I have a B+W Filter 77mm HTC Cirular Polarizer Nano KAESEMANN XS-Pro MRC. It has become so stiff to rotate that I basically can't use it anymore. I'm assuming some dirt has gotten into the threads. How can I clean this properly, without damaging it?


1 Answer 1


I see three possibilities, not all of which might be DIY
In terms of delicacy vs price, that's right up there in the "I really ought to take it to a pro" stakes.

  1. Dirt has got in it.
    Well, basically, it's made of metal & glass, so as long as you don't drown it, a touch of WD40 might ease it. Spray it onto another surface not onto the filter itself & use a cocktail stick to put the tiniest amount into the joint. Any slight leakage to the outside should be cleanable - inside, not so much.
    I'd advise against anything more invasive. It might physically survive a rinse under the hot tap, but you may never get the inside clean & dry ever again.

However, my money would be on…

  1. It's no longer flat.
    Test by placing it on a dead flat surface, maybe a mirror, & see if there's any movement/rocking/visible gap. If it's distorted you'd have to weigh professional intervention against how gently you might try to rectify that.

  2. It's no longer circular.
    You can try gently squeezing it from the edge, turning slightly each time to see if it frees up with pressure in one direction, but I doubt that's a DIY fix at all. Take it to a professional.

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    \$\begingroup\$ WD40 is not a lubricant. It is a Water Dispersant. After it dries, the ring will probably stiffer than it was at the beginning. A non-dripping lubricant, such as white lithium grease will be much more effective. \$\endgroup\$
    – Michael C
    Oct 25, 2019 at 6:34
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    \$\begingroup\$ Myth - WD40 is not a lubricant I doubt any grease would be thin enough to penetrate such a narrow gap without heating. \$\endgroup\$
    – Tetsujin
    Oct 25, 2019 at 6:43
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    \$\begingroup\$ Anything that is made up of 50% mineral spirits, as the makers of WD40 freely reveal, will eventually break down whatever trace of lubricants it contains. It doesn't take that long. Squeaky door hinges sprayed with WD40 are usually quiet for a day or two, but by the third or fourth day they are squeaking worse than they were at the start. Also, anything that will flow/drip at room temperature will eventually wind up between the filter's glass layers. \$\endgroup\$
    – Michael C
    Oct 25, 2019 at 6:50
  • \$\begingroup\$ Points… 1) No, the remaining lubricant does not evaporate in the short-term, it's good for a year or more. 2) If a door squeak returns the hinge still contains particulate matter you failed to flush. I didn't recommend flushing the joint in this case because of the potential for 3) In small enough quantities it requires capillary action to spread, gravity alone will not do it, so will not run in between the glass layers unless you over-do it initially, hence the cocktail stick. \$\endgroup\$
    – Tetsujin
    Oct 25, 2019 at 7:02
  • \$\begingroup\$ You'd assume a lubricant-dissolving spray to be good at turning seized lubricant into marginally effective unseized lubricant soup :) \$\endgroup\$ Oct 25, 2019 at 10:47

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