Mirror Recoating Questions

I'm a refractor person who is thinking of getting a Dob.

I have questions about buying a used Dob because of mirror coating issues.

How long do coatings last?

How much does recoating cost, and how do you find someone to do it?

Is a recoated mirror, done right, as good as a new mirror?

If you use your scope near the ocean, does that create bad coating chemistry? (if you have experience with this one, it might help to give specific distances from the water, my home is about 800 feet from the ocean)

Steve

1. Years and years with proper protection.

2. Approx 10.00 per inch of aperature, +/-, plus postage, etc. Some are less, others are more.

3. Absolutely. We just had the 26" mirror recoated for the local college observatory after 25+ years. It looked decent before and fantastic afterwards. This was my first experience with a recoat that you could actually see the difference at the eyepiece before and after. Most of the time the extra 10 to 15 % you gain isn't readily noticible at the eyepiece.

Walt