That one trick for cleaning helicoid threads everyone seems to skip

I've seen so many repair posts online where people go straight to relubricating a stuck focus ring without actually cleaning the old grease out first. In my experience, you need to fully remove the old compound using a solvent like naphtha or even lighter fluid before putting anything new on. I had a Pentax 50mm f1.4 come through last month where the previous 'repair' just caked new grease on top of hardened old stuff. It made the focus feel gritty and rough after just a week of use. Has anyone else run into this where a simple clean would have saved a lot of hassle?

3 comments

3 Comments

rosepark7d ago

Wait people actually do that, just slapping new grease on top of the old gunk?

casey3427d ago

That Pentax 50mm you mentioned, was the helicoid already showing brassing from the grit before you got it?

bell.jessica7d ago

Wait did you check the helicoid before you bought it? I made that mistake once. Bought a vintage Takumar online, looked clean in photos but the helicoid was gritty as hell. Previous owner just slapped thick grease over the sand and grit instead of cleaning it out. It brassed through the coating in like six months. I had to completely disassemble it, flush out the old gunk with lighter fluid, and re-lube with proper damping grease. Night and day difference. So yeah, if the brassing is already there from grit, it's been used dirty for a long time. Never again buying a lens without asking for a helicoid feel video first.