pollution on corrector plate

[Joshua Bunn (Joshua)]

Hi Everyone,

I have some spots on my LX 200 ACF corrector plate, they only show up when there is moisture applied, such as breathing on it. When there is no moisture, the plate is spotless (literaly ). As i live in a relatively clean part of the country in terms of atmospheric polutants, my only thought that it could be is woodfire smoke settling on the plate from a dewy evening.
I now use a dew shield to help this situation.

I would like to hear from others in relation to if you have experienced such deposits on a observing night when there were fires burning (fires to warm houses), and wheather it left any permanent marks on the corrector plate, and if so how were they removed. I bought the bintel solution and tried that, it reduced the spots slightly but they are still there. i have gone over it twice.

My concern is image quality.

I have attached 2 examples of each situation - no moisture and with moisture (breath). And i see the streaks - need to clean that up .

Thanks for looking.

Josh

[Poita (Peter)]

Mine was very similar to that, just a buildup of airborne grease and crap.

I made a solution according to this page:
http://astrosurf.com/luxorion/reports-cleaning.htm
and it took about 5 goes to slowly and gently remove the film of crudola.
You can leave the corrector plate on the scope, the very very edge probably doesn't matter that much. Mine ended up perfectly clean again. I also tried the Bintel solution, but it didn't work well for me.

I ordered a bottle of Craig Chemicals 99.9% Isopropyl alcohol from my local chemist. They got it in, it took a few days. I don't trust the one from Bunnings, but it is probably fine.