Hi,
This is my first post, my name is Mark and I live in Bellingen NSW. I am in the process of having my 12.5" Parks mirror recoated so thought this thread, although old, may still be relevant.
The mirror was last recoated some ten years ago but started corroding quite rapidly so I assume it didn't have a protective overcoat. I have recently got the astronomy bug again so I'm overhauling my self designed/built truss tube dob and will finish the 12' dome on my house.
For recoating I have been in contact with Matthew Lovell at Telescopes and Astronomy and since reading this thread have talked to Wayne Sainty. Wayne is just down the road (well, 3 hours drive) so will probably get my mirror coated by him.
My question is whether to go with the Aluminium + Quartz R>91% or the Aluminium Enhanced R>95% coatings.
As I live in a particularly damp environment I'm leaning towards the quartz as it may last longer, and I suspect the extra reflectivity may not be all that noticeable anyway. Looking at this article reinforces my thoughts:
http://www.oldham-optical.co.uk/Coatings.htm
Any opinions?
Cheers,
Mark
PS For those interested Wayne charges $375 for quartz and $410 for enhanced so price isn't a factor. He no longer offers Silver explaining that it tends to only be reliable on newly made mirrors. Matthew Lovell at Telescopes and Astronomy charges $440 for 95% Reflectivity including Overcoat which I presume must be enhanced aluminium. Coating removal is $15. He would also test my mirror for $35 with a printout showing the result using software.