Bird droppings, rainwater infiltration, and stormy weather can obscure the optical surfaces of your refractor telescope. It is best to avoid objects that can damage your valuable instrument. For example, avoid leaving it in freezing temperatures for any period.
However, if your telescope falls or is struck and your lens is damaged, I recommend using a thin cloth or a clean, soft disposable cosmetic face napkin.
Refractor Telescope Maintenance
No chemicals should be used to erode metallic engineering and groove on the glass surface. The most severe problem with cleaning your home telescope occurs when you touch the mirrors or lenses with your hand. Did you know that every human fingerprint contains more than 10 million bacteria?
That dirt will stick to your optics and even scratch them!
Anything that sticks to your electronics, such as tape or adhesive-backed deposits, has the potential to shred the thin film used in the laminate stages of these components. So clean out heat sink debris, dust, insects, spider silk, and other tangled strings before touching the primary mirror or disk with your bare hands.
As for additional equipment, you will only need a commercial telescope cleaning kit and lots of cotton wool buds. The material must be suitable for precision instruments, such as optical mirrors and cases, lenses, and prisms because it is possible that particles could scratch the protective layers that are on these components.
Sunlight is often harsh for containing many invisible ultraviolet rays, so avoid using ordinary bathroom cleaners.
How to clean telescope mirror
To clean away any contamination, first use a skinny brush like one used for computer screens as well as q-tips to remove dust, dirt, and other debris from around your lenses.
Then apply the cleaner, and a small soft cloth or a lens tissue assist in completing the task.
If a jar of cleaner is taped shut, take extreme care when opening it if fingers touch the edges.
If your eyepieces become dirty, you can do the same process by sticking on the end of an old CD leftover wipe the dust off with a lint-free pad then a blower card to get rid of it.
How To clean Telescope Filters at Home?
When taking out circular(flat) filters, make sure when peeling any odd deposits that even the edge of the sticky tape does not come up into the threads of your filter. Soak beforehand if necessary by gently placing the exposed filter material in warm linens soaked in water, then remove gently dabbing thoroughly with soft fabric that absorbs the moisture. However, most probably, your filter is already washed.
Alternatively, use a business-supplied de-ionized or distilled water instead. You can also try cleaning with a light spray of Isopropyl Alcohol. But NOT diethyl ether or amyl alcohols!
If you are unsure that you will be able to clean telescopes at home, you should seek a telescope cleaning and repair service near you.
I hope this answer helps you.