Telescopes are a delicate piece of technology, and they deserve great care. You will view distant galaxies with this piece of hardware, and so it needs to be in perfect working condition at all times.

Dirt accumulation on telescope lenses is a natural thing, and every telescope goes through this problem. That is why you need to know how to clean your telescope mirror effectively so that the performance of your telescope is never hindered.

There are multiple types of telescopes on the market, and each telescope requires different tactics to clean the optics telescope thoroughly. Please read below to find out how you can clean them without harming your telescope.

Taking Care Of The Optics: How To Clean The Lenses And Mirrors

Step 1: Use A Brush

Blow on the mirror if you see the dust settling in it. Use a small brush with gentle bristles to swipe on the face of the lenses, but don’t exert too much pressure. You can use a camel’s hair brush for this job.

That’s because they have soft bristles, which are ideal for this kind of cleaning operation.

Step 2: Utilize A Canister With Compressed Gas Or Liquid Propellant

The gentle brushes should take care of light dust accumulation. If this doesn’t clean your lenses thoroughly, you can buy special canisters that have compressed air that can blow the dust particles away from the mirrors.

If the canister uses liquid propellants, then you need to be more careful. That’s because they can leave spit marks on the surface, which can make your lenses hazy.

Blowing on the mirror can also cause this problem.

Step 3: Use Methanol Or Other Alcohol Solutions

Sometimes, the dust particles become stuck in the mirror. For such a situation, a quick fix won’t solve the problem, and you would need to employ other lens-cleaning solutions to do this job.

Using isopropyl alcohol can clear these tough stains. Using methanol can also get rid of dust stuck in this manner, and you can buy these solutions from a pharmacy or even a hardware store.

Step 4: Lens Pen And Cleaning Pad For Removing Fine Particles

Avoid other alcoholic solutions because these can leave permanent stain marks on the surface of the mirror.

You can also find special fluids sold in camera stores that can clean your lenses. A “lens pen” can also clear dirt with its soft and solvent-induced cleaning pad.

The Do’s And Don’ts Of A Telescope Mirror

  1. There are many tactics you can employ to guard against dust from settling in your telescope lenses. A defensive ploy would be to always keep the lens cap on when your telescope is not being used. If there are no caps available, then you should make a cap by yourself. This small action can greatly reduce the amount of dust that settles on the lenses.
  2. Store the telescope mirrors on the downside so that it is facing the ground. Gravity will help wade off most of the dust particles as the mirror is not facing upwards. Get hold of durable caps that can seal your eyepieces from both ends.
  3. Never, under any circumstances, touch your telescope mirror or the lenses. Your fingertips are filled with fatty acids that erode the coating of the optical mirrors gradually. If you accidentally touch it, then you need to immediately use a disinfected cloth to clean the smudge marks on the mirror.
  4. Dust is a natural thing, and you shouldn’t worry too much about it if it’s minimal. It can always be cleaned with a fine piece of cloth. However, excessive cleaning can cause scratch marks to appear on your telescope mirror, and that is something that can severely hamper the performance of your optics. Thus, clean your telescope with great caution, and do it only when it’s necessary by following all the steps outlined in this article.

Stay Away From Applying Any Solutions Directly On The Mirror Surface

Do not apply any cleaning solution directly onto the lens itself. Use a soft cloth or cleaning pad and dip that into the solution before cleaning your mirrors.

This is because the liquid solvent can seep into the mirror and affect the performance of your telescope.

The wipes need to be gentle. A clean piece of cotton can be used as a cleaning pad. After a light dap on the cleaning solution, moisten the cloth and apply a small amount of pressure with the wipe. You can also use a dry rub to clean the mirror without any solvent first.

Practice Caution While Cleaning And Taking Apart The Mirror

Remember: Do not drop any liquid solvent directly on the surface of the mirror.

This may permanently damage your telescope because the solvent reaches areas that are difficult to reach with a human hand. An eyelash or fingerprint mark can also cause permanent discoloration of your lenses.

So, don’t leave them on long enough and clean them immediately if you suspect your lenses have fingerprints on them.

If you suspect your eyepiece mounts to have problems, you should not take it apart yourself. These are very delicate pieces of hardware, and you may cause it to tilt if you take them apart.

Instead of taking the matter into your hands, call up your telescope manufacturer or request a professional to fix the problem.

Different Cleaning Procedures For Different Kinds Of Telescopes

Refractor telescopes and telescopes that use mirror lenses have eyepieces solidly shut, and you should not take apart the cells by your own accord. You carry the risk of damaging the glass and chipping at the interiors.

