Subject: Re: Looking for info on Polyurea based grease...

From: [email-masked] (Jonathan M. Elson)
Date: 7 Nov 1995 20:05:41 GMT

Kevin Pinkerton ([email-masked]) wrote:
: Hi, I was looking for some spindle bearing grease for my milling machine when 
: I came across a product distributed by United Oil Company (Baltimore) called 
: Duralene Dura-Life 1200. I am looking for anyone that may have had some 
: experience with polyurea based grease that can give me some feedback. This is 
: a polyurea based (new generation polyurea) grease, not a soap based grease. 
: The literature says it "heals" (returns to normal consistency) after shearing 
: (whatever that means). It exhibits better water sparyoff (7.7%) than water 
: resistant greases. It contains no metals. The polyurea thickener provied 
: Extreme Pressure properties without being heat activated. It contains more 
: than 90% oil (versus 75-90% oil in lithium and lithium complex greases). It 
: has a 565 degree drop point. The literature lists about 5 more key points that 
: I won't go into here. I am not trying to sell this stuff. Of course the 
: salesman was trying to sell it and made it look like good grease to use in a 
: permanent sealed bearing type application. The spindle bearing cannot be 
: regreased without disassembly. I figured someone in the automotive field would 
: be more likely to have heard of this type of grease before. Thanks for any 
: help/feedback I might get.

Roller (and ball) bearings 'shear' the lubricant, by pressing it in between
the roller and races in a space of about .00001" or less.  If the grease
repairs the damage of shearing, it would be a real advance in lubrication.
Most lubes either resist the shearing or break down, turning into oil.
The high 'drop point' is good, because it keeps the grease in the bearing,
instead of flinging it off.  Some machine tools (like my 1940's Bridgeport)
use UNsealed bearings in the spindle, in which the design of the spindle
keeps most contaminants out of the bearings, but if you take the quill
out, you will see the balls and retainer right out in the open.  I haven't
tried to disassemble my spindle yet, but I probably should.

---

From: [email-masked] (Kevin Pinkerton)
Date: 7 Nov 1995 13:47:20 GMT

Hi, I was looking for some spindle bearing grease for my milling machine when 
I came across a product distributed by United Oil Company (Baltimore) called 
Duralene Dura-Life 1200. I am looking for anyone that may have had some 
experience with polyurea based grease that can give me some feedback. This is 
a polyurea based (new generation polyurea) grease, not a soap based grease. 
The literature says it "heals" (returns to normal consistency) after shearing 
(whatever that means). It exhibits better water sparyoff (7.7%) than water 
resistant greases. It contains no metals. The polyurea thickener provied 
Extreme Pressure properties without being heat activated. It contains more 
than 90% oil (versus 75-90% oil in lithium and lithium complex greases). It 
has a 565 degree drop point. The literature lists about 5 more key points that 
I won't go into here. I am not trying to sell this stuff. Of course the 
salesman was trying to sell it and made it look like good grease to use in a 
permanent sealed bearing type application. The spindle bearing cannot be 
regreased without disassembly. I figured someone in the automotive field would 
be more likely to have heard of this type of grease before. Thanks for any 
help/feedback I might get.

Kevin P.