Tried a freeze spray method on sticky aperture blades vs heat... heat wins every time for me

Been fixing old Pentax lenses for about 2 years now and kept going back and forth between using freeze spray or a gentle heat gun to loosen sticky oil on aperture blades. The freeze spray seems to work fast but the blades always gummed up again within a few months. Last week I had a Super Takumar 50mm 1.4 with blades that were basically glued shut, hit it with the heat gun at about 150F for 2 minutes and it freed up perfectly. Now I'm wondering if I just had a cheap brand of freeze spray or if heat is the better approach long term. Anyone else settle on one method over the other?

3 comments

3 Comments

sean_barnes2412d ago

Gotta disagree with you there man. I've been messing with old Minolta glass for years and freeze spray has been way more reliable for me in the long run. Heat always seems to work at first but I feel like it just melts the old grease deeper into the mechanism rather than actually removing it. My experience is that freeze spray makes the oil brittle enough to crack and flake off, then you can blow it out with compressed air. But yeah if you're just hitting it with freeze spray without cleaning the old residue out after, it's gonna gum up again every time. You gotta do the full process or neither method really sticks.

walker.julia12d ago

Nah man heat works fine if you know what you're doing, you're overcomplicating it.

colescott12d ago

Freeze spray works but you gotta hit it with compressed air right after to get all the cracked bits out. Skip that step and you're just moving the problem around.