If you have a reflector telescope, you are likely aware that you need to clean the mirrors. In this article, we explore how to clean a telescope mirror.
With use your telescope will attract particles of dust and dirt. This material will inevitably become stuck to your mirrors. While a little material will have little or no effect on image quality, a large amount may.
Generally speaking, cleaning your reflector telescope every 5 to 10 years is recommended. However, some people do this a lot more often.
When considering cleaning your telescope, remember that it is a delicate instrument. By taking it apart, you run the risk of damaging it. If you do not feel up to the job, consider consulting a professional. If you are a member of an astronomy club, someone may be prepared to help you.
We recommend cleaning your reflector telescope every five years. By this time the mirrors will likely have accumulated enough dust and dirt to make cleaning beneficial. However, it has not built up to be too much and make the job too difficult.
You can clean the mirrors yourself, which is what this guide is going over. However, it is worth remembering that many people will get the reflector telescope’s mirrors professionally cleaned. This is because they are incredibly expensive to replace, and you do not want to risk damaging them.
But if you do not have the budget to get this done professionally and you trust your ability to do it yourself, keep reading to get a simple guide on how to do this!
What You Need to Clean a Telescope Mirror
As well as your telescope you will also want to have some high-quality dish soap. This will be used on your mirrors.
You will want some cotton balls as well as a high-quality towel. It must be lint-free so it does not leave anything on the mirrors. You can also try a microfiber cloth alongside the towel.
You want a set of standard screwdrivers to aid with taking the reflector telescope apart. The last thing you will need is some distilled water as well!
Step-By-Step Guide
Make sure you have everything you need close by before you start working.
While your reflector telescope is being disassembled, you want to be as careful and organized as possible. You do not want to be disorganized and uncoordinated. It is best to keep things organized. If available use a board on which you can write next to items to aid when putting the telescope back together.
Before commencing, we recommend first reading the following instructions from start to finish. Furthermore, we recommend that you take photographs throughout this process so you know exactly how the reflector telescope will go back together. If you can take a video as you disassemble the telescope.
Also, remember that following this procedure you will need to collminate (or align) your telescope’s mirrors.
Remove The Primary Mirror
Firstly, you will want to remove the primary mirror.
Reflector telescopes are built slightly differently. However, they have similar features, so disassembly will be similar.
First of all, locate the screws for your primary mirror. This will be located at the back of the tube.
If you’re unsure, look up a guide to taking apart the specific model of reflector telescope you are working with.
Once the mirror is removed, you can remove the holding cell. Ensure not to damage the mirror with your screwdriver.
Remove The Secondary Mirror
Taking out the secondary mirror may require being more careful than you were with the primary mirror since it will usually be in a more awkward position.
This will involve locating the securing screws and removing them.
We recommend following the advice from the previous step by looking up details for your specific model and taking pictures for reference as you go!
Clean The Mirrors
Now, this is the main part of the process. Ensure you have all the mirrors removed from their holding cells.
You will want enough warm water to submerge the mirror fully. The mirrors are washed using normal tap water, not distilled water.
Next, add just a small drop of your soap. This will make the water only slightly soapy which is how you want it, so not big clumps of bubbles.
Carefully handle your primary mirror and avoid getting fingerprints on it. Place it in the water, moving it around carefully. Gently remove any loose particles and repeat the process with your secondary mirror.
Then once they are clean, you can place them vertically on a drying rack. Then you can drain your water!
Now make a fresh batch of water and again clean the mirror. This time remove any excess dirt using cotton balls from the center outwards using minimal force.
Do this until you have a clean telescope mirror. Ensure you are only using the clean edge of the ball so you are not smearing any dirt back on.
Do this with both mirrors. Then drain your cleaning water. To remove watermarks pour distilled water over your mirrors. A spotless mirror will provide the best images.
Once you have used the distilled water, you want to use your clean towel to soak up any excess water.
You find that some people use hairdryers. However, the excess heat can induce stress in the mirror. We recommend carefully using a towel followed by air drying.
You may need to repeat the process if you are unhappy with the results. Repeat the process until you are happy with the dry final product.
Put It Back Together
Once your mirrors are clean and dry, you will want to put your mirrors back into your reflector telescope.
This can be a lot more stress-inducing than you would imagine, especially since you are putting screws near your freshly cleaned fragile mirrors.
You want to ensure that you are being as careful as possible.
Ensure you refer to the reference photos and/or those you took when disassembling. If you are not confident seek professional help or find a guide for your specific model.
Once the telescope is re-assembled, you must colliminate it to align the telescope’s optics.
This is how you clean your telescope mirror on your reflector telescope. We hope this guide has given you all the information you need. The process is not too difficult but requires time, precision and care!
Hi, my name is Jason Anderson, and I am a Physics Professor. Ever since I was a kid, I’ve been fascinated with space, the universe, the moon, you name it. I spent hours and hours at the planetarium close to my hometown, wondering what else could be out in the universe.
Since then, I’ve been an avid stargazer and astronomer, and love nothing more than spending my time charting stars, observing planets, and finding constellations.
This is why I decided to start Telescope Guru. I only wish to share this fun pastime with the world. With this site, I hope to answer all of your questions relating to astronomy, telescopes, and stargazing.
