filter cleaning

[AstralTraveller (David)]

I've just been asked to help someone clean their ND filter with alcohol to remove fingerprints. I have good clean ethanol, not just metho. Before I agree I want to check whether this is the best way to clean and whether it will do any damage. I'm a bit concerned. BTW I also have clean methanol, acetone, hexane, DCM and probably a few others if any of these are better.

[inline_online (Dan)]

Wow, I wonder what would happen if you mixed all those chemicals together...[BOOM]

I use a little bottle of lens cleaner from a camera shop for all my scope cleaning requirements. No idea what the active ingredient is though.

[astro_nutt]

Check to see what cleaning requirements are for the filter first. Ask your local Pharmacy for some Isopropyl alcohol. Blow off the dust first then dampen the corner of a plain Kleenex and draw the dampened corner across the filter with the weight of the tissue only..no pressure!...one direction once only then use another corner.
Cheers!

[LewisM]

I use propanol to clean glass (isopropyl alcohol). The film grade one is superior to the ones from Bunnings etc. Photographers used to use it to clean film backs (NOT the emulsion side!!!)

DCM is not something you want to be touching without chem resistant latex gloves. Dichloro Methane has a tendency to do wonders to your fertility... SERIOUSLY. Some pass it off as a low risk, but WHY risk it? We use DCM on a regular basis in the lab, and full lab coat, latex gloves, eye protection. I have splashed it on myself once or twice - not very pleasant.

I would not put acetone near ANYTHING astronomical - it'll remove the paint on tubes, eyepiece barrels etc etc. NOT a good idea! Hexane MAY also remove some celluloid paint, though it does have a low vapour point, so may evap fast enough (acetone does too, but eats quickly too!)

Propanol is your safest bet - it removes the wax etc of fingerprints very well