How to unscrew a stuck retaining ring?

[Alan Gales]

Sorry. That's PB Blaster!

[c.d.ewen]

+1 on the PB Blaster. I was told the local shipbuilders (big saltwater craft) keep a supply on hand for corroded nuts.

Have you considered cutting away to lensboard?

Charley

[domaz]

When all else fails you have to do something drastic. I think it's time to get the Dremel out. Cutting away the lensboard seems like a good idea. You could also directly cut the retaining ring with the Dremel but that is risky as it would be easy to go to far and cut the threads of the shutter.

[alps-art.ch]

Have you considered cutting away to lensboard?
Charley

As the last mean, yes. But rather break the retaining ring. How one can cut away lensboard?

[alps-art.ch]

When all else fails you have to do something drastic. I think it's time to get the Dremel out. Cutting away the lensboard seems like a good idea. You could also directly cut the retaining ring with the Dremel but that is risky as it would be easy to go to far and cut the threads of the shutter.

I poked Dremel website, there are at least 4 tools - Rotary, Multi-Max, Trio, Saw-Max. Which one of Dremel tools did you mean?

[c.d.ewen]

Dimitri:

What's the lensboard made of? Wood? Metal?

Charley

[alps-art.ch]

What's the lensboard made of? Wood? Metal?

Metal, a kind of aluminium alloy

[bobwysiwyg]

You would need a second set of hands, and possibly end up sacrificing a wood chisel, but you can hold the chisel at an oblique angle to the ring to get a bight, and give it a shot with a light hammer, obviously in the direction of unscrewing. Best done hitting downward with the board edge on a bench with someone holding the board perpendicular to the bench. If it works, there might be a slight nick in the ring, but...

[cyrus]

Wow this retaining ring is turning into quite a saga, huh!

[alps-art.ch]

You would need a second set of hands, and possibly end up sacrificing a wood chisel, but you can hold the chisel at an oblique angle to the ring to get a bight, and give it a shot with a light hammer, obviously in the direction of unscrewing. Best done hitting downward with the board edge on a bench with someone holding the board perpendicular to the bench. If it works, there might be a slight nick in the ring, but...

Yes, I see what you mean... but I am still hoping to accomplish without drastic exercises