Ultrasonic cleaning is a very good way to get the crud out of sintered bearings. Now that analog turtables and tape recorders are being sought and used again, some AudioPhool boutiques gush about their multi-step ultrasonic cleaning and re-oiling process for motors. Many of those same boutiques are eager to find and use classic Tektronix scopes and Hewlett-Packard signal generators and distortion analyzers. They are also the ones who search for 5XX models at hamfests, take out all of the tubes and the power transformer(s), and throw the rest in the dumpster.
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Bruce Gentry, KA2IVY
On 8/13/19 7:13 PM, Ken Eckert wrote:
I wonder if ultrasonic cleaning would help before relubricating, assuming
the bearing can be removed.....
On Tuesday, August 13, 2019, Bob Albert via Groups.Io <bob91343=
One can indeed relubricate a sintered 'lifetime' bearing. I have been
successful doing it.
The preferred method, time intensive, is to remove the bearing and soak it
in oil for a day or two. It will eventually take in enough oil to allow it
to operate for a very long time.
Another, less effective, method is to drizzle oil on the bearing
repeatedly, like three times a day at first and then once a day. When it
doesn't dry up any more, it should be good to go.
Once you reinstall them, use urdinary lubricating procedure to make sure
they are going well. After having done that, you can leave them alone.
However, if they have been run dry for too long, the pores may have closed
up and won't take on fresh oil. When a bearing starts to make noise, it's
wise to take it out of service. And ignore the 'lifetime' appelation; oil
them now and then.
On Tuesday, August 13, 2019, 02:22:15 PM PDT, Richard Knoppow <
I am not so sure about what additives there are in engine
oil. One can get good quality SAE 20 machine oil at many hardware
stores. 3-in-one puts it up in a blue can (red can is something
else). Also as Kano Microil, very highly refined petroleum based
oil, wax free, and does not gum. Most of these blower bearings
are so called "life time lubricated" meaning it works until it
doesn't. They are made from sintered bronze with oil held in the
spongy metal. You can't really re-lubricate them in any easy way
but they will hold oil for a reasonable time.
Hewlett-Packard used blowers with a rubber seal at one end.
They could be re-lubricated using a syringe to poke through the
seal and inject some oil. I have no idea if the Tek blowers are
similar. Unfortunately, once the bearings run dry they will
become galled and run rough despite having new lubricant.
I agree with you that mixing silicon oil or grease with
petroleum lubricant is not a good idea.
On 8/13/2019 2:03 PM, Chuck Harris wrote:
Silicone oil isn't miscible with the original oil, and
you are not going to make the motor become maintenance
free, no matter what you do with oils.
Just give it some motor oil, thin like SAE5 or 10 is fine.
Detergent isn't like the stuff you wash your clothes in,
it will not cause any problems, in spite of its suggestive
The synthetic doesn't oxidize as quickly as the old oil
did, but then any modern oil is much better in that regard.
The last time anyone lubed your scope fan was likely 40
years ago and yet, it still works. Give it a couple of
drops of oil, and move on... be happy!
Stephen Hanselman wrote:
I've read some of the answers and wanted to add my two cents. We use
mystery oil which seems ok so far. I was thinking about using silicon
gun oil though