A stuck shutter blade on a Nikon FM2 taught me a new trick

I was working on a customer's FM2 from a local estate sale, and the shutter was completely locked up, not firing at all. After removing the top plate, I found a tiny piece of dried foam sealant had migrated and was jamming a primary blade. I used a drop of lighter fluid on a cotton swab to gently dissolve the residue without taking the whole curtain assembly apart. Has anyone else found a safe solvent for cleaning old foam off brass gears without harming the lacquer?

3 comments

3 Comments

the_julia7d ago

Doubt it actually etches the brass that much.

viola_garcia567d ago

Yeah, the "acidic over time" part really got me thinking. Old foam can totally hold moisture against the metal for years. That slow, constant dampness might be doing more harm than a quick spill. It's not like a strong acid, but even a tiny bit of corrosion over decades adds up. You might not see it until you strip the finish and find pitting underneath.

anna7177d ago

That lighter fluid trick is clever. Wonder if the old foam turns acidic over time and starts etching the brass underneath, even if the surface looks clean.