retaining ring too tight

[MartyNL]

As a last resort a dremel may be able to save the thread of the shutter if I cut through the lens board. I’d really hate to lose this Prontor Professional.

Wise decision. Although gnawing through the retaining ring might be on its own, sufficient.

[MartyNL]

I will admit, that I found my one 'welded' retaining ring episode so 'traumatic', I've taken to asking about being able to remove lenses from lensboards, before all future purchases!

[kunlun121]

OK, so mine has not been glued. I am going to try with some WD-40.

[rfesk]

The spanner I used was very similar to the one suggested by jim_jim. Once the blades are fit into the grooves of the filter ring, hold them tight to the ring with your fingers down close to the ring and then twist.

It worked for me but I was very careful not to damage anything if the blades of the spanner slipped out of the grooves. Not sure I would use WD-40.

[Mal Paso]

OK, so mine has not been glued. I am going to try with some WD-40.

Yikes! WD 40 is not a lubricant although it sort of acts like one until the solvent dries.

A drop of 10 wt oil like ATF would be better. ATF and acetone 50/50 is the best penetrating oil period. Automatic Transmission Fluid, not synthetic.

[kunlun121]

Yikes! WD 40 is not a lubricant although it sort of acts like one until the solvent dries.

A drop of 10 wt oil like ATF would be better. ATF and acetone 50/50 is the best penetrating oil period. Automatic Transmission Fluid, not synthetic.

That is a great suggestion, thanks.

EDIT: wait, does it have to be ATF of can it be any 10W mineral (i.e., non-synthetic) oil? Does the stuff they add to ATF make it more suitable as penetrating oil when mixed with acetone?

[jnantz]

... last time I had this problem I shipped the gear back to the seller because neither I nor my repair person could access the shutter to do a CLA ..
before manhandling the lens it might be worth deciding if it is worth damaging the shutter, board or glass ( if things go sideways ).. there's a lot of lenses out there to be bought that might not have this issue ..
that said, if the spanner wrench you purchased doesn't have mass / strength
to transfer your force, SK Grimes sells spanner wrenches that have heft to them, and transfer torque really well..
(as I did ) it might be worth taking the lens to a repair person who might have a bench lens vice .. or at least the right expertise, solvents / routine to do the job without damaging the lens...

[xkaes]

Someone may have put thread locker on the threads or you have a bit of corrosion going on. Using some sort of anti-seize lubricant in small quantities might work. If it's mounted on a lensboard you could put the lensboard in a bench vise to get more leverage.

I'm in a similar situation -- I think someone used some glue to keep a lens on a shutter. I can't get it to budge -- even with a pipe wrench. Take a real close look at the thread on the lens and see if you can spot any glue/goo. If that's the case it might be super-glue or epoxy. There are ways to loosen that. Also check for rust. Report back.

[xkaes]

Yikes! WD 40 is not a lubricant although it sort of acts like one until the solvent dries.

A drop of 10 wt oil like ATF would be better. ATF and acetone 50/50 is the best penetrating oil period. Automatic Transmission Fluid, not synthetic.

Correct. Another option is Liquid Wrench.

[Chuck Pere]

Can't you just unscrew the front and back lenses? That would prevent any glass damage.