Mirror Cleaning with Collodian USP

After having run across several articles on using collodian USP for cleaning optics I decided I had to give it a try.  

An excellent article on this technique is at:   http://www.rhinodev.com/oldscope/atspages/techtips.htm

I purchased a 500ml bottle of it for $45 from General Laboratory Supply, Inc.,  2835 Preston Road, Pasadena, TX 77503    (281) 487-0633  (They only sell wholesale)

Its made by Mallinckrodt, and is referred to as "Collodian USP"  Do NOT get "Flexible Collodian", which is used in the medical community.  It will leave an oily residue.

After returning from the Texas Star Party, where it is REALLY dusty, my primary was in TERRIBLE shape as shown in the image below!

(Click on the photo to see a larger image)

The image above is my primary in its mirror cell.  Note the fact you can only see the reflections of the tree limbs in the mirror as blurred shadows (this helps explain the lower than expected quality of my ccd images at TSP!!! At least I have an excuse!!)

After cleaning the mirror, all I can say is  Wow!  Does it work well!!!  Really easy, no mess.  A bit dangerous since its ether based (do it outside), but other than that, for mirrors not easily washed with water/alcohol or for eyepieces with fingerprints on them, its a really good option!  The following series of pictures and text will show you what I did......

I put one thin coat on, using a soft brush (I got a "Hake" (wide, thin, soft, cheap) brush from Texas Art Supply for $1.28).  It turns into something like Saran Wrap after a few minutes.  The brush is not cleanable afterwards since it is full of "Saran wrap".

(Click on the photo to see a larger image)


I then laid cheesecloth on it and put two more coats on it.  The cheesecloth is to help hold the film of collodian together when it is removed.

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When the edges started to peel (after about 5 minutes) I simply slowly peeled it off the primary.......  I  now have a Saran Wrap/Cheesecloth composite with dirt on one side, and a clean mirror (compare the reflections with the first picture!).  I did learn something though, I took my mirror from a/c inside to hot and humid outside.  I obviously did not wait long enough for the mirror to warm up since when I peeled off the collodian there was condensate under it (you can see it on the mirror in the picture below).  It quickly evaporated, but........    I may try another treatment with the mirror at ambient to see what will happen.  If you use it on eyepieces or secondary mirrors, Gary Seronik (S&T magazine) cautions about getting it on painted or anodized surfaces, since it really likes to adhere to them.  It comes right of the mirror though

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The finished mirror now shows its very poor and in need of replacement coating, but its CLEAN!!!!!!!!!! Compare the reflections in the mirror in the following picture to those in the first one!  (Sure wish I had taken the bottle of collodian to TSP and used it before I tried imaging the very dim Cocoon Nebula!!).  The very poor condition of my coating had caused me to NOT try it before TSP (no coating would have been the only thing worse than the dust!!), but my fears were unfounded......it came right off the mirror surface with not hint of damage to what is left of the coating...  It has not looked this good in years!

(Click on the photo to see a larger image)

After I reported my experiences with collodian USP on the ATM E-mail listserver,  Larry Arnold posted the following note about another product for cleaning optics:.    

"  I had a hard time locating someone who'd sell me collodian. As Brian mentions, it's now regarded as a hazardous material & the local pharmacists didn't wanna be bothered.

Then, about 2 months ago, there was a brief thread here about "blue spray" for cleaning mirrors. I managed to track this stuff down and bought some. It works as well as I've heard collodian works and it's easier to apply, in my opinion. It comes in a spray can, so you just spray-paint it on the surface of your mirror. I did a couple of mirrors with it. One, I applied 2 thin coats, the other 1 heavy coat. Results were the same in both cases. The stuff dried quickly, leaving a soft, pliable membrane (bright blue!) on the mirror. I used a tab of masking tape to lift it up off the edge of the mirror and peeled it away. It came off easily in a sheet, taking the dust & grime with it off the face of the mirror. There was no apparent residue & the mirrors were clean. I protected the edge of the mirrors with duct tape before spraying them. Here's the info on the product and the people who sell it:

Universal Photonics Inc.
495 West John Street
Hicksville, NY 11801 USA
Ph: (516) 935-4000
FAX: (516) 935-4039
Sales (800) 645-7173

Part number LB0004
PRE-COTE 33 BLUE SPRAY protective coating
$13.65 US per can
$20.00 US minimum order

A can will cover approx 300 square inches, according to the customer service girl I spoke with. They offer the product as a protective coating for lenses. She said opticians use it.

Note: this product will remove dust and loose particles on the surface of the mirror, but it will not remove spots or stains or anything caused by liquid or moisture on the surface.

Usual disclaimer... I don't have any connection with this company or their products. I don't own any of their stock and none of my relatives work there. I like the results I get from the product. You may not. Not my fault...    Larry"

Since I only used about 1/5 of the 500ml bottle on my 14.5" mirror,  I will certainly not be needing this "Blue Spray" for a while, but for folks that have a difficult time getting collodian USP, it might be a good alternative to having to remove your optics and perform the more conventional (and also very effective) cleaning by spraying on or soaking in a mixture of  60% distilled water/40% denatured alcohol/a drop of dishwashing soap and then using a leaf blower to blow it off (which is the way I used to do it).  Some systems will allow you to do this with the mirror still in place, which decreases the collodian or blue spray's advantage, but the water/alcohol approach I have used for years NEVER cleaned my mirror as well as did the collodian.

I also do not advocate "Over cleaning" optics, since a "little" dust is not a problem (TSP dust was a major problem!).  Also, this collodian USP is pretty nasty stuff.  read the safety data sheet that comes with it and use it away from any ignition sources.  Its fumes are intoxicating and flammable (ether), so I recommend doing it outside (let your optics warm up though!).   Since its dangerous stuff if misused, I, like in Larry's note, have to say you are on your own and I take no responsibility (sad society that we have when I have to end with that, eh?) but I do like the results and will continue to use it on my eyepieces and optics......  


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