On Nov 9, 5:18*pm, Grumpy The Mule wrote:
Well that's sad. *I doubt it's nylon which was invented in 1938,
maybe phenolic? *Wood filled phenolic which swells... ugh!
Maybe you can rinse it with solvent then dry it out so it will
shrink back to nominal dimensions. *The rest of it is constructed
of isolantite and brass which solvents won't hurt.

I have witnessed 50 or 70 year old variable capacitors of
low-to-middle grade construction where I swear it's the metal
that's swelling. The spacers between plates seem to have
expanded or contracted so that while the rotor/stator mesh is centered
at the center of the capacitor, at the ends the rotor and stator are
nearly
touching.

Others tell me this is well-known but I still don't have any
understanding
of why metal would shrink or grow with time.

Tim N3QE