The first camera I ever bought was a used Praktica LTL with CZJ Pancolor 50/1.8. That developed sticky aperture blades at some point in the late 90s/early 00s when I wasn't doing much photography and it spent most of its time in a box on top of the wardrobe.
Originally Posted by Ian Grant
Earlier this year I finally plucked up courage, found some instructions online, dismantled the lens and gently cleaned the blades with IPA and cotton buds. Working perfectly now, and having gained a little confidence working on a low value lens I moved on to my P6-mount CZJ 120/2.8 Biometar that suffered from the same problem. Happy to relate that is now fixed too and once again in use.