Stuck helicoid threads fixed with a $4 heat gun trick

Had a 1970s lens come in last Tuesday with the focus ring frozen solid. Tried every penetrating oil I had, even let it soak overnight, nothing. Then an old timer told me to hit the barrel with a cheap heat gun for 90 seconds, not a torch, and twist while it's warm. It broke loose so easy I actually laughed. Now I'm wondering why I wasted a decade fighting these things cold. Has anyone else tried the heat method on those stubborn M42 mounts, or do you all have a better secret?

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the_ben12d ago

Just remember heat guns can mess with the lubricants and seals inside old lenses if you go too long. I used that trick on a Pentax once and ended up with oily haze on the glass inside. 90 seconds is fine but keep it moving and don't get cocky with the timing.