I have some fogging in my 135mm Optar lens on my 4x5 Crown Graphic.

See picture:

https://flic.kr/p/2kUFDgT

The fogging seems to be in between the lens elements. Is there a way to disassemble the lens for cleaning (and then reassemble it)?

The Optar is a Tessar lens, air spaced elements in front and a cemented pair in the rear. Unscrew the trim ring on the front to remove the front element. The trim ring likely has a threadlocker on the threads that will dissolve with Acetone or acetone based nail polish remover.

Awesome, thank you. I will give that a try.

Got it apart!

Used acetone on the thread, then a tool constructed from the ring that screws the shutter assembly into the back of the lens board (which is the right diameter), plus two looped pieces of blue tape wrapped to have sticky sides in both directions.

https://flic.kr/p/2m2ErgV

When putting it back together, is it recommended to put a thread locker on there again? Something like Loctite blue?

Use clear nail polish sparingly at 1 or 2 points.

This has been the most helpful info I have found for this dilemma. I hope to have the same result.

Thank you.

great work mat. where can I get one?