I've had a lot of success with eyepieces, done exactly as described here:apochronaut wrote: ↑
Tue Dec 05, 2023 12:27 pm
Are you sure it is Canada Balsam?
I don't know what cement was used. It is the eyepiece from a Zeiss PM III, so mid-seventies vintage. The center is perfectly clear, but there are about a dozen semicircular incursions from the perimeter that look grainy.
The right cement is Ceadax indeed.You have to disassemble the eye-piece. There is one optical element consisting of two lenses glued together. The delamination is in the glue. Put the element into xylene for a few days. Then carefully place some Ceadax around the border line between the two lenses and put it into a xylene saturated environment for some more days. Clean the element with xylene from any residue and reassemble.