Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Water Spots??

This topic has been archived. This means that you cannot reply to this topic.
36 replies to this topic

#1 Guest_**DONOTDELETE**_*

Guest_**DONOTDELETE**_*
  • -----
  • topic starter

Posted 17 May 2004 - 11:37 PM

I had my first run in with Dew Saturday night and WOW.... :shocked: what a mess!!

After taking the scope inside and leaving the OTA cap off for it to dry, I noticed the next morning that I now have water spots on my XLT coatings! :shocked:

Any suggestions from other SCT owners with XLT coatings on how to clean this?? I recently purchased cleaner and soft cloths from a camera store, but I'm leary about using it on these coatings.

Any help / suggestions are greatly appreciated! :)

#2 jrcrilly

jrcrilly

    Refractor wienie no more

  • *****
  • Administrators
  • Posts: 35396
  • Joined: 30 Apr 2003

Posted 18 May 2004 - 08:13 AM

http://www.arksky.org/asoclean.htm

It's available pre-mixed from www.optcorp.com or at:
http://www.astromart....asp?cid=272107

#3 Blueshark928

Blueshark928

    Mercury-Atlas

  • *****
  • Posts: 2853
  • Joined: 19 Feb 2004

Posted 18 May 2004 - 10:16 AM

Thanks for the link

#4 Guest_**DONOTDELETE**_*

Guest_**DONOTDELETE**_*
  • -----
  • topic starter

Posted 18 May 2004 - 10:35 AM

First a disclaimer, this technique works for me, use it at your own risk! Here is what I have done to clean coated optics (not aluminized mirrors). First, a little background. I wear glasses with the thinnest plastic coated lenses that I can get. Plastic lenses are very soft compared to glass and the coatings are very delicate. Cleaning these glasses requires a special cleaning solution and a special cleaning cloth. I bought the "optical cleaning kit" and follow instructions and it works well, no scratches and clean glasses. It occured to me that the cleaning kit may work on optical surfaces such as eyepieces, corrector plates, etc. (again I emphasize NOT aluminized surfaces). I experimented with a cheap eyepiece and it worked great. Then, I cleaned the surface of the corrector lens of my SCT. No problems.

I got my "optical care kit" from Costco, but I suspect that any optometrist office sells the equivalent. Just make sure it is for cleaning coated plastic lenses and then follow the cleaning instructions.

I would be interested in hearing if others have tried this technique and if they have also been successful.

Russ Schnitzer

#5 bierbelly

bierbelly

    Voyager 1

  • *****
  • Posts: 11544
  • Joined: 23 Jan 2004

Posted 18 May 2004 - 11:05 AM

0000 steel wool?


But really, it's my understanding that isopropyl alcohol works wonders in cleaning optics, without damaging the coatings. Just be sure that you get the rubbing alcohol without other additives, just 70% alcohol and water.

#6 werewolf6977

werewolf6977

    Lord High Smasher

  • *****
  • Posts: 9034
  • Joined: 15 Dec 2003

Posted 18 May 2004 - 11:50 AM

The Arksky.org, aka Dr. Clay's cleaning solution is the best I've found. You can make oodles of it for under $5.00 usd. I keep a spray bottle of it around just in case. Pete

#7 Don W

Don W

    demi-god

  • *****
  • Administrators
  • Posts: 22392
  • Joined: 19 May 2003

Posted 18 May 2004 - 11:54 AM

I'll second or third that recomendation. Dr. Clay's stuff is great. But even more important is that you not allow that dew to form on your corrector in the first place. Get a dew shield and or a dew chaser such as the Kendrick system.

#8 Stelios

Stelios

    Fly Me to the Moon

  • *****
  • Moderators
  • Posts: 6518
  • Joined: 04 Oct 2003

Posted 18 May 2004 - 12:53 PM

From http://www.celestron...tm#HOWCANICLEAN :

A: The outside of the corrector plate can be cleaned using a solution of 60% distilled water and 40% isopropyl alcohol with one drop of clear liquid dish soap per quart of solution. The solution is applied to a soft tissue or cotton ball and is carefully rubbed onto the corrector plate using radial strokes from the secondary mirror housing outward. We do not recommend removing the corrector plate. The corrector plate is optically matched to the mirrors in alignment and in rotation. If the inside of the corrector plate or mirrors becomes dirty, call Celestron and arrange to send your telescope in for a thorough cleaning. Celestron offers complete cleaning and collimating services. Contact the Technical Service Department at (310) 328-9560.

