Re: (ATMoB:Discuss) Dirty 2" TV Everbrite Diag

Gary,

If you can remove the diagonal from its' mount, it would be best to submerge it in Ivory Liquid Detergent in warm distilled or DI water. 2-3 drops of detergent are sufficient. Rock the mirror around a few times to loosen the dust and grit. Use a cotton ball and drag it across the mirror in circular strokes and NO pressure. Rinse in DI water and pat dry with lens tissue. I use canned air to speed the drying.

If the base reflector is Silver, there may be small black pits of corrosion. Do not try to remove! They will only get worse.

If the surface still looks oily, flush with pure acetone with a polyethylene wash bottle. If the mirror is still warm, the acetone should dry without a mark. Residual aerosols will leave stain. In that case, try repeating the detergent process.

The problem with cleaning with swabs while the mirror is still mounted is that you will start dragging grit across the surface and cause many micro-scratches.

I have attached an ASCII text file with much more detail.

Paul V.

----- Original Message -----

From: gary_a_weston*at*us.ibm dot com

To: atmob-discuss*at*atmob daht org

Sent: Thursday, August 29, 2002 10:20 AM

Subject: (ATMoB:Discuss) Dirty 2" TV Everbrite Diag

Hi,

It looks as if the diag mirror on my everbrite is in serious need of cleaning. Anyone have a good method for doing this? Its not simply some dust on the surface. I guess over time this thing has collected a good amount of grime. I can notice the degredation, as some stars seem to get blurry and smeared in certain areas. My guess was maybe using cotton swabs and 90+% alcohol. As i've never cleaned it before, I wanted to make sure I didn't do anything wrong and ruin it.

