PSA: I thought soaking old aperture blades in naphtha was a hack, then a Konica Auto S2 changed my mind

Emery Craig · 2026-10-01T17:25:04.627234+00:00

I always figured the naphtha soak was one of those internet shortcuts that just smears oil around instead of fixing anything, and for the longest time I told people to stop doing it. Then a customer brought in a Konica Auto S2 from a garage sale in Sacramento, sticky blades, mirror locked up about every third wind, and he said he was fine with me using it as a learning project since the camera only cost him $12. I pulled the front element, dribbled naphtha into the aperture housing with a syringe, worked the ring maybe 60 or 70 times, and let it sit overnight. Next morning the blades snapped shut like new and stayed dry, no oil creeping back onto them after a few hundred test fires. What convinced me was pulling the lens back apart after two weeks of daily use and seeing the blades still clean and dry, not a film of gunk anywhere. The catch is you have to flush it properly and get all the old lube out, because a lazy soak with no follow up cleaning will just come back in a month. Anyone here had a soak job go bad on them later, or is it holding up fine after a few months?

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PSA: I thought soaking old aperture blades in naphtha was a hack, then a Konica Auto S2 changed my mind | Camera Repairers - Opinions Matter