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New oil for gummy 60 year old sleeve bearings

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
I have inherited my father's Dumore tool post grinder. He had not used it for the last 50-60 years. This has oil cups or holes on the motor and arbor so I assume sleeve bearing. I would prefer not to take it apart. I said gummy but the bearings actually feel fine I just know they have dried oil in them.
My plan was just to fill every hole with new oil and refill a few days latter, spinning by hand to distribute the oil. Hope that will dissolve and flush any gunk. He put very low use on the machine. it looks brand new.
Should I maybe oil with a solvent first like paint thinner or even carb cleaner. No plastic to worry about.
Bill D
 
Just light machine oil ( like "3 in 1" oil) refill often for a couple of uses. You'll be good to go. Flushes out the gunk and keeps the bushings lubed. You don't want to dry them out as that can actually make the gunk harder and more difficult to remove. ( Been there )
The only way to use a chemical cleaner reliably for such a cleaning is under total disassembly.
 
My DoAll blade grinder attached to my bandsaw has this problem. The bearings are gummy enough that when you push the start button, the motor barely rolls....so you help it by hand and it slowly picks up speed until it reached full RPM. Then, it's fine. I've added lot of oil over time in hopes will un-gummy itself but it never has. I mean, it will start 'better' for a little while then the gummy comes back. I finally decided that the best course is for me to leave it alone and to vow to endeavor to persevere.
 
I have inherited my father's Dumore tool post grinder. He had not used it for the last 50-60 years. This has oil cups or holes on the motor and arbor so I assume sleeve bearing. I would prefer not to take it apart. I said gummy but the bearings actually feel fine I just know they have dried oil in them.
My plan was just to fill every hole with new oil and refill a few days latter, spinning by hand to distribute the oil. Hope that will dissolve and flush any gunk. He put very low use on the machine. it looks brand new.
Should I maybe oil with a solvent first like paint thinner or even carb cleaner. No plastic to worry about.
Bill D
Kerosene or Diesel is good as both a solvent & lubricant in situations like this. Flush repeatedly and run briefly before putting proper oil in
 
I roughly agree with the above posts, but I would not run it up to speed until it was well loosened up. Hand spin it quite a number of times before full speed.
The old-fashioned 3 & 1 oil is a pretty high-grade 20 wt oil.
Guess if I used a solvent like Kerosene or Diesel I might go 50-50 with 3 & 1
And check the motor for an oil port/ screw (?).

Wow, just down the road from me an ID spindle,
 
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I once left the DoAll grinder motor running for 24 hours...I figured it would heat up good and plenty and fix itself for sure. The next day...Gummy City.
 
Kroil will cut through dried oil in short order. Far better and less destructive than carb cleaner, etc. in my experience. (A little paint bucket partially filled with it works great in combination with a brass brush as a poor man's parts washer.)

The trouble as touched on above is that Kroil has volatile petroleum distillates in it and will itself dry out in short order if it is not flushed back out within a day or two. It's not a fantastic lube oil. Only designed for the initial cracking loose of stuck things and protection from rust. Beyond that it will dry out and leave a waxy film behind. Hence the need to disassemble the spindle unless you can pressure-lubricate the thing to force the used Kroil (and dissolved gunk) back out with proper machine oil.

Or as suggested above, just lubricate the thing with regular machine oil on a frequent basis to gradually dissolve the dried stuff over time. Oil it, turn it around by hand until it's loose, then run it for a minute or three. Let it sit for a day, then wash, rinse, repeat. Assuming there are no seals on the shaft, you'll see a little more of the old crud get flushed out each time you come back to do this again. This method won't get all of it, but it will clear the bearing interfaces.
 
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*QT Sparky "Assuming there are no seals on the shaft,"
Very / very important with considering solvents on any device..
Just plastic bearing shields must be considered.

QT: (gummy 60-year-old sleeve bearings) I don't think that it has sleeve bearings.
 
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I have used Marvel Mystery Oil for stuff like this too and it worked. Just don't run it permanently.

I know of a large sawmill that hired a new head of maintenance. He put MMO in everything and about 6 months later equipment was dying left and right. The MMO is a better cleaner than a lubricant I guess.
 
I flushed out the seized quill of a bpc with sea foam into the oil cups. After quill worked free and the run off was not gritty swapped out for oil. Still free a few years later. It is smoother now than it was years before that.
 
*QT Sparky "Assuming there are no seals on the shaft,"
Very / very important with considering solvents on any device..
Just plastic bearing shields must be considered.

QT: (gummy 60-year-old sleeve bearings) I don't think that it has sleeve bearings.

Well if the thing has seals then a rebuild is in order, period. Adding oil to a sealed system with dried oil already in it will result in a blend of thickened oil and wax. Not good for a high speed grinding spindle. Flushing with fresh oil only works if there is a way for the old crap to squeeze out.

Edit:

No idea what grinder the OP has, but this exploded view shows metallic shields, not seals:

https://www.dumoretools.com/parts/series-12-25/external-spindle-8-inch
 
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The spindle has an oil cup with spring loaded lid. The motor has big oil holes at each bearing. I doubt it would be sealed with open holes for oil.
will look up the model number and report what I find as far as shields. I belive it has a 1/4" spindle for the grinding wheels so a small machine designed for a 9" lathe
Bill D
 
Well if the thing has seals then a rebuild is in order, period. Adding oil to a sealed system with dried oil already in it will result in a blend of thickened oil and wax. Not good for a high speed grinding spindle. Flushing with fresh oil only works if there is a way for the old crap to squeeze out.

Edit:

No idea what grinder the OP has, but this exploded view shows metallic shields, not seals:

https://www.dumoretools.com/parts/series-12-25/external-spindle-8-inch
At those rotational speeds, the seals would catch fire.
 
I have used Marvel Mystery Oil for stuff like this too and it worked. Just don't run it permanently.

I know of a large sawmill that hired a new head of maintenance. He put MMO in everything and about 6 months later equipment was dying left and right. The MMO is a better cleaner than a lubricant I guess.
That's why I suggested Marvel Air Tool Oil as it has some of the properties of MMO but also lubricates.
 
On the subject of old motorized devices, the ability to Ground is very important.
Some old devices did depend on being attached to a grounded machine to achieve the sufficient electrical ground. Such a device is not safely grounded when not attached
So by habit or caution, one must always consider that such a device can be hot/dangerous when separated from the grounded machine. The best solution would be to add a wire that accommodates/has a grounding wire.
 
On the subject of old motorized devices, the ability to Ground is very important.
Some old devices did depend on being attached to a grounded machine to achieve the sufficient electrical ground. Such a device is not safely grounded when not attached
So by habit or caution, one must always consider that such a device can be hot/dangerous when separated from the grounded machine. The best solution would be to add a wire that accommodates/has a grounding wire.
Yes. Always add a frame ground wire. Then, if a winding shorts to the frame, it will blow a breaker, versus the operator.
 








 
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