I’ve been reading about the recommended maintenance and wanted to make sure I had the necessary lubricants on hand. I ordered some Vactra #2 Way oil from Amazon, which is recommended. What I received has a label of Mobil Vactra #2, but the safety sheet that came with it says it’s intended as hydraulic fluid. It also identifies it as Mobil Velocity Oil No. 10.
Before I ever use it, I wanted to make sure I have the right lubricant. On a previous CNC machine I had, I made the mistake of using the wrong one and it took a long, long time to get it back into working order due to the difficulty in removing the incorrect one and getting the correct one to replace it. It didn’t help that disassembling the affected parts wasn’t really possible for the tools I have, not having a full machine shop available to me.
My bottle of Mobil Vactra #2 is dark brown. I found that this is sometimes referred to as Bridgeport Oil. I think they use the Mobil Vactra #2 as lubricating for old Bridgeport machines. The oil seems rather heavy like a 40-60 weight oil. I think the dark brown color comes from the additives they put in for the lubrication properties and corrosion.
The Mobil Vactra™ Oil Numbered Series are premium-quality slideway lubricants specifically designed to meet the requirements for accuracy, aqueous coolant separability, and equipment protection of precision machine tools.
The Mobil Vactra Oil Numbered Series is carefully formulated from high-quality base stocks and performance balanced with an advanced additive system that provides controlled frictional properties, compatibility with aqueous metal working fluids and corrosion protection of parts and equipment. The unique additive package provides exceptional frictional properties on a wide variety of way materials, including steel on steel and steel on polymer, reducing stick-slip and chatter. This allows smooth, uniform motion at design travel speeds enhancing machine productivity and accuracy helping to prolong tool life and enhance surface finish. The Mobil Vactra Oil Numbered Series has been optimized to provide separability from many aqueous coolants while minimizing the corrosive effects of high pH coolants on lubricated surfaces.
Additional Info:
ISO Viscosity Grade 68
Here is a picture of the Mobil Vactra #2 Gallon size, notice the dark color.
My guess is the vendor included the incorrect data sheet. I’m adding a picture of the label on the container I received. You can see from just outside the label the liquid is dark brown. I was just surprised at how thin it appears to be (about the viscosity of 3-in-1 household oil, which is pretty thin), just from tipping the bottle and following the air bubble.
My understanding is the big difference for Vactra No. 2 is that it includes “tackifiers” which will hold it in place on vertical and horizontal surfaces (for a while — it’s intended for machines which are used regularly).
There’s been some lengthy discussion on other forums — I believe most would characterize our sticking w/ it as a conservative choice driven by the proportion of customers who don’t use their machines as often as would be best.
