Rich - you're giving away your drinking preferences. Everclear is an alcoholic beverage, if you can call pure alcohol a beverage... -----Original Message----- From: Richard Tenney [mailto:retenney@yahoo.com] Sent: Monday, March 24, 2003 11:26 AM To: Astronomy in Utah Subject: RE: [Utah-astronomy] SCT or Newtonian? David, What is Everclear, and where can you purchase it? I've never heard of it. --- David Dunn <david.dunn@albertsons.com> wrote:

Even a mirror that has been to Monte Cristo and Antelope Island many times a year doesn't need to be cleaned very often. I clean mine every two years or so. I might clean them after one year if they were real dirty. To clean my mirrors, I take the mirror still mounted in it's cell out in the back yard. I run a large quantity of water over it. If there are any spots that need soap I use a little Joy detergent in a lot of water. I use a cotton ball to wipe, no pressure, in one direction only. I then rinse the mirror with a lot of tap water again until the soap is all gone. They I rinse with distilled water. Then I rinse with Everclear. Everclear doesn't seem to leave a film and gets the water off immediately. This process allows you to leave the mirror silconed into the mirror cell so you can just put the cell back in the scope and start observing again.

I have also heard of people using compressed air to blow the dust off of the mirror. I haven't seen any damage to the mirrors that I have seen where this process was used.

-----Original Message----- From: Chuck Hards [mailto:chuckhards@yahoo.com] Sent: Monday, March 24, 2003 10:22 AM To: Astronomy in Utah Subject: RE: [Utah-astronomy] SCT or Newtonian?

Words in caps are for emphasis, I'm not shouting.

This subject is too lengthy for me to go into detail right now (at work, as usual) but the secret is PATIENCE and NOT wiping right away. Let the mirror soak in warm water for a few hours. This will loosen most of the dirt and it can be rinsed off using only the pressure from the tap. Wiping is best done judiciously, after a soak, and using only the best grade of cotton, only one wipe per cotton wad, one direction only, rotating as you wipe. All rinsing should be done with distilled water, then drip-and-air dry. If you need to use soap, you waited too long to clean, but let the mirror soak in SOAPY water if it's really filthy.

This is just a quick description, many nuances remain undescribed.

Cleaning requirements are a good reason to avoid mounting mirrors with silicone glue. You won't be observing the same night that you cleaned the optics if you use silicone.

Of course, it goes without saying that you need to keep the mirrors COVERED when not in-use. My 6" f/8 is now 4 years old, and the mirror has hardly any dust on it.

C.

--- Joe Bauman <bau@desnews.com> wrote:

...

How 'bout a scouring pad? Just kidding, but I think I may have damaged either my corrector plate or the mirror by cleaning with usual photo lens cleaner material, although I was extremely careful. But I think there's really something wrong with my optics now. Thanks, Joe

...

The next obvious question to me is, what it the right (careful) way to clean a newtonian mirror?

I have read somewhere that using a mild dish soap like Dawn is prefered. Any wiping or rubbing will grind dirt into the mirror. So how do you get the dirt off? How about using an old shaving brush (probably couldn't find one these days) or a photo air brush?

Jim Gibson

__________________________________________________ Do you Yahoo!? Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop! http://platinum.yahoo.com

_______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com

http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy

_______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com

http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy __________________________________________________ Do you Yahoo!? Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop! http://platinum.yahoo.com _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy