a bit to hopefully cause some or all the dust etc lift off. Do not rub anything! 
Rinse the flat with some of the water.
Still dirty?
Refill the bowl. Now use as many cotton balls as required and in one straight pass without rubbing swipe across and roll the balls at the same time so any debris is picked up but not allowed the touch the glass again.
Rinse with the water and leave the glass standing up to let the water run off. 
Hopefully a lot cleaner!

if the glass is etched by chemical, you can only clean and use as is.

Store is a felt lined case, same as the ones we purchased. Microfiber cloth to wipe any dust off before using it on just as clean part.
Pierre


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## Brento (Dec 31, 2021)

Can i store it in a micofiber cloth in my Gerstner?


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## pdentrem (Dec 31, 2021)

Don’t see why not. Crown Royal Bag would be a good touch as well!


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## Dabbler (Jan 1, 2022)

Your best bet is to store it on its side so that the two precision surfaces don't have to touch anything at all.


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## Navy Chief (Jan 1, 2022)

If you have an ultrasonic cleaner a cycle through it with just distilled water could help remove a lot of the grunge without harming the surfaces.

Sent from my Pixel 5 using Tapatalk


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## Brento (Jan 1, 2022)

I unfortunately do not have a ultrasonic cleaner so by hand i will be doing. What kind of light do you need to use for these?


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## Dabbler (Jan 1, 2022)

To use an optical flat, you use a monochromatic light source.  The common one to use is a sodium emitter, but they are pricey. 

- I plan to use a diode green laser with a 2 level filter an diffuser.

[edit] You have to use caution using a laser emitter, all the caveats, and warnings.


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## pdentrem (Jan 1, 2022)

Monochrome light like Christmas lights in green. Dark adapted eyeballs see green better in the dark. You can use a CFB and simply use colored sunglasses as the filter. Darker the room the better of course.
Pierre


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## woodchucker (Jan 1, 2022)

I remember watching a guy that makes optics (he's on you tube)...
If I remember correctly, he uses a sprayer to shoot dirt off.. search him out on you tube.
He's pretty amazing to watch.


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## homebrewed (Jan 2, 2022)

I'd highly recommend wearing particle-free Nitrile gloves when handling the optic.  That goes for cleaning AND using it.  Skin is a great particle source.


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## woodchucker (Jan 2, 2022)

woodchucker said:


> I remember watching a guy that makes optics (he's on you tube)...
> If I remember correctly, he uses a sprayer to shoot dirt off.. search him out on you tube.
> He's pretty amazing to watch.


I went searching my history, he may have been on Vimeo, and I got their from a link..


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## savarin (Jan 2, 2022)

When you stand it up to drain the water off and the water beads up its still dirty.
Follow pdentrem's system again.
What ever you do dont scrub it.
Heres two methods in more detail.


			Cleaning a Telescope Mirror - A New Technique
		









						How to Care for Your Telescope Optics the Right Way
					

The telescope optics will probably work fine with some dust on it, but if it's really dirty, you may want to clean it—carefully—with the help of our guide!




					skyandtelescope.org
				



What will you be using your optical flat for?


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## Brento (Jan 2, 2022)

Nothing as of now but it is nice to have for in the future.


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