Repairing Contax cassettes

[loquax ludens]

I mentioned in another thread (What cameras can use Pre-War Contax cassettes?) that I have a few Contax pre-war cassettes. They appear to be in working condition, but upon close inspection, I noticed that several of them are missing the bottom piece of felt that should be glued inside the outermost cylinder.

At least, it appears to be felt. It's a thin black ring of material. On the inside top of the outer cylinder is a different colored ring of material that might also be felt, but it looks a bit thicker and is a slightly lighter color. None of those are missing.

Is the purpose of the rings to prevent light reflections? Felt has fibers that can come off or disintegrate into mcirofine dust that can become embedded in the emulsion. Can anyone think of a better material to use as a replacement?

 

[Bill Jones]

Contax casette felt seals

Contax casette felt seals

Hi Loquax,

Yes they are felt light seals. Black felt has been used to seal plate holders and film holders from the earliest days of dry plate photography to today.

Dust issues from the felt are not a concern since the probability of getting dust is so low from a single load of film. Also the dust would need to get by the film flange of the spool to get to the film. Dusting the inside of the casette between loads is important. Use a blower brush.

Both ends of the casettes originally had black felt. I would replace the discolored felts as they may be more apt to cause dust due to whatever aging discolored them.

Bill

 

[loquax ludens]

Thank you Bill. I very much appreciate your knowledge and guidance. I'll be visiting the fabric store to find a good replacement felt.

It looks like a 22mm and a 13mm punch will do the trick.