PSA: Watch out for old Canon AE-1 shutter curtains, they can turn to dust
I was working on a customer's AE-1 last week, a real clean-looking unit from 1980. The complaint was a shutter that sounded slow. I got the top cover off and was checking the mechanism when I gently brushed the rear curtain with a spudger. A whole section just flaked away into black powder, like charcoal. I froze. The curtain material had completely degraded from age. I had to call the owner and explain his shutter was now a goner. Finding a donor curtain is tough, and a full CLA with curtain replacement ran him about $180, which he okayed. It was a real lesson in how these old rubberized fabrics just don't last forever. Has anyone found a good source for these, or a decent repair method that doesn't need a whole donor body?
Man, that crinkle sound jennyp19 mentioned is the worst. I had an old Minolta where the curtain just sort of dissolved when I tried to clean a tiny spot, left this weird sticky black residue all over the gear train. It smelled like a burnt tire.
My 1982 AE-1 Program did the exact same thing last spring. I was just advancing the film and heard a weird crinkle sound. Opened the back and saw a bunch of black flakes on the pressure plate. It's such a gut punch. I ended up buying a broken body for parts on eBay just for the curtain, which cost almost as much as a working camera. I've heard some people try to recoat them with liquid rubber, but that never seems to last.
Actually my buddy in Portland fixed his curtain with Plasti Dip three years ago and it's still perfect. He just did two thin coats with a tiny brush after a careful alcohol clean. The key is letting it cure for a full week before you wind the shutter. I know the horror stories, but a proper DIY job can outlast these old factory adhesives.