Excessive machine coolant loss seems to be due to overuse, splashing or changing it too often.  Take a look at some of our other Articles on Machine Coolant in our Coolant filtration Index.

1.   Overuse typically comes from too high a concentration.  

Premixed machine coolant

There should be two kinds

A.  Start up machine coolant, the kind you use when you change the sump.  This should be 5% to 10% depending on the manufacturer’s recommendation. 

B.  Make up machine coolant.  This should be about 10% of the original machine coolant or about .5% to 1%

We have just done two analyses that illustrates the problems with this. 

In an analysis of company M the concentration was supposed to be 5 – 10% and they wanted 7%.  They actually had 11.78% and 17.05%

In company W they had concentrations of 0.4%, 2.12%, 1.0% and 1.18%.  It should have been 5%.

Both companies sure they were doing things properly because they were using premixed machine coolant as the salesman told them to.  However each company was only using one kind of  premixed machine coolant.  Company M was using start up machine coolant for start up and for make up as well.  It stared out at the right concentration and just got thicker and thicker.  Company W was using make up machine coolant for start up and for make up.  As it got used it got thicker and closer to right but it never did get to the right concentration. 

When machine coolant gets lost out of a machine most of it gets lost as evaporation and almost all of what evaporates is water.   As the water evaporates out the machine coolant gets thicker and more concentrated.   The machine coolant additives such as the anti-bacterial, anti-rust and lubricant also wear out slightly.  

2.  Splashing can be a real problem.  Part of the reason for this is a “more is better” philosophy.  Actually less may be better.  All you really need is a small amount of machine coolant right at the work area where the wheel meets the carbide.  Take a look at our article Getting Coolant where you need it.