#9 Tom L

Tom L

    ISS

  • *****
  • Posts: 31061
  • Joined: 07 Jan 2004

Posted 18 May 2004 - 03:45 PM

Are there special cotton balls out there that don't make a mess of things? Maybe it is the ones that my wife has, but these things literally desintegrate into their constituent threads when I use them (which I don't do any more).

Why are dealers selling the ASO cleaning fluid for SO MUCH MONEY! 2 oz for $12 bucks seems like a lot to me. I still haven't found the fragrence-free dish washer detergent either...

#10 Guest_**DONOTDELETE**_*

Guest_**DONOTDELETE**_*
  • -----
  • topic starter

Posted 18 May 2004 - 04:22 PM

Thanks for the responses guys! I was reading the Arkansas Sky Observatory Site that John posted above and it states to not clean the optical surface unless absolutely necessary.

I have water drop marks all over the lower 1/2 of my optics. Does this count as necessary??

Also, I was told by someone at Creve Couer Camera, who is an authorized Celestron dealer, that you should just use the moisture of your breath and a very soft optical cloth to clean the scope optics and all eyepieces. Is this true??

I somehow doubt that a little breath-fogging of the optics are going to remove these water spots! :undecided:

My Kendrick dew shield should be here tomorrow! Woo Hoo! :D Next inverstment will be the heater.....

#11 Guest_**DONOTDELETE**_*

Guest_**DONOTDELETE**_*
  • -----
  • topic starter

Posted 18 May 2004 - 04:56 PM

If you are bothered by water spots, try saliva spots. Terrible idea! Saliva will destroy some filters and I suspect the same for optical coatings. Don't do it.
Russ Schnitzer

#12 jrcrilly

jrcrilly

    Refractor wienie no more

  • *****
  • Administrators
  • Posts: 35396
  • Joined: 30 Apr 2003

Posted 18 May 2004 - 06:34 PM

I have water drop marks all over the lower 1/2 of my optics. Does this count as necessary??


Yes - those will become permanent if left too long. You can remove them either by abrasion or by dissolving them with a cleaning solution. Abrasion sounds like a really, really bad idea to me. :foreheadslap:

#13 jrcrilly

jrcrilly

    Refractor wienie no more

  • *****
  • Administrators
  • Posts: 35396
  • Joined: 30 Apr 2003

Posted 18 May 2004 - 08:51 PM

Why are dealers selling the ASO cleaning fluid for SO MUCH MONEY! 2 oz for $12 bucks seems like a lot to me. I still haven't found the fragrence-free dish washer detergent either...


I posted the links but with some reluctance; I think the prices are way too high. This isn't laboratory science; takes 15 minutes to whip up a batch. I can tell you that you can skip the photoflow stuff and still get a streak-free result.

I dunno about the cotton balls; I got whatever kind Dr. Sherrod recommended and have not had any debris from them. I'm still using the materials from the initial shopping spree so I'm not sure where I got some of it.

#14 Rusty

Rusty

    ISS

  • *****
  • Posts: 22761
  • Joined: 06 Aug 2003

Posted 18 May 2004 - 09:50 PM

Just make sure you get isopropyl alcohol with NO additives (like aloe). Better is 91%, best is 100% (no water, add your own distilled....).

