Cloudy OLD optics

[LewisM]

Just obtained a VERY rare old German sniper scope (I collect German firearms), and the optics are internally cloudy. I am willing to disassemble it (done it before with even scarcer stuff), but never dealt with cloudy optics previously.

Is cloudiness (lie looking though a thin fog) caused by condensation inside the scope? Or? Should the Bintel UHTC cleaning fluid take care of it?

Thanks.

[Wavytone]

Possible causes are fungus, which grows in moist air, or that at least 1 element uses an unstable or radioactive type of glass - some do change colour or go cloudy over long periods of time.

If it comes clean, consider cleaning the inside of the metalwork too as whatever it was will be coating that. Then make sure its thoroughly dry before re-assembling (several hot days) and even then you may need to use desiccant to draw the moisture out of the air inside it.

[LewisM]

I should say, the scope has become "cloudy" with age. Not sure if it's a condensation issue.

[LewisM]

Thanks Wavytone.

Spoke to an optics restorer, and he would charge $150 to clean it. Maybe...

[bojan]

Vinegar does magic to those clouds.. or saliva.
I managed to clean my Canon 300mm FD lens with it - the 4-th element was affected and the lens was almost un-useable for AF prior to cleaning.
Now it is like new.

[dannat (Daniel)]

There is a glass polish, in US I think is called ceramide, used for buffing off bad glass coatings, should be ok

[LewisM]

Thanks Bojan - will try!

[LewisM]

Originally Posted by dannat

There is a glass polish, in US I think is called ceramide, used for buffing off bad glass coatings, should be ok

Cerium Oxide - yes, I wll get some tomorrow. Thanks for the reminder about it!

[Wavytone]

If you're going to use cerium oxide it could rapidly alter the surface figure of a soft glass lens. Buy some pitch and learn how to make a polishing lap, then a least there's a chance the surfaces will stay spherical. It's not hard BTW. Main problem will be scratches.

[LewisM]

I may try acetic acid first like Bojan suggests (after trying UHTC cleaner) and then take it from there.

I need some Cerium Oxide for my car headlight lenses anyway

[LewisM]

Well, went and got some cerium oxide (FREE from my local glazier) and a big bag of iron oxide too ($2.25 from a pottery shop). Should keep me out of - or into - mischief should the UHTC and vinegar fail

Spoke to the glazier, and he said if it is water condensation, they will usually discard! Seems usually not worth the effort. Well, it is worth the effort, so we shall see

[bojan]

Just be persistent with washing, rtry to use all the mentioned stuff, plus windex (also very good), mild dish washing detergents.. rubbing with fingers and nails - polishing with cerium oxide is the absolute last resort, as it could change the shape of the lens as mentioned by Wavytone (and it removes the coating as well)

[bojan]

One more thing worth to try is ultrasonic bath (currently available for couple of bucks in Aldi stores) and mild detergent or some of agents mentioned earlier - I haven't try this method myself yet, but I will do it at first opportunity.

[cfranks (Charles)]

Glaziers and Pottery shops don't sell optical grade polishes so please don't use what you bought! You will, most likely get some very bad scratches. Comment based on my experiences long ago.

Charles

[brian nordstrom (As avatar)]

Yes sir , grab some ' Rouge ' ( face powder ) from a beauty parlor .
Brian.

Originally Posted by cfranks

Glaziers and Pottery shops don't sell optical grade polishes so please don't use what you bought! You will, most likely get some very bad scratches. Comment based on my experiences long ago.

Charles