Cleaning Brass / Old Lenses

[Steve_7x]

Not 100% sure if this is the right place to post, but the lenses in question are for larger format types and are old...

Anyway... I recently got a couple of uncoated lenses that are a bit dirty. One is just plain dusty dirty, and another appears that it might have a layer of some kind of film on it (I hesitate to call it haze...).

How would you propose that they be cleaned. Do I just use lens leaning material and a microfiber lens cloth? Is there a better way?

Just looking for some good ideas on how to clean up these classic lenses.

Thanks in Advance!
Steve

 

[Jim Noel]

activated charcoal on a Q-tip. Use in a rotary motion. No liquid to get around the edge and into the cement. It works wonders.

You may have to take the lens apart and clean inner surfaces also.

If there is fungus on the lens, use Listerine. Yes, the mouth wash.

 

[Kerik]

Steve - Astronomers use collodion to clean the lenses of their telescopes. I know where you could get a small quantity locally, if you want to try it...

 

[Harrigan]

What you want to do is get a clean peice of cotton or other soft fabric and lightly wet it with water and dab off the dust. The last thing you want to do is swirl dust and dirt around on the lens surface, this is what leads to cleaning scrathes. You need to get the dust and dirt off first before taking a lens cloth to the glass. For cleaning acetone is commonly used by optical assemblers to clean glass. When I use acetone I follow it with a very light water then a clean dry lens cloth. Most of all remember to get the dust and dirt off the glass before wiping lenses with anything.

 

[Steve_7x]

Thank you all... excellent feedback!

Kerik... I think I know who you are talking about. I will drop you a line when I get back in early March...

Steve

 

[Murray@uptowngallery]

I use a variation of a recommended recipe

ammonia
hydrogen peroxide

I can never find ammonia (in the house) when I need it, so my recipe is:

Windex 50% mixture
3% off-the-shelf hydrogen peroxide (about 12.5% mixture)
isopropyl alcohol (about 12.5% mixture)

I have heard that Sparkle actually has some abrasive material in it, adn it is not ammonia-base, so don't substitute.

I have two lenses that did not clean up with this were coated; one may actually have very mild fungus damage in the coating or I need something stronger (tbd), and the second lens had distinct pitting in the coating and glass. The pitting had black in it. I assume this was a case of fungal damage beyond recovery.