#15 gazerjim

gazerjim

    Cosmos

  • *****
  • Posts: 8370
  • Joined: 12 Feb 2004

Posted 19 May 2004 - 03:38 AM

My experience w/corrector plate of 9.25: had some kind of mystery gunk that isopropyl alcohol wouldn't touch--probably pollen and pollution. I wound up using a product called ROR (residual oil remover) purchased from camera store. It initially made a mess, but only because "gunk" was dissolving. I went through almost 2 boxes of surgical cotton, but result seems mostly good. I don't trust pre-manufactured cotton balls; just my personal opinion.
Firt rule, of course, is don't clean unless necessary. Defining "necessary" is an issue in itself.
Hope this helps.
Jim

#16 Guest_**DONOTDELETE**_*

Guest_**DONOTDELETE**_*
  • -----
  • topic starter

Posted 19 May 2004 - 07:16 AM

I'm just about to embark on the task of cleaning my corrector plate. It's taken a while to find isopropyl alcohol in the UK, no pharmacists stock it and camera shops only sell the standard lens cleaning solution (which is 70% IPA, 30% tap water and smudges!). However, for those in the UK wanting to source the good stuff you can buy it here in a 1 litre can. It's 99% pure and costs £9.99.

I plan on mixing it with a bit of water from my tumble dryer! It's a condensing tumble dryer which runs the steam through a condensing filter and cools it, collecting the water in a reservoir - this will distill it, right? Please let me know if this is a bad idea but I think it's far better than using tap water!

Jason

#17 Tim2723

Tim2723

    The Moon Guy

  • *****
  • Posts: 5765
  • Joined: 19 Feb 2004

Posted 19 May 2004 - 07:59 AM

Given the importance and necessity of cleaning lenses and corrector plates, and considering that it is something that must be done by the end user, one would think there would be a better concensus of opinion among the manufacturers and suppliers for cleaning procedures. Over the years I have cleaned my lenses hundreds of times using nothing more than a soft lens brush, 70% isopropyl alcohol (plain old rubbing alcohol), and tissue (Kleenex, yes, Kleenex!). I have never managed to scratch a lens or coating. I've never cleaned a mirror at all, except to blow it off with canned air.

I somehow get the feeling that the fear of ruining an expensive bit of glass has given rise to all manner of 'Urban Myth". I really have a hard time believing that any scope manufacturer would coat a lens with something water soluable, since dew, or breath, or just humidity would destroy it; nor something so soft and scratch prone that the wrong kind of cotton ball would lead to disaster. How would anyone stay in business that way? I further get the impression that there are some very pricey cleaners and cleaning kits out there that are sold based on this fear.

I once recommended buying a cheap pair of coated binuculars to practice the cleaning procedure on before attempting the big expensive glass, but I was beaten down pretty badly for that one.

#18 Guest_**DONOTDELETE**_*

Guest_**DONOTDELETE**_*
  • -----
  • topic starter

Posted 19 May 2004 - 09:36 AM

My scope corrector plate looks like it ran through a dishwasher and missed the spot free rinse..... does this sound like it's bad enough to call for a cleaning??

The president of the St. Louis Astronomy Society said that if I don't get the dew spots off in the next day or so, it could cause permenant staining of the corrector. Anyone know about this??

I think maybe Tim 2723 maybe on to something as far as the over cautiousness goes. Why would a telescope maker make coatings and lenses that are sooo sensitive that they can't be cleaned considering the fact that a scope spends it's life outdoors in the dew and dirt?? Doesn't make any sense to me either.

But then again....this is a $2,500.00 scope..... I don't want to take any chances.....

#19 jrcrilly

jrcrilly

    Refractor wienie no more

  • *****
  • Administrators
  • Posts: 35396
  • Joined: 30 Apr 2003

Posted 19 May 2004 - 10:08 AM

if I don't get the dew spots off in the next day or so, it could cause permenant staining of the corrector. Anyone know about this??


I dunno about a day or so, and it depends on just what it was that was suspended or dissolved in the water and subsequently left behind. There is a time which is too long, though, and water spots can definitely become permanent under some conditions.

Best bet is to clean it up and be very careful to avoid another soaking. I clean my correctors whenever I goof and get dew (not very often).

#20 bierbelly

bierbelly

    Voyager 1

  • *****
  • Posts: 11544
  • Joined: 23 Jan 2004

Posted 19 May 2004 - 11:29 AM

Angel,

I wouldn't be too worried, either about permanent staining or about messing up the corrector when cleaning it. It's been my experience that the cleaning process is more of a PITA than an excercise in caution. My problem with my Mak has always been cleaning it, and then later finding that it's still smudged or streaked. Never scratched it. In order to scratch glass, you'll need to rub it with something harder than the glass itself. Certainly cotton balls or tissue paper won't do it. OTOH, you do need to be certain that there isn't any sand/grit that might have blown around and deposited on the surface of the glass, as that would most certainly cause scratching. So the first wash ought to be with plenty of fluid, which will help float any grit off the surface, and with very gentle wiping. Followed by a second cleaning which can be more vigorous.

Cleaning solutions? I've seen suggestions for everything from Windex to acetone. Personally, I'd stay away from anything that has a surfactant (Windex, soaps, dishwashing liquid), since they are really hard to clean off completely (which is why I'm always streaking my corrector plate). I'd try the alcohol solution, which is polar enough to (probably) remove the spots you're seeing, if they are caused by salt, acidic dew or the like, and nonpolar enough to remove oils, sap, etc. (though, if it's sap, you'd be better off with turpentine). The good thing about the alcohol is that it will evaporate off the lens fairly readily, without having to wipe it down like you'd have to do with a water-based solvent/solution.

#21 Tim2723

Tim2723

    The Moon Guy

  • *****
  • Posts: 5765
  • Joined: 19 Feb 2004

Posted 19 May 2004 - 01:05 PM

Other things to stay away from are colorants and perfumes (sometimes added for a less offensive odor), they almost always leave residues and streaks.

My point about using a cheap lens for practice is that cleaning a telescope has a certain mystique about it that makes beginners think it's too difficult or dangerous (because it IS a $2500 scope, after all!). I believe that if one is nervous and jittery, one is most likely to make a mistake. Practice on a $30 binocular will cure the jitters, and $30 is certainly not a lot of money to invest in your education, and you soon realize that your telescope is a machine, not magic.

I just get so angry at manufacturers who sell isopropanol at $300 per gallon with a label that proclaims it "safe for coated optics", which makes the buyer think that somewhere there is another of brand that ISN'T safe for the optics. It's an old marketing trick that still works to empty the pockets of nervous beginners everywhere.

#22 gazerjim

gazerjim

    Cosmos

  • *****
  • Posts: 8370
  • Joined: 12 Feb 2004

Posted 19 May 2004 - 03:21 PM

I agree wholeheartedly that the issue of cleaning fine optics has been sidestepped by the industry overall. Maybe for liability reasons? Orion sells a small kit that is adequate for eyepieces, but not up to corrector plates. Tried to find a pint of reagent grade grain alcohol in Austin (population about 1,000,000). Nobody had it in stock--hazmat fee for special order shipping was about 20 bucks.

#23 Tim2723

Tim2723

    The Moon Guy

  • *****
  • Posts: 5765
  • Joined: 19 Feb 2004

Posted 19 May 2004 - 04:16 PM

Reagent grade is tough to get. The best I've found is 92% at my drugstore (technical grade). If you're willing to try ethanol instead of isopropanol, you might find a product called "Everclear" in your liquor store - 180 proof grain alcohol - and very clean and well filtered.

Seriously.

I'm not kidding.

You have to be careful or you start seeing double stars everywhere.

I'm still not kidding.

#24 Guest_**DONOTDELETE**_*

Guest_**DONOTDELETE**_*
  • -----
  • topic starter

Posted 19 May 2004 - 04:58 PM

Thanks a bunch for all your advise and suggestions. I'm going to go to the pharmacy tonight and get some alcohol and mix it in a spray bottle with distilled water and use that (sans the dishsoap) and get somekind of soft cotton balls or kleenex and VERY gently clean it.

Hopefully this won't happen again......(wishful thinking)

#25 Don W

Don W

    demi-god

  • *****
  • Administrators
  • Posts: 22392
  • Joined: 19 May 2003

Posted 19 May 2004 - 05:20 PM

Get sterile cotton balls.


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics