Quote:
Originally Posted by Me2
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 |
HI Mark.
I think you will find that both his standard and enhanced overcoats use Silicon Dioxide, which is Silica rather than Quartz.
(Edit: My mistake here, the coating is quartz not silica.)
(Edit: Removed misinformation.)
I had my mirror done by him about 8 months ago and so far so good.
gb.