It’s all in the name

Dr. Robert M. Gresham, Contributing Editor | TLT Lubrication Fundamentals February 2016

Old habits die hard with the term soluble oil.

I STARTED MY FIRST "REAL JOB" WITH THE DUPONT CO. at the Chambers Works in Deepwater, N.J., with my bright, shiny new doctorate literally in hand. I say literally since they actually photographed it. Anyway, I was confronted by a series of new but not recognizable names for things otherwise familiar to me. Some of the more notable were 2B Alcohol, Tolyene and, having just gone to school in the South, a favorite to my sweet, Southern accent tuned ear was Wuddereyece. Or at least that is what it sounded like to me. When my technician, who was born in South Jersey, used these terms, I gave him that deer-in-the-headlights look of total and absolute incomprehension. This prompted from him, “Ey, man, I tawt you hadda Ph.D.! Don’t youse know nuttin’?” Ahh, no, apparently I did not—at least in that context.

Most of my experience was with reagent-grade solvents and materials from companies like Fischer Scientific, Eastman Chemical and the like, not with commercial-grade materials, either with different names or carrying names by custom of the inmates at the Chambers Works. So 2B Alcohol was in fact what I had called Absolute Alcohol, which is anhydrous (no water). However, it did contain 2% benzene as a contaminant as a consequence of distilling off the water—hence the 2B. Tolyene was South Jersey for Toluene. I’ve not figured the why of this one, unless there is something mystic or unpronounceable about words that contain “ue.” 

However, my all-time favorite, as you might guess, was Wuddereyece. When I asked my technician for “aahhce” (remember in those days I had a Georgia-style Southern accent), what I got was the question, “Youse mean wuddereyece?” This, I somewhat later learned, with much head-shaking and similar negative body language, was to mean “water ice.” And why water ice and not just ice (or aahhce as properly pronounced)? These other worldly denizens differentiated water ice from dry ice or frozen carbon dioxide. It is simple enough once you know the names and practice the pronunciations.

These examples bring me to the point of the article. In one of our Certified Metalworking Fluids Specialist™ certification subcommittee meetings, we got into a minor snit over the use of the term “soluble oil” in the stem of one of the exam questions. As it happens, the term soluble oil has been around for a very long time in the metalworking industry, and it has definite meaning to the user or practitioner of such metalworking fluids (MWFs).

As early as 1883, Frederick W. Taylor (see Figure 1), who later in 1911 became known as the father of scientific management in steel mills in Bethlehem and Philadelphia (I guess he was the first true Certified Lubrication Specialist™), began experimenting with water as a metalworking cooling fluid. He discovered one of the metalworking industry’s holy dictums: Keep the tool/workpiece interface cool, and the tool will cut better and longer. While he probably didn’t know it, water’s high heat of vaporization does indeed make it ideal as a coolant. Over time they also discovered that lubricating this interface also contributed to the quality and quantity of metal removal by the cutting tool. So with the development of colloid and surface chemistry science, chemists learned to emulsify lubricating oil in the cooling water to make a stable coolant with lubricating properties. For you nonchemical types, an emulsion is a stable form of an oil (hydrophobic) material in water. Milk is one of the most common forms of an emulsion. The milk is made stable by naturally occurring surfactants (which are kind of like soap). Equally, in in industry, oil-in-water emulsions are made stable, in part, by proper use of surfactants.


Figure 1. Frederick W. Taylor experimented with water as a metalworking cooling fluid. (Photo courtesy of Explore PA History, http://explorepahistory.com/hmarker.php?markerId=1-A-251.)

Once again getting back to the point, these early folks characterized these emulsions as soluble oil. However, this was in fact a misnomer. In a true solution, the oil would have to dissolve completely into the water resulting in a clear, perhaps slightly colored liquid, which is quite stable. True emulsions are opaque or perhaps somewhat translucent but otherwise quite stable unless you do something to upset the surfactant system used to emulsify the oil. For example, if you add vinegar to milk, you break the emulsion and make buttermilk. Thus, it was this stability that resulted in the term soluble oil as it was as stable as if the oil was dissolved in water, thus soluble oil.

A century later we find all manner of colloids, emulsions, dispersions and suspensions around us in foods, cleaners, cosmetics, paints and most certainly MWFs. With the development of synthetic lubricants for MWFs, which can be true solutions, we have now introduced genuine ambiguity in our use of language, as these synthetics are truly soluble oils, not emulsions. But old habits die hard, and the term soluble oil is still used in many plants today.

For the certification team, this poses a problem, especially when one considers that an individual taking the exam might be from another country whose use of language might not even include the term soluble oil. Indeed, any such certification exam question about the use or composition of soluble oils could be interpreted just as easily to be an emulsifiable oil. No proper certification question should have any ambiguity regarding what is being asked.

So STLE’s MWF Certification Subcommittee spends much of its time carefully crafting its questions to remove doubt about what is being asked. Likewise, STLE’s MWF Education Subcommittee has been meticulously vetting its presentations to teach these differences in custom and terminology and to help encourage the proper use of the term emulsifiable oils instead of soluble oils.

Indeed, the STLE MWF Education Subcommittee will be presenting its outstanding two and a half-day certificate course on Feb. 23-25 at the Sheraton Suites Philadelphia Airport. The course will include not only sage-on-the-stage presentations by experts but also interactive case histories, learning games and a brief test at the end covering the material presented. Those passing the test will receive a special certificate.

This course is ideal for those reviewing and preparing for the Certified Metalworking Fluids Specialist™ certification examination. For more information on either the course or the certification examination, go to www.stle.org or send me a note at rgresham@stle.org.


Bob Gresham is STLE’s director of professional development. You can reach him at rgresham@stle.org.