My mentor at the Rochester repair bench swore by lighter fluid for sticky shutter blades, and he was dead right
Six years ago I brought a jammed leaf shutter from a folding camera to an old timer named Ray at his bench in Rochester, and he dabbed it with a drop of lighter fluid on a toothpick instead of tearing it down. I figured he was cutting corners, but the blades snapped clean through ten cycles and the flash sync timed right on my tester. I've used that trick on about forty shutters since, and every one that came back open again was one where I got greedy and flooded it. How much fluid do you all use on a really gummy Copal, and does anyone have a shutter that burned them on this method?
Figured lighter fluid was a hack til Ray showed me otherwise, now it's my first move on a gummed up Copal. Flooded one once and it came back stuck worse than before, so just a touch on a toothpick and work the blades.