You will also find it difficult to re-assemble the eyepiece once you fix the problem. Don’t think of taking any shortcuts if you have big lenses. It will just need more diligence and time from your part and resist all the urges to employ quick fixes.

On the other hand, if you have a reflector telescope, you can easily take apart the eyepiece and put it back together once you have finished cleaning the lenses.

But, you have to be very confident about putting it back together to exactly its previous form and collimate the telescope once you do so.

How Can You Tell If Your Telescope Mirror Needs Cleaning?

If you are careful with your telescope storage, chances are that it rarely needs to be cleaned. Although extensively using your telescope outdoors may mean that it gets dirty.

To take apart a reflector telescope, you need to locate the screws that are holding the mirror on the back. Slowly pull out the cell and gently unscrew the clips, and then push it from the backside. Do not touch the shiny mirror surface while unscrewing.

After that, you need to remove the holder for the secondary mirror and then casually pull it out. Practice great caution while doing this maneuver. Once both the mirrors are pulled apart, you need to carefully remove the grit thoroughly.

Household dust contains rock powder, and rubbing it may cause sleeks to appear in the mirror. Thus, you have to remove grit without rubbing on any glass surfaces.

Leaving skid marks and other scratches on the surface of the mirror can lead to permanent damage, one that cannot be fixed. Thus, vigilance can help you stay clear of such problems while cleaning the telescope mirror.

Things You Need For Cleaning

First of all, you need your kitchen sink for this operation. This is where you will perform all the cleaning. You also need two pieces of cloth; you can use towels for this.

A bottle of water that is distilled and free from any ionization is something you can buy from your local drugstore. A pack of sterile cotton which is free from any grit, and you are all set!

Step 1: Rinse The Kitchen Sink Thoroughly

Rinse the kitchen sink thoroughly and make sure it is properly cleaned. Fold a towel and place it on the sink. Ensure that your hands are free from any jewelry.

Now position your mirror above the folded towel, and turn on the sink for a few minutes. The blasting of water will take care of most dust and grit from the surface of the mirror.

Step 2: Blast Off The Drain And Use Cotton

Turn off the sink and use the sterile cotton to clean the remaining residue on the mirror. Gently wipe the surface without exerting too much pressure.

Before wiping, use lukewarm water to wet the piece of cotton.

Finally, use the sink water and then use the distilled water to clean the mirror again.

Step 3: Let It Dry

Take another towel, fold it up, and then set the mirror in a tilted manner to let it dry. The distilled water will remove any remaining residue on the surface and get rid of all the dust particles that were stuck there.

After a few hours, your mirror should dry off. If a few water droplets remain on the surface, use the towel to gently wipe the edges of the mirror.

Getting Rid Of The Persistent Dust

If there are particles still stuck to the mirror surface after this procedure, you have to perform another cleaning procedure because you have to get rid of other particles besides household dust, which is easier to clean.

Step 1: Fill The Sink Halfway With Lukewarm Water

Take off the towels and plug the kitchen in sick. Set the drain on full blast and fill half of the sink with lukewarm water. Then apply a dash of liquid detergent to the sink and place the mirror inside this kitchen sink for 10 to 15 minutes.

Then you have to swirl the mirror around and shake it gently to remove any remaining grit from the surface.

Step 2: Gentle Wipes With Sterile Cotton Swab Under Submerged Water

Take a piece of cotton and wipe the surface without exerting more force than the weight of the cotton itself. Grit is easier to get rid of when submerged in water, so do not take out the mirror from the sink while doing this action.

If you have a big mirror, you may need plenty of cotton for the cleaning job. It is highly advisable that you clean in a nice and quiet environment.

This is because you can hear the sound of sleeks if you are incorrectly cleaning the lenses and stop immediately once you notice the sound.

Use the same steps to clean the secondary mirror. In the final step, turn on the drain and rinse the mirror for a minute or two. Apply distilled water at the end. After this, place the mirror on its side edge and keep it there for a few hours to dry completely.


Telescope mirrors can be cleaned by following some basic steps which can extend their lifespan of them.

But if you happen to run upon an antique telescope that is rusted up pretty badly, you should take the help of a professional to clean that equipment as you simply cannot do it alone. It may be expensive, but it will still be cheaper than buying a brand new telescope.

Your attitude plays an important role in maintaining your telescope lenses. If you are mindful about the storage of your telescope and keep the optics well sealed when not in use, you can prevent dirty scopes and mirrors.

Perfectionists are never happy with a dirty telescope, and so should you. Telescopes are a fun hobby, and cleaning them is another part of this package.