How Sump Sludge Harms Your Coolant

Jan 22, 2018
How Sump Sludge Harms Your Coolant

In metalworking, coolant is used to cool down the heat generated by friction between the tool and the metal being cut. It also washes the metal chips and fines away from the cutting tool. The chips and fines follow the coolant to the sump where most settle. An accumulation of chips and sludge formed from the fines can be a big problem for your coolant.

Chips and fines in sumps cause microbial growth. Most chips and fines settle to the bottom of the sump forming a sludge. This sludge promotes bacterial and fungal growth. Biocides added to the coolant to control the growth of bacteria do not reach the coolant that is mixed with the sludge at the bottom of the sump. As the bacteria grows the sump begins to smell rancid.  Employees may get dermatitus, dry, red, itchy skin caused by irritation.

Failure to remove chips and fines can reduce sump volume. Some of the water in water-based coolant is lost by evaporation. Coolant is also lost when it is carried out on parts. Chips and fines settle in the sump, making the sump continue to appear full, even though the volume of coolant moving through the machine has been reduced.

machne tool sump cleaner

A sump cleaner is the best tool for vacuuming sump sludge

machine tool sump Excessive solids can cause increased fluid temperature. Less coolant moving through the machine, means less time spent cooling in the sump. Fluid is pumped back through the machine quicker resulting in higher coolant temperatures. Also, solids have different heat transfer properties than coolant.


Excessive solids may deplete coolant ingredients – coolant is not as effective.   Among the ingredients added to coolant are rust inhibitors, fungicides and biocides, wetting agents, emulsifiers and coalescents. Solids may absorb desirable ingredients and lessen their effectiveness. Many of these problems can be eliminated or greatly reduced by cleaning the sump regularly.

CECOR machine tool sump cleaners deliver high-suction lift to remove all solids in the coolant sump along with the metalworking fluid. The filter separates solids from the coolant for re-use right at the machine tool. Filtered coolant is pumped back into the sump in minutes.

Ninety-gallon, electric sump cleaner



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