Hello all,
I just bought a Fujica ST801 on the internet and found suspicious stains on its shutter curtain. Please see the images below. Could someone please offer some insight as to what they are and how I should clean them? The shutter curtain works fine. All the shutter speeds are accurate. Part of the shutter curtain is clean - the part that faces the film when the film advance lever is not cocked (1st curtain). However, once you cock the film advance lever, this dirty messy part of the curtain emerges, the 2nd curtain.
There is considerable rust on the camera's interior, so it probably has been stored in a humid environment in the past. Yet I don't smell any musty smell. Could it be mold? It almost looks like some kind of water damage. If it's mold, I'd hesitate to use it because I assume it might contaminate my M42 lenses. What would you suggest as a way to clean it?
I am inclined to clean it with q-tips saturated with 91% alcohol. Is that advisable? Would you rather suggest 9% vinegar? I just want to make sure I don't mess up the speeds of the shutter, which is still accurate now, or don't apply something corrosive enough to leave a hole on the curtain. Any experiences you have had with such mechanical shutters would be much appreciated! Thank you guys! - Han