[Mike Rivers]

On Dec 17, 3:12 am, "Peter Larsen" wrote:

Could it be that they have a one way seal like sealed ball bearings .... one
that allows things in, but not out.

This is one of those things that I've just never seen a need to study
in depth. However, I have been amazed that, when I have a noisy pot
that appears to be sealed, I can shoot a little cleaner toward the
pot, work it in, and it both feels and sounds better. So some of it
must be getting inside one way or another. Maybe it leaches down the
shaft molecule by molecule. Maybe it finds a crack in the case
assembly.

We all know, of course, that a shot of contact cleaner in a pot,
particularly a "sealed" pot, is only a temporary measure. If it's worn
before cleaning, it's still worn, and will get noisy again sooner or
later, mostly sooner. But for all the people who don't want to take
their gear into the shop, it's something they can do at home that will
make them feel like they're fixing it.