Mirror cleaning

My Meade DS1200 has been sitting unused in my garage for several years, and I discovered the reflector has become quite hazy. I know little about the finish on these mirrors, but I feel I should get some expert advice before squirting Windex on it and wiping it with newspaper. How should I go about cleaning it?

Ed

Hi Ed,

Here is how I successfully clean my newtonian mirrors:

You need the following supplies:

1. Surgical cotton - purchase this at a drug store NOT COSMETIC PUFFS OR COTTON BALLS - they contain impurities that will cause you problems. This cotton usually comes in a box rolled up in paper.

2. A gallon or two of DISTILLED water. NOT SPRING WATER or anything else - these contain minerals which will leave deposits on the mirror.

3. A drop of Ivory dish soap (unscented).

Once you obtain these supplies, do the following:

1. Remove the mirror from the scope and from its cell.

2. Set mirror flat on a large dishcloth in the sink to keep it from scratching your sink and/or damaging the back of the mirror. (You might want to remove rings or any other jewelery that may get in the way or scratch the mirror).

3. Run WARM (not hot) tap water over the surface of the mirror for several minutes to wash away the larger pieces of dirt and impurities.

4. Put one drop (no more!) of Ivory dish soap in about 2 cups of warm water and stir it up so you have a good even solution.

5. Pour the soapy solution on the surface of the mirror until it begins to overflow the edge and let it sit for a few minutes.

6. Take surgical cotton and pull off decent sized pieces. Soak the cotton in the remaining dish soap solution and then gently drag it over the surface of the mirror. DO NOT SCRUB OR APPLY ANY PRESSURE! Don't re-use the cotton once you have made a pass or two across the mirror - replace it with a fresh piece.

7. Rinse mirror thoroughly with warm tap water. DO NOT LET THE SOLUTION OR TAP WATER DRY ON THE SURFACE!

8. Carefully lean the mirror vertically against the sink or in a dish drainer, making sure that it does not slip and fall flat.

9. Liberally pour distilled water over the surface of the mirror. I usually use 2 gallons on my 20" mirror and 1 gallon on my 10" mirror, but that's just me.

10. Allow mirror to AIR dry completely. If you have small droplets of water at the bottom that remain after the rest of the mirror is dry, take a tissue and just touch the droplets to soak them up.

11. Reinstall the mirror in the cell and then mount back into the telescope.

You are ready to collimate!

This alls sounds more ominous than it really is, but it isn't that bad!

Other folks may have a different approach or want to throw in their 2 cents worth on my approach, which would be great!

These mirrors have **very** thin front surface coatings that can scratch easily. Some of the newer overcoated mirrors offer better protection. Hope this helps (if you haven't fallen asleep reading this by now!!) Steve