POLLEN AND YOUR TELESCOPE - Preventing Optical DamageBy
P. Clay Sherrod, Arkansas Sky Observatories
Every mid-spring I start getting inquiries about POLLEN and its affect on coated optics and so it is well worth a reminder here: I believe that the best (and it is tried and true....) method to remove pollen is the procedure that I have ldescribed at the Arkansas Sky Observatories website:
This will cut right through pollen and sap...you are very much correct: there are considerable amounts of sap in every granule of pollen...that and the abrasive burrs are what allows the pollen to stick to its intended surfaces.
Pollen is one of the most destructive things that will get on the corrector plate and should be treated as such. All one has to do is to look at a pollen grain under a microscope to see how incredible abrasive it can be on coated surfaces....Protect Your Investment from the #1 Most Damaging Substance
We all have problems with pollen irritations in the springtime. Pollen is a pesky little package that - under a microscope - looks like something from the movie "Alien." The same factors that cause human irritations through pollen (itchy eyes, swollen nasal passages, inflamed glands....) are responsible for POLLEN to be the NUMBER ONE most damaging factor of telescope lenses, corrector plates and mirrors.
Right now, the pollen counts throughout the United States have been off the scale due to the unusual climatic conditions of the previous summer and winter. Don't look for things to level out anytime soon, either, as other pollens throughout late spring and early summer will merely replace those we are dealing with right now.
Pollen collection on your telescope surfaces will happen whether or not the wind is blowing; the pollen is so lightweight it is easily transported throughout the air; the only remedy is a good rain shower to cleanse the surrounding air, but that is only a temporary fix as the pollination procedure progresses.
Consider the following:
1) Pollen is abrasive - it varies, but most pollen grains have "spicules" (or spikes) that protrude like sharp points so that they may adhere to surfaces (such as the wings of a bumble bee); other types have "knobs" which serve the same purpose....there is even a "Velcro pollen" which attaches itself via a "hook" type extrusion to soft surfaces like the hair of a bee or the feathers of a bird.
2) Pollen is coated with a sticky emulsion, like the consistency of honey, that intentionally is there to act as a "bandaid" to get it to stick to ANYTHING that it comes in contact with.
3) Combine the two above, and you have ONE MEAN CRITTER if it gets on your mirrors, Maksutov lens or corrector plate of your expensive telescope. DO NOT ATTEMPT TO REMOVE UNTIL YOU HAVE READ THROUGH THIS THOROUGHLY!!
Attempting to remove pollen from the wonderfully-coated glass of our telescopes can be the most damaging and irritating thing that you can do to the telescope.
Merely "cleaning", even if you use the right techniques and solutions, will do nothing more that "grind" the pitch-fork spicules into the deep coatings....it is like using steel wool on your corrector plate. YES, it really is.....and pollen is sappy and it will smear when cleaned improperly, simply making things worse.
PLEASE follow the guidelines I have outlined below to protect your investment during this time of massive pollen production....this is NOT dust, folks...it is NOT dew nor fingerprints. It is POLLEN, and it can strike a death blow to your optics if not removed early, and removed properly!
1) protect the telescope from pollen during observing: either use a dew shield while your lens cap is off, or put the cap ON when you have extended periods between "looks;" during the spring of year, you can have a one-component layer of pollen across your corrector plate within 5-7 minutes unprotected;
2) make sure to GET THE POLLEN OFF immediately upon coming in for the night; if you allow the adhesive to dry onto your corrector plate, chances are you MAY not get some of it off; this is particularly true if you allow it to remain on during the hot summer months;
3) carefully remove the pollen and clean per the EXACT STEPS following. NEVER simply clean the lens....always follow these guides when it comes to pollen.
DR. CLAY'S DE-POLLINATOR (patent pending.....not really)
As soon as you are finished observing and the scope is indoors away from open screened windows or doors, remove the lens cap in a darkened room; look at the lens or corrector plate with a flashlight held obliquely (looking across lengthwise) the glass and see all the pollen. You must get that stuff off before it dries and sticks to the glass surface more permanently. Pollen sap remains fluid for a very short period of time and removing will leaves streaks if not done properly. However, once the sap solidifies, it is very much like dried shellac and can be nearly impossible to remove the pollen grains from the dried sap.
1) I use a medium-firm flat-edged artist's camelhair paintbrush that is 1" across to loosen particles of dust and pollen from the corrector plate. DO NOT RUB with the brush, merely very gently LOOSEN and fleck off all that you can....some likely will NOT come off in this step. Some will smear across the glass.
2) Once you have done that, use some "canned air" to blow off the loosened particles. CAUTION: You must be careful using compressed air cans on your optics, and some people never tell you this. Be sure to:
a) NEVER shake the can; this stirs up the propellant and causes condensation to form which will blow water droplets all over your optics;
b) NEVER assume that the canned air will get the particles off without BRUSHING FIRST....if you don't brush, well, your optics will be toast;
c) use the canned air only in SHORT bursts, not a continuous stream, as long cycles will result in cooling of the propellant inside the can and result in liquified substances spraying onto your optics.
3) Now, use the optical cleaning solution and procedure described at: http://arksky.org/aso/aso-guides/aso-general-guides/23-aso-fine-optics-cleaning-system
Kleenex tissues work just fine for this cleaning, provided that you do not "over-use" any one tissue until it becomes limp and begins to shed particles or tiny shreds of paper. Never use scented tissues or those with "softening agents"....only pure white, non-fancy Kleenex brand. NEVER RUB OPTICS WITH DRY TISSUE prior to complete cleaning!
4) Daub the solution sparingly, but enough to wet the surface, without any rubbing at all at this point; this step is to further loosen particles and to begin to break down the tiny stains left by the pollen adhesives....YES, they will still be there.
5) Once the entire glass surface has been daubed down, USING THE SAME KLEENEX, very, very gently begin to wipe (not rub) in a slow circular motion, making sure that any particular area does not become dry at this point. Keep the glass WET at all times....do not allow time to dry.
6) Now that you have wiped the entire surface, get a FRESH Kleenex or two and apply a generous amount of solution TO THE KLEENEX (never to the optical surface) and very gently begin rubbing in similar circular motions, but GO BACKWARDS from step 5); you are actually allowing the detergent to clean off the pollen goo.
7) Repeat with a plenty of fresh Kleenexes, but rub even lighter, just smear some cleaning solution across the glass.
8) With a fresh Kleenex (actually several) that has been "Misted" with pure distilled water (not wet at all, just moist), begin to "buff" every-so-lightly about 1/4 of the area of your glass at a time; if you see stubborn stains, or still some pollen debris, merely get another Kleenex and gently rub those areas to remove. Continue until the entire surface has been done.
9) NOW, take a bunch of Kleenex and use TWO at a time (so that the oils in your fingers do not penetrate to the glass) and dry-buff with the lightest possible touch, just like on a vintage automobile. Do this step twice to remove any streaking. Never let the same surface of the Kleenex rub across the buffing surface twice....tissue is cheap. OPTICS are not.
The alcohol is there in part as a drying agent. NEVER use more than a 3:1 ratio of water-to-alcohol, as this can dull your coatings. In the proper solution this cleaner is entirely safe and excellent for you glass and its coatings.
REMEMBER....as in so many things, prevention is always better and easier than the cure. Protect your optics when you are outdoors. On my portable telescopes I use a pillowcase or cotton sheet and place over the entire telescope when it sits idle for very long on pollen-laden spring nights. I merely remove prior to putting my eye up to the scope each time.
Sound like a lot of trouble?? So is replacing the SINGLE-MOST-EXPENSIVE piece on the telescope.