Eyepiece disassembly - bad idea?

[Sauerkraut]

There isn't much info available on disassembling eyepieces for more thorough cleaning. The Nikon Optiphot CWF eyepieces look like they come apart with a spanner wrench. Is disassembly a bad idea with unseen pitfalls or reasonably manageable? The wrench would unscrew a collar that holds the top lens in place.

A tool like this might work:

https://www.ebay.com/i/253147784292?chn ... gIKvfD_BwE

[75RR]

I have opened Zeiss eyepieces to clean the lenses. No problems as such, but you do have to keep track of the lens order to be able to put them back correctly.

[PeteM]

If you have the proper tools, cleaning eyepieces makes good sense.

Three cautions. First, make sure you very carefully observe the orientation and order of lenses as you take them apart. Many of the individual lenses need to go back in the same order AND direction as original. Take notes.

Second, it's trickier to clean reticles if those are present. The slightest bit of dust or smear will show up. Some rulings are fragile or unhappy with lens cleaning solvents.

Third, as you're screwing lenses and spacers back together take care that the lenses seat properly. It's easy to crack the glass edges if things don't center and settle just right into their recesses. Don't force things.

[Sauerkraut]

Thank you, 75RR and PeteM. Really good information, especially on lens direction and orientation. The reticle was loose and fell out, probably from the exciting shipping excursion.

I managed to get one apart and it's a contained lens canister so fairly easy. The other one has what looks like superglue on the seams and probably is not going to come apart.

The one that came apart has oil on the bottom lens from what looks like assembly lube. Is there something that takes oil off without ruining the coatings?

[Sauerkraut]

I answered my own question - just kept lightly buffing out the oil with Q-tips and Purosol Optical lens cleaner and then a dry Q-tip in between runs.

Incidentally I've found Purosol followed by Sparkle for the final pass is a really nice one-two punch for optics cleaning.