Lubricating a lens

[Vultch]

I have two old zoom lens in great condition.

They are of the design you twist or rotate the barrel to focus and push/pull the barrel to zoom.
One lens is perfect but the other is a little stiff, I am very reluctant to add a drop od light machine oil onto the barrel in case it makes its way into the optics

Any suggestions

 

[Run&Gun]

I presume you're talking about still lenses. Ken Rockwell had a list of camera repair guys/shops that are good with old gear on his site. Saw it earlier this year. Might be worth checking out.

 

[Publimix]

I would not use thin oil. Maybe thick grease. (silicone) Google for 'grease and lens' and you will find some interesting sites.

 

[Greg_E]

Microtools has the grease you will need, but it's far harder than adding a drop to an external point.