I finally found why my shutter speeds were off on that old Pentax

Had a customer bring in a Spotmatic last month with inconsistent exposure. I checked everything - springs, gears, even cleaned the blades twice. Turns out the problem was dried lubricant from the 1970s that had turned into glue. Took me three tries with a specific solvent blend to get it moving smooth again. Anyone else run into old lubricant causing issues in 40+ year old cameras?

3 comments

3 Comments

murray.cora1mo ago

Tbh that "dried lubricant from the 1970s" line hits hard. I had a Pentax ES II earlier this year that was stuck solid, and it was the same problem. The old lube turns into this hard, sticky residue that jams everything up, especially if the camera sat in a warm closet for decades. I used a mix of naphtha and isopropyl alcohol, let it soak in for about an hour, then worked the gears slowly with a toothpick. You really gotta be patient with that stuff, rushing it just bends the tiny springs.

leo_black761mo ago

Yeah, the warm closet thing is real. I had a Minolta SRT that sat in an attic for years and the lube basically turned into tar. @murray.cora is right that rushing it bends the springs - I broke a tiny shutter blade spring on a Fujica once by forcing it. The naphtha/isopropyl mix works, but I also had luck with lighter fluid on a really stubborn Copal shutter. Just gotta let it sit and work slow, no shortcuts with this vintage gear.

viola_lopez301mo ago

Your comment about the warm closet really hit home. I had a similar experience with an old Minolta SRT that my uncle gave me. It had been stored in a garage for over a decade, and the shutter was completely locked up. I tried the lighter fluid trick on the Copal shutter too, and it worked after a few hours of letting it soak in. The patience part is so true - I remember getting frustrated and nearly forcing the advance lever, but catching myself just in time. These old cameras really test your resolve, but the payoff when they start working again is worth it.