I've pulled the faucet apart and in the valve housing, there are two ceramic disks that rotate to mix the hot and cold water. I thought the piece was a single piece until I realized it budged a bit. I was able to slide the two apart in a shearing motion (rather than pulling them directly apart).

I couldn't understand how they were so stuck. I put the pieces together and pulled them directly apart and they were fine. Then I put them together and rotated them (as they would do in the housing) and that's when I could feel them glue themselves together. It dawned on me that the ultra-smooth surfaces were forming a vacuum between them as I rotated them. To the point where i could no longer rotate them at all, and had to forcefully shear them apart again.

This only began happening in the past week. Prior to that, the faucet worked as it always had.

Anyone know anything about what I'm referring to and whether there's any remedy?

  • I think it is actually a capillary bridge rather than a vacuum, and I don't begin to understand it, but here is an article that doesn't make it any clearer to me. en.wikipedia.org/wiki/Capillary_bridges
    – bib
    Commented Apr 14, 2019 at 15:57
  • Yes, probably. But the effect is still that the two disks get stuck together as if they're glued! It's quite amazing actually :) Actually I'm not so sure...if the capillary bridge requires a fluid, then no unless the the fluid is a thin layer of air molecules that is squeezed out upon rotation thus resulting in a vacuum. I really need to just make a video of it! Commented Apr 14, 2019 at 15:59
  • Oh, I mistakenly assumed they were wet. Now I'm not sure, and maybe vacuum is the right concept. Or surface tension? Or microgravity? Or the evil energy controlled by the Dark Force?
    – bib
    Commented Apr 14, 2019 at 16:37

2 Answers 2


Machinists use measuring blocks called gage blocks, whose surfaces are so flat and smooth that you can wring them together and they'll stick tight.

Again, this requires extremely flat and smooth surfaces; this isn't something that would accidentally happen and cause a problem in your faucet. My guess is that the stiffness you feel is somewhere else in the mechanism. (If I'm right, and you figure out where, let us know in the comments.)

  • These ceramic disks are in the micron level of flatness - I'll create a video shortly - and this sticking together is essentially a dry seal for the water flow. So it's exactly what your first sentence is referring to. (oddly enough I'm just watching This Old Tony on youtube and he's just talking about gageblocks lol youtu.be/gZTUFev08H0?t=675 Commented Apr 14, 2019 at 16:45
  • I'm not surprised, but that's more evidence that this isn't a bug, but a feature. Commented Apr 14, 2019 at 17:23
  • Right, it seems that nothing is physically wrong with the components, but then I have to wonder what changed a week ago to make the handle nearly impossible to turn. Commented Apr 14, 2019 at 18:08

So upon further researching, it seems these ceramic disks just sit against each other. I tried dabbing a drop of water between them and that seemed to prevent the binding action that was occurring when they were dry. I reassembled the faucet and it seems to be back to normal, at least for now.


  • This indicates that there was something else that was causing the binding. When you disassembled the faucet, whatever it was got dislodged and was no longer binding when you reassembled.
    – FreeMan
    Commented May 5, 2021 at 17:30

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