I wouldn't worry too much about it. I mean, sure, we should be careful how we clean our optics, but... just shine a strong enough light source through any optical system arriving directly from the factory, and you will see seemingly horrifying sleeks and imperfections on more or less all of the optical surfaces. If you don't see any imperfections, you are (1) either not using a strong enough light source, (2) not pointing the light source at the correct angle or (3) not looking carefully enough. If you still don't see anything, just shine the torch through the telescope from the focuser end, and you will be convinced that I'm right.
I know, I know, we want to believe the precious optics we just bought with our hard-earned money will last for virtual eternity to be passed down through generations, but after I've owned maybe a dozen telescopes I'm realizing that we're not really buying telescopes, but we're really instead buying the enjoyment of owning a scope for however long time the telescope lasts or however long our interest in the scope lasts (which is incidentally usually much shorter than the scope's own useful lifetime). Our scope will get bumps, paint scratches and nicks from handling in the darkness under the stars, and it will eventually get polishing sleeks from cleaning or coating damage from not removing aggressive contaminants quickly enough. We're risking damaging the optics if we clean them and we are risking that harmful contaminant damage the optics if we don't clean them. We expose our optics to air pollution, pollen, falling dew and microscopic rain drops, all facilitating growth of lens fungus. We expose the paint on our telescopes, mounts and tripods to light (which eventually causes bleaching of paint) and dust particles if we decide to always keep a grab-and-go telescope ready for use instead of meticulously packing it down into storage boxes after each use. And if we keep our optics in a home or area with a frequently used fireplace or in a home with tobacco smoke, we expose all surfaces of all your belongings, including our precious telescopes, to substantial microscopic particle pollution (which causes about just as bad or even worse particle pollution than living near a large road intersection). For instance, mechanical clocks are mostly out of fashion today, but years ago it seemed to be common knowledge that the lifetime of mechanical clocks was substantially shorter in smoking homes or homes with fireplaces than in clean home environments.
My point is: I wouldn't worry too much about it. Nothing lasts forever, and I think it's better to consider the telescope as I would a new car. Sure, I don't want paint scratches and dents, but if the car stays parked in the garage under a tarp all the time, I'm are essentially wasting all the money I spent on it. So, I try to keep the eyepieces clean at all times, and I keep the main telescope optics reasonably clean, cleaning them about once or twice per year (living in a coastal climate with moderate pollen and air pollution). And I keep in mind my own eyes are slowly degrading too... I'm pretty sure my own eyes will degrade more in the next 25 years than a reasonably well-maintained telescope would in the same timeframe. Not being an alarmist, but just trying to keep things in perspective.
The first evidence of damage to our scope, self inflicted, accidental or through inevitable wear and tear, can actually be a bitter-sweet blessing: It allows us to stop worrying about keeping our scope in mint condition, and instead permits us to concentrate on enjoying what the scope can show us as a powerful tool rather than optical jewelry.
Enjoy your scope!
Edited by db2005, 21 July 2019 - 01:22 PM.