Gary

CLEANING PROCEDURES for OPTICAL COMPONENTS By Paul A. Valleli V.2 May 26,1996 1. SCOPE This procedure is a general purpose method for cleaning aluminized telescope mirrors and some other optical elements up to an aperture of about 18 inches in diameter. 2. CLEANING MATERIALS AND EQUIPMENT Surfactant Cleaner, one of the following: ORVUS, Hubbard - Hall, Waterbury, CT, 1/8th tsp/gallon (Sodium Lauryl Phosphate) Ivory Liquid, Proctor & Gamble. Cincinnati,OH 45202 - 3 oz. per gallon of water, or any equivalent brand of neutral dishwashing liquid Mir-O-len Cleaning solution. Dudley Leroy Clausing Co. 8038 Monticello Drive, Skokie IL 60076. For very severe contamination: L O C (Liquid Organic Cleaner), Amway Corp., Ada, MI - used full strength. Mr. Clean, Proctor & Gamble. Cincinnati, OH 5202 - used full strength (heavy duty cleaning). (Strong alkali - not for aluminized surfaces). WBS Solvent,Goldenwest Mfg. Co. Cedar Ridge, CA 95924 - use as directed, 1:3 to 1:8 dilution Distilled or deionized water, or filtered tap water as a minimum; with Sink or Catch Basin. Plastic Dishpan, basin, or container that is large enough to submerge the mirror Acetone, reagent grade preferred -Optional. Isopropyl or Methyl Alcohol, reagent grade. Sterile Cotton Balls or wadding Tissue, wiping; such as: Lens tissue, Aldine #51 (AE202). Aldine Paper Co., 315 Park Ave. So., New York, NY 10010. KAYDRY Tissue wipes, Kimberly - Clark Corp., Roswell, GA. Kleenex Tissue, Kimberly - Clark. Air gun supplied with dry, filtered (.5 micron) Nitrogen regulated at 15 psi maximum - optional. Negatively Ionized Air Gun or Blower - optional. High-intensity lamp - AO Reichert or equivalent. A flashlight can work well for before, during, and after cleaning inspections. Safety waste can for flammable materials - optional. Rubber Gloves or finger cots, unpowdered - Optional NOTE: Optional items are intended for cases where an extraordinary or difficult cleaning task is encountered. 3. PROCEDURE If preferred, brush away any loose particles, first. Otherwise, flush all the surfaces of the component with filtered water at a glancing angle before starting any cleaning. This will remove most loose particles. Set the mirror in a basin of warm water, about 100F - 120F, and liquid detergent. Allow to set for one-half hour. Rinse the component to remove all detergent. Bad smudges may require the local application of a full strength detergent. Soak and flush again, thoroughly. The idea is to try to release as much entrained grit as possible, without rubbing. Set the component aside and refresh the detergent in the basin. Soak the component again. This time, with a light, circular motion, wipe the surface with a large swab of cotton. Use only the weight of the swab. Start at the center of the component and work outward toward the edge. If the part is perforated or has indentations, it may be necessary to clean them out with a swab or Q-tip first. At this point, the flush should be followed with a secondary flush of distilled water. Set the component up on edge and examine it carefully. The water may run off in beads, leaving an oily film or spots that were not broken down by the detergent. Rinse the component while it is on edge with acetone from the wash bottle. Catch the runoff in a pan or tissue. Next, it may be desirable to follow with an alcohol rinse from another wash bottle and then swab with a cotton wad. Now finish with another flush of acetone. If the mirror is still warm and the acetone very pure, the last traces of acetone may evaporate in a flash and leave a pristine surface. More than likely, however, the oily spots or film may have been covering and protecting water marks or stains. After the solvent rinse, these areas will now respond to the detergent soak. Repeat it again, then flush with pure water, then acetone. In the majority of cases, this four-stage cleaning cycle of flush- detergent soak-flush, solvent flush, detergent soak-flush, solvent flush, will remove a many tiered layer of aerosols, water marks, and oil films that result from outdoor exposure. In some cases, the water rinse will be good enough, with no beading effect. This is a water-break free surface and indicates a pretty clean surface. The mirror can be set on edge to dry and excess water blotted from the bottom edge with tissue. Dry filtered nitrogen could be used at this stage to accelerate the drying before dust and lint begins to cling to the wet surface. On occasion, really stubborn spots may be caused by drops of pine tar, asphalt, soot, or spit droplets being baked onto the surface. The only recourse is to attack these areas with local pressure from a cotton swab. Remember the multi-layer effect, and alternate solvents, do not keep scrubbing away with just one system. More powerful solvents such as Methyl Ethyl Ketone, may be needed. 4. TECHNICAL COMMENTARY There are many various optical cleaning chemicals and procedures, some of which may work just as well as this described method. A few may work better, but some are un-satisfactory. All depend on the skill of the person doing the cleaning, the type of optical component, and the nature of the contamination. Understanding the multilayer nature of atmospheric contamination can minimize the number of cleaning stages. It is important to remember that any form of wiping or mechanical rubbing on a dirty surface will cause some amount of scratching to an optical surface, depending on the hardness of the contamination. The contamination may be on the surface, on the wiper, or in the cleaning solution. The light scatter or the degradation caused by surface contamination must be weighed against the possibility that greater harm may come from the cleaning process. Also, some cleaning procedures may be inadequate because new surface contamination is left or other surface damage occurs. Silicone grease is a particularly difficult compound to deal with. Growths of Fungi must be stopped because an acid residue that can etch the glass. "Simple Green" enzyme detergent seems to destroy the growths. 5. Precautions. Some general precautions should be taken to achieve and maintain a high quality surface finish: a. Avoid unnecessary exposure of optical components to a contaminating atmosphere. Use lens covers and maintain low humidity. b. Wash hands thoroughly and scrub fingernails before handling optical components. c. Wear plastic/rubber gloves or finger cots whenever feasible. d. Do not make major changes to a recommended cleaning procedure. e. Never re-use a sheet of lens tissue or an old wipe that might be contaminated with grit or grease. g. Never use toilet tissue for cleaning, it may have an unacceptable amount of abrasive silica dust. h. Be very careful with the use of canned air or Freon "Dust-Off," it may leave moisture stains if the can is shaken during spraying. i. Washing or wiping with precipitated chalk powder or rouge may cause hairline scratches. (Some coating labs do this.) Use only with great care, when necessary. j. Use a smooth wiping motion with minimum pressure when cleaning. Never use a "scrubbing" motion because this may damage the surface being cleaned. k. Use care to avoid contamination of the cleaning solutions. Use polypropylene wash bottles fitted with a nozzle. l. Brushing a component with a soft, camels' hair brush can remove loose specks of dust and lint. However, this technique could drag abrasive particles across the surface and cause scratches. Also, it might tend to leave grease streaks, unless cleaned in a vapor degreaser. m. After opening, store the facial, wiping, or lens tissue box in a clean plastic bag to prevent contamination. CAUTION WHEN USING FLAMMABLE SOLVENTS, BEWARE OF OPEN FLAMES AND EXPLOSIVE CONDITIONS. 6. PREPARATIONS Prior to cleaning the optical component, the area should be organized and all unneeded equipment and tooling should be removed from the area. The cleaning materials should be placed conveniently at hand. Remove pens, pencils and rulers from uniform shirt pockets, as well as jewelry and watches. They could drop on the optical surface or scrape it. Thoroughly clean dishpans and basins prior to using. Optics should only be cleaned when the instrument performance is significantly impaired. Never try to wipe a dry polished surface with a dry material. It will most likely act like sandpaper, dragging grit across the surface and cause scratches. Always examine the optical surface and edges prior to cleaning for loose chips of glass on the perimeter or gross contaminants on the surface. Change to new swabs frequently Constantly replace saturated tissues until the surface is completely clean and dry. Inspect the surface under the high-intensity lamp to be sure there is no residue. Very little pressure should be used during the wiping process. Cover workpiece with special protective cap or with lens tissue and a layer of plastic foam. 7. PROLONGED STORAGE OF AN OPTICAL COMPONENT: Materials Required: Opticlean Strippable Coating, Bradford Labs.,Mountain View, CA 94013-1002 3M Scotchclad #2253 (hard to obtain) New, soft paint roller Paint roller tray, disposable Remove any gross contamination, fingerprints, oil Surface must be dry Apply strippable coating with paint roller to optical surface and allow to dry thoroughly in a low-humidity area. Do not attempt to force-dry with a heat lamp or heat gun, staining may result. OPTION FOR SMALL ELEMENTS - apply with clean, new, soft paintbrush or Kaydry dipped in the Opticlean 8. NOTICE: Reference to company names or products in this document does not imply exclusive approval or recommendation of the product. Other products may be just as suitable. Also, satisfactory results might not be obtained in certain specific applications.

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