How to Get Rid of Microbes in Your Sump

Bacteria or Fungus in the Machine Sump

At some point, your metalworking fluid will go bad. Hopefully, in most cases it has ran through its effective life and can safely be removed or recharged with a fresh batch. However, sometimes a fluid’s life will be cut short due to unforeseen circumstances. This may involve machine leaks, breakdowns, or outside contamination. In some instances, your fluid and machine may be filled with bacteria or fungus. When this happens, it is imperative to stop operations and remove all fluid from the sump to prevent any further issues.

If there is any remaining contaminated fluid still in the machine, it will decrease the life and effectiveness of the new charge as the fungus and bacteria will continue to thrive in the existing fluid. It is best to also run a cleaner through the machine to help clean hard-to-reach areas such as pumps and hoses. In addition to cleaning out the contaminated fluid, the cleaner removes process oils, gummy deposits or oil, grease, swarf and other outside contaminants. Monroe Fluid Technology’s Astro-Clean A contains special additives designed to render the machine neutral of bacteria and fungus.

Bacteria and fungi grow in the presence of increased surface area in a fluid. As more bacteria and fungus are in the machine, the faster the growth. This exponential growth problem can wreak havoc on your machine and lead to serious problems. That is why it is important to be proactive in managing your fluid. This will lead to reduced down time and increased performance. The main component of fluid maintenance is following the manufacturers recommended concentration and regularly checking the fluid and adding any additives necessary to maintain the highest performance.

Biocides and Metalworking Fluid Additives

One key additive is biocide. Biocides are designed to kill bacteria, fungus, and other living microbes that will damage the fluid. These additives can simply be added to any sump or central system. Grotan is designed specifically for metalworking fluids to extend fluid life. Grotan is meant to be added at 0.15% (1500 ppm) and will fight bacteria and fungus. Many products are formulated with a biocide, like Grotan, to help protect machinery, tools, and work pieces.

Metalworking fluids with biocides are constructed with recommended concentrations in mind. This matters when a machine may be running “lean” on a fluid. If the manufacturer calls for 4%, but the machine is running at 2%, the machine only has half as much additives as needed. There must be a minimum level of biocide present in a solution in order for it to be effective. If there is not enough biocide, the bacteria will not disappear and slowly but surely repopulate. Therefore, it is imperative to follow manufacturer guidelines to enough there is enough biocide