I have disassembled a lens for the first time. The Konica Hexanon 50mm f/1.7 I bought at KEH had a sticky aperture that would not close to the correct setting before the shutter would release. Luckily I discovered this before ruining any film and KEH replaced if for free and allowed me to keep the lens with the sticky aperture as well. Since it was a freebie I decided that I had nothing to lose in performing surgery to determine the cause of the sticky aperture and attempt a repair. The partial disassembly required to expose the parts causing the problem was easier than expected. What I found was that a previous owner/user of this lens most likely attempted to lubricate the aperture mechanism. This did nothing but gum up the whole works over time by collecting grime and causing it to move very slowly . I used alcohol to clean it up and the aperture works fine now. The one problem I had was that some of the alcohol (I probably used more than I should have) made its way into the lens barrel and looks as if it has condensed on and spotted the inside of the lens elements. This may be temporary but its been there for about 12 hours now. Has anyone had experience with this before? Suggestions? If it doesnt go away Im considering taking out all the glass and cleaning it.