I'm pretty new to IIS.
Been out of the hobby for about 10 years, just getting interested again now.
I thought I'd post this for interest sake on a 10" custom mirror I had made by an esteemed mirror maker in the USA in the late nineties; I started this project in response to cancelling an order I had placed for an AstroPhysics 155 Starfire EDFS...(I had got engaged & decided to put the money into a house rather than a scope!).
After I received the mirror (which I'd payed top dollar for), I noticed a mottled effect when you looked across the mirror at a low angle. After I'd used the scope for about 6 months, I had become concerned about this enough that I ended up sending it to Francis Lord Optics for assessment in feb. 2000.
Glenn Davis at Francis Lord assessed the mirror and provided me the photo & report which I've tried to attach here for interest. Glenn was really fantastic with the assistance he provided me.
He said that he thought the mirror had become stained by something associated with the cleaning process prior to coating it (by a US based coatings company who is still in business today
- certainly not aided by my patronage!). Also, he said the coating (which was meant to be an 'enhanced' coating!) was only about 1/3 as thick as it should have been... meaning it wasn't anywhere near as reflective as it should have been).
Glenn said he thought the only way to fix the problem was to repolish it!!
You can imagine the stress this caused me!!!
A mirror I had willingly paid so much for, in comparison to buying a 10" off the shelf!
He recommended Mark Suchting to re-polish it, which Mark duly did for me. Boy, had I known Mark was making great mirrors locally, I would just have gone to him in the first place! You live & learn. (I'd be interested in Mark's recollections if he sees this??)
Anyway, Francis Lord put a quartz overcoat on it after re-coating & sent it back to me in sept. 2000 ... Needless to say, I've been very happy with it since then. I've had some great views of the planets. Certainly happy with Mark's work.
It now needs a bit of a clean - not bad for ~15 years without being touched! So I'm going to pull it out of it's cell soon to do that.
Russ
