Protecting your coolant and machines: Key considerations during a shutdown
When machines sit idle for an extended period of time, measures should be taken to ensure that the coolant doesn’t degrade, and that the machine is protected from damage. There are a variety of ways that being shut down can negatively affect the coolant and the machine: corrosion, biological growth, and emulsion split to name a few.
You should consider performing specific actions to help prevent these detrimental consequences in order to protect the health of the coolant and your machine.
Step 1: Prior to Shutdown
Drain The Sump
If it is possible, one of the best measures for protecting your fluid and machine is to drain it. Draining and cleaning the sump with a sump cleaner will offer the best way to minimize the need for hands on maintenance of the fluid during a shutdown.
If it is not possible to drain the sump it is best to follow the protective measures such as those outlined below.
Remove Tramp Oil
When a machine is shut down for an extended period of time tramp oil in the fluid will separate and float to the surface. This seals the fluids off from the air which will cause anaerobic bacteria to grow due to a lack of oxygen. With any extended shutdown, the oil should be allowed to float to the surface and then removed with an oil skimmer or shop vac.
Make sure that the coolant concentration is within the recommended range to provide pH stability, bio-resistance, and rust protection during the shutdown.
Remove as many chips as possible from the workspace, conveyors, chip pans, sumps and separators. Chips that are allowed to sit over an extended period of time provide an environment where bacteria can flourish and may also cause rusting and pitting.
Step 2: During the Shutdown
Circulate Or Aerate The Coolant
As mentioned, anaerobic bacteria thrive in an oxygen-free environment. Regularly circulating the coolant will ensure that the coolant will aerate and be exposed to oxygen, helping to alleviate these bacteria from growing. Though it is best to circulate the coolant you can also provide aeration with pumps and hoses to bubble air through it.
Open Machine Doors
Consider Adding a Rust Preventive
If a shutdown of longer than two or three weeks is expected, consider using a rust preventive to provide extra protection against rusting.
Even during a shutdown, concentration should be checked regularly to ensure the coolant remains in the recommended range.
Make Sure Workers are Kept Safe
Currently there are not complete and up to date testing procedures and information regarding the COVID-19 virus’s sustainability in metalworking fluids. Until the CDC is able to provide information regarding the specifics of how fluids may be affected there are steps you can take to properly handle potentially contaminated metalworking fluids.
Below are some precautions based on the CDC's guidelines for minimizing the virus’s spread and OSHA/HHS guidelines for cleaning and safety measures:
- If any worker is suspected of or has contracted the virus who has come in contact with specific machines or their metalworking fluids use PPE (Personal Protective Equipment) such as non-porous gloves, face masks, face shields and any other recommended safety gear to ensure the fluid is safely removed from the machine. The fluid must then be disposed of by following the local municipal guidelines for waste treatment.
- The machine should be cleaned by draining the entire system’s tanks and removing all debris from return trenches, oil pans, sumps and filters. Then fill the system or tank with water and circulate it through the machine and lines. Next add a sump cleaner as recommended by the machine manufacturer’s guidelines.
- Do not add bleach or other disinfectants to the metalworking fluid as this can cause potential issues such as machine and part corrosion, chemical reactions, odor concerns and dermatitis.
- Refer to the CDC website for additional information regarding general environmental cleaning and disinfection recommendations.
Keep your equipment and personnel safe so you can be up and running once things get back to normal.
Be well & stay safe!