Arkansas Sky Observatory Cleaning Fluids & Spritzer Bottles
ASO bottles Isopropanol bottle
ASO Cleaning Solutions

ASO Isopropanol Spritzer Bottles (shipped empty)

*2 oz cleaner/ 2 oz rinse $14
2 oz bottle $4
*4 oz cleaner/ 2 oz rinse $19
4 oz bottle $5
  4 oz cleaner/ 4 oz rinse $24

  4 oz cleaning solution refill (no spritzer) $12

* size available in the Pegasus Cleaning Kit

All prices include US shipping

"invented by an Astronomer, prepared by a Chemist"

        The Arkansas Sky Observatory’s Dr. P. Clay Sherrod has produced on its webpage an excellent guide for cleaning your eyepieces and other refractive glass (corrector plates, etc). He recommends making your own excellent quality cleaning solution and rinse solution. A pamphlet with his guide is available as a pdf file. Dr. Sherrod designed this cleaner with the Meade UHTC coatings and the Celestron XLT coatings in mind.  Note that there is now a link in that guide to Dr. Sherrod's method for cleaning 1st surface mirrors.

    There are some wild claims on the internet about eyepiece/refractive surface cleaners. 

-->A few folks use acetone...which will remove your paint and any adhesives holding your lenses together along with the dirt. Don't do it!!!!

--> Some folks recommend lots of alcohol...and that will loosen any adhesives in the area too.  Don't do it!!!!

--> Straight Windex has a pH of 10-11 due to the presence of ammonia which will wreck your coatings.   Don't use it !!!!

--> A lot of the $3.50 cleaners are similar to ours, but stored in polyethylene or polypropylene.  These plastics are know to be permeable to alcohols, but not water.  Check the weight of your container every week and you will see it getting lighter as your isopropanol or other alcohol leaves through the sides of the container.  If you buy this, be sure to use it quickly...   We store ours in polyethylene terephthalate, a more expensive bottle but not permeable to alcohols.

-->  The fact is Dr. Clay Sherrod knew what he was doing.  There is just enough windex in his formula to get the benefits of the formula while keeping the pH at 8.  It has enough isopropanol (some from the Windex) and some added to clean the glass without hurting anything else.  Dr. John Duchek (me) came along and found the proper storage to make the alcohol and other ingredients stay in the container.  I filter all of the ingredients, mix them and refilter them into the individual bottles.

--> One company that sell a similar cleaner is proud to use 99% isopropanol.  That sounds nice, but you don't how it was processed.  The great thing about the 91% material is that the final step in purification is VERY LIKELY to be distillation.  The 91% isopropanol 9% water is what chemists call an azeotropic mixture.  If you do a careful distillation, it is the ratio you get no matter what the ratio of water/isopropanol is when you start.  Having the final step be distillation is very comforting because that means everything in the mixture is volatile.  When the mix evaporates, there is nothing left behind.  If you are cleaning lenses, that is a good ingredient!  In processing we do take the 9% water into account so that the concentrations in the cleaner are correct.

For all of these reasons, we are proud to say, "invented by an Astronomer, prepared by a Chemist"

Here is the value I add to this product:

  • 1. The containers have been tested for compatibility with the formula. There are problems with containers of polyethylene and polypropylene. These are permeable to isopropanol and with time the alcohol leaves and the water stays...and the formula changes.The bottles (polyethylene terephthalate --PET) and spritzers I use have been tested and lose very little material over long periods of time. PET bottles are more expensive than polyethylene ones. 
  • 2. My version of Clay's formula is filtered twice using Whatman grade 541 laboratory filter paper. This has 19-25 micron pores which are quite a bit finer than the "coffee filters" recommended on Clay's site. The bulk solutions are filtered once, and the final product is filtered into the bottle. That coupled with an initial filter paper cleaning step ensures that very few "floaters" (loose fiber from the filter paper) appear in my product.
  • 3. Rather than mixing one ounce of this and one-half ounce of that, I converted the formula to metric and measure the ingredients to a single milliliter (1/30 ounce). After my formula was passed by Dr. Sherrod to be certain I had it right, this accuracy and precision and a specific gravity test on each batch ensures that your bottle is just like the bottles that Clay approved.

Does the brand you are buying tell you how it is processed?

The ASO cleaner/rinse is a great formula when made and stored correctly.  It is the right stuff to clean your eyepieces and refractive glass.  It IS NOT the right stuff for cleaning mirrors.  For that you should use straight isopropanol. 

A user suggests:
ne of my ASO users said that he would like to get a spritzer bottle to apply the 91+% isopropanol to some filters with mirror like coatings that he wanted to clean. That seemed like a reasonable idea for an additional product, so I sent him one free as a thank you for the idea.  The spritzer bottle is the same PET plastic and spritzer head labeled for isopropanol use.

User comments!

For information on the proper use of this product and for methods for properly cleaning 1st surface mirrors, see The Arkansas Sky Observatory (ASO) webpage:

Disclaimer: The Arkansas Sky Observatory Cleaning and Rinse solutions are guaranteed to be prepared in the manner specified in the document above with the exception that high quality laboratory grade filter paper is used rather than coffee filters. Eyepiece/refractive glass cleaning not only require a high quality cleaner, but also appropriate pads and wipes and due care and diligence by the person doing the cleaning. Duchek Consulting Services has no control over your cleaning effort and cannot be responsible for your results. Our guarantee relates only to the proper preparation of these solutions, and our liability is limited to the replacement of the cleaning and rinse fluids or refund of the purchase price of our product.

John Duchek Ph.D.
last update: 2013-0623