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5 Easiest Steps to Clean Your Telescope Mirror

You might be interested in observing the night sky or anything of your dream through your telescope. But if you aren't enjoying it because of your dusty telescope mirror, you are really missing it. It is very important to have a clear view through the telescope mirror to see the best sight of the night sky and other objects.

The main way to keep a telescope mirror far from dirt is to be careful in keeping it more protective. When you don't use the telescope, put a cap on the mirror and try to store the telescope in a box or cupboard so it does not get dirty.

If there is any dirt in the telescope mirror and it is not cleaned, the dirt is likely to spread slowly around the mirror. And, if the stain is too dark, the chances of further damage increase.

So if your concern is how you will clean the mirror of your telescope if it gets dirty, we would like to say that nothing to worry about. Every telescope mirror gets dirty. You can easily clean it. No matter what telescope you use for astronomy, you can simply keep the mirror clean and take the best care. Here is a detailed discussion for you. Let's go through.

How to Clean Your Telescope Mirror?

How to Clean Your Telescope Mirror

You can clean the telescope mirror very well with water and a little detergent. Before cleaning the telescope mirror, first make sure that you can remove the mirror from the telescope and put it back on.

You can brush lightly with a camel hair brush to remove dust. And find this brush in the shop from where you bought the telescope or at any camera shop.

brushing lightly with a camel hair brush to remove dust

Various solutions for cleaning hard dirt or stains from telescope mirrors are available online or offline. For example, the telescope mirrors can be cleaned with isopropyl alcohol or methyl alcohol (methanol). These are usually found in hardware stores.

However, if you clean it using alcohol, you may get stains again. So don't forget to clean properly so that there's no stain left and care should be taken to avoid any damage to the mirror surface while cleaning. It is best not to use any chemicals or corrosive substances for better cleaning.

So let's learn how to clean a telescope mirror with water and mild detergent without using chemicals or corrosive substances.

Tools you need to clean a telescope

i) Two towels;
ii) Distilled water;
iii) High-grade cotton wool;
iv) Screwdriver, Allen keys and pen;
v) Tepid water;
vi) Liquid detergent;
vii) Plastic bowl;
viii) Rack;
ix) Kitchen sink.

Cleaning Procedure

Let's come to the point. You have already known what materials you need. Now the question may arise in your mind “how can I use these tools and apply those to clean a telescope mirror?” Just follow the instructions step-by-step process given below of cleaning a telescope with the materials.

Step 1: Remove the mirror

First, the original mirror must be removed from the telescopic reflector. Use a screwdriver, Allen keys and pen to open the mirror tube before cleaning. To separate the mirror, the surrounding screws have to be turned to the previous position and you have to take out the room of the primary mirror, then separate the primary mirror.

Removing the mirror while cleaning

The mirror contains a few mirror-clips. These clips need to be removed so that the mirror can be released. But, before removing the clips, you have to mark the cell and the vertical edge of the mirror to reassemble.

Then you need to set the binoculars horizontally and remove the secondary mirror. Be careful to remove the mirror. You just need to hold the mirror with your one hand and turn the middle screw with your other hand. Then slowly bring the mirror.

Remember, two separate mirrors need to be cleaned separately.

Step 2: Wash the mirror

Wash the mirror

Now take a square rack next to the sink in the kitchen and spread a dry towel on it. Because you have to keep the mirror in it. Now wash the sink well. Then, take a plastic bowl. Keep the plastic bowl in the sink.

dry towel on a plastic bowl

Take enough pure water in the bowl so that the mirror can be immersed. Mix a small amount of detergent in that water and soak the mirror in it for 5 minutes to loosen the dust. Then remove the mirror from the bowl and wash it with tepid water and place the mirror on the towel again horizontally.

Wash it with that towel. Now another dry towel should be spread on a rectangular-rack next to the sink and the cleaned mirror should be placed upright on it to dry for a while.

Step 3: Stroking the cotton

Stroking the cotton

At this stage, fill the bowl with pure water and mix with washing-up liquid. Dip the mirror in the water once and hold it over the bowl with your left hand. With your right hand, soak the cotton pieces in the solution. Then, gently wipe with a piece of wet cotton from one end of the mirror without giving any pressure.

A piece of cotton should be used only once. Continue stroking the cotton one by one until the whole surface of the mirror is clean and discard each cotton after each stroke, but never scrub.

Step 4 : Wash with distilled water

Now empty the bowl and wash the mirror again with tepid water in it. Make sure that after washing the mirror there is no small part of the washing up liquid left. When you are sure that the mirror is detergent-free, wash it with distilled water for the last time with a slash. Distilled water is not available everywhere. It's best to find it in hardware stores.

Step 5 : After cleaning?

After cleaning telescope mirror

When the washing is done, place the mirror in a steep corner on the dry towel in the rack to dry. If you see any drops are still there, wipe with the corner of the paper towel. Wait until it is completely dry.
Set the mirror properly after cleaning, it's required for proper alignment. Your mirror is clean and ready to use. Now set the mirror with the telescope again and use it.

Remember,Clean a telescope mirror only when it needs to be cleaned. Don't clean frequently and unnecessarily, as excessive cleaning causes damages to the special coverings on the mirror.


Above all, you need to clean your telescope mirror very carefully.Remember that a little carelessness can cause a lot of damage to the mirror. Never put your sticky finger on the mirror and try not to touch the surface of the mirror. Remember, what you just see through a telescope is not very important, rather what you clearly detect and observe through it is important. So, try your best to protect the mirror from getting dirty.

If you think we can include easier steps or add some more information here, feel free to say in the comment box.

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