would be interesting to submerge a "sealed" pot in a liquid and see if the pot eventually fills up, just as an experiment to see just how well these sealed pots are sealed.
Some time ago I had to submerge an unobtainium unsealed pot into a beaker of IPA in order to free the shaft's rotation. It took a couple of days of immersion to free up the shaft. I'm guessing that a "sealed" pot would take much, much longer to absorb the fluid.
DaveD
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On 4/16/2019 1:51 PM, Richard Solomon wrote:
My foolproof method is to drill
a small hole on the top side at
the rear. Pump in De-Oxit Fader
Lube and seal the hole with some
black tape.
73, Dick, W1KSZ
On Tue, Apr 16, 2019 at 10:45 AM Terry Gray via Groups.Io <tlgray42=
[email protected]> wrote:
I also have restored 100's of "sealed"? noisy controls by pointing the
control shaft straight up vertically, wrapping something around the bottom
of the control to catch the excess contact CLEANER/LUBE, spray around the
base of the shaft where it goes into the control, and "pump" the shaft up
and down and give it time to "pump" the contact cleaner/lube down into the
control---remember patience is a virtue. If at first it doesn't seem to be
getting the spray down the shaft, make a dam" just below the point where
the shaft enters into the control and try spraying a little additional
cleaner/lube into that area keeping it saturated and at the same time
periodically "pumping' the shaft up and down to allow the cleaner/lube to
migrate along with capillary action down the shaft. Allow the potentiometer
shaft to remain pointed up vertically. Sometimes it can take overnight or
longer to get the cleaner/lube down into the control but I have found over
the last 50-60 years that it very, very rarely fails. Just be patient and I
think this will work for you, even for the difficult ones. I remember
setting upright on their backs some of the big monster stereos and doing
just that, especially when the potentiometer access was not readily
accessible even with the long extended flexible tubing that sometimes came
with the contact cleaner/lube or that were also available at the time. I
also remember running into some well sealed potentiometers and TV tuners
that we had to drill a small access hole into/through the metal or plastic
housing to get the cleaner/lube inside to do its job. Just be very careful
to not drill into the tuner or control doing any internal damage. I
remember disassembling throw-away pots and tuners to learn where to drill
the holes to prevent any internal damage and you could then seal the hole
up with solder or glue when you completed the cleaning/lube process. One
additional point, DO NOT use a contact cleaner with no lubricating agent in
its ingredients. Many years ago I attended a Channel Master seminar on
their contact cleaners and tuner (and switch) cleaner/lubes. The company
representative showed us under a fairly high-powered microscope a video of
what happens when you spray a contact cleaner (with no lube) on the old TV
tuner switch contacts You completely wash away all lubrication from the
individual contact points and he showed us under the microscope what
happens when you rotate the switch thru the washed contacts. It scrapes the
plating off the contacts and now being unplated in that area it is oxidizes
and you end up with intermittent high resistance contacts down the
line(with time) that play havoc with your circuit. You think that you are
"fixing" the intermittent switch contact(s) (or the intermittent internal
potentiometer wiper problem) but in reality you are totally ruining (for
the future) whatever you are so-called restoring by using a non-lubricated
spray. I wish the video that the Channel Master rep showed us was still
available>>>>it looked like a chisel scraping the plating off the contact
under the high-magnification microscope when all the lubrication had been
previously "cleaned" off the contact areas. He said DO NOT EVER use a
contact cleaner that has no lubrication in it or at least follow up the
"cleaning" process by spraying or adding some additional lubrication to the
contact points. Hope this is helpful information to some of you, it sure
was for me.
On Tuesday, April 16, 2019, 9:51:07 AM CDT, Bob Koller via Groups.Io
<testtech@...> wrote:
Try it sometime, I have literally done hundreds this way. Some last week..
