Lubricants and Coolants – “Vanishing” Oils?

“Vanishing Oils” are often considered as an alternative to more conventional lubricants in light duty stamping and forming operations.  The conception is that these formulations actually “vanish” eliminating the need for cleaning once there is no longer a need for lubrication.  True, depending on circumstances, they may reduce or eliminate the need for cleaning but in fact, they do not “vanish.”

Vanishing oils are formulations of oil and volatile components, usually solvents.  The actual lubricant is present as only a very small portion of the overall mix with the volatile component or components comprising the bulk of the formulation.  If you will remember, in an earlier blog it was stated that in most applications, especially in applications involving stamping and drawing, lubricants are vastly over-applied.  A “vanishing” formulation, although it may be applied similarly to a straight lubricant as far as the actual quantity is concerned, actually only provides a small, but adequate, amount of the actual lubricant.  The other components evaporate before or after the process leaving only an often non-detectable amount of lubricant.  In some cases, the volatile components may contribute to the lubricating properties of the formulation, but, somewhere in the mix, there has to be a lubricant with the properties we have discussed in preceding blogs (search Lubricants and Coolants).

Do vanishing oils eliminate the need to clean?  In some cases yes, while in others the answer is no.  If a completely hydrophilic surface is the criteria for cleanliness, the answer is, most probably, a simple NO.  But, in many cases, especially on parts subject to corrosion, the residue of a vanishing oil may be beneficial.  Oils prevent corrosion by preventing oxygen and moisture from reaching the surface of the part.  They are great rust preventatives.  If a rust or corrosion preventive formulation would be required anyway, a vanishing oil may provide a win-win.  With conventional (non vanishing) lubricants, a cleaning step is frequently required to remove the excess lubricant residue after processing and prior to the application of a controlled amount of an oil-based corrosion preventing formulation.  Oil based corrosion prevention formulations are, in fact, very similar to vanishing oils.

In summary, even if a corrosion preventive is not required, parts that don’t require a hydrophilic surface may be processed successfully using a vanishing oil.  Parts that require corrosion prevention may be processed successfully using a “vanishing” formulation provided that the oil residue once the bulk of the formulation has vanished is of the proper type to act as an effective corrosion inhibitor.  Parts processed with vanishing oil but that still require a hydrophobic surface will, likely, still require cleaning.

Vanishing oils are not a universal solution to any problem but, if used wisely, can eliminate processing steps and minimize effluent streams requiring treatment for oil content.

–  FJF  –