john wrote:
Michael Koblic wrote:
LMS recommends Mobil 1 for lubricating mini-mills. I picked up a
bottle of 5W-30 and have been using it. I noticed that the oil does
not stay on the dovetails very long and tends to pool on the bench.

In my simple mind I thought: Higher viscosity is needed, something
like 20W or so. That is where I got confused: I looked up the
figures for Vactra 2 (being the industry standard for ways etc.).
Its kinematic viscosity at 40 deg C is 68 cSt (ISO68). When I looked
at the 5W-30 the viscosity was almost exactly the same. I thought
this might be an error on the Mobil page but no, a similar result
came up for 5W-20. To puzzle me further, the 10W-30 is somewhat
thinner at this temp. The tables at my disposal suggest that the 5W oils
should be under 20
cSt at 40.

Before all this I bought a bottle of 15W-50 which was on sale
locally. According to the tables it should be somewhere near 45 cSt
but according to the Mobil product sheet the 40 deg C viscosity is a
whopping 131 cSt - about half way between Vactra 2 and Vactra 4.

What am I missing here? Is this comparison at all valid?



Automotive detergent oil will screw up the felt wicks that are used in
many machines. It will make them stiff and move the oil. Also the
detergent oil will tend to carry the grit in suspension rather than
letting it settle out.

The Vactra way oils have an additive to make the oil adhere to the
ways, the same function as the additive in chainsaw bar oil. Vactra
2 is what is mostly used on ways.


John

Lucas brand synthetic gear oil stays put , lubes well , and is available
almost everywhere (well , everywhere in the USA) . I use it on leadscrews ,
ways , gears , and countershaft bushings on my mill and lathe both . Kinda
pricey though , about 7-8 bucks a quart .

--
Snag
"90 FLHTCU "Strider"
'39 WLDD "PopCycle"
BS 132/SENS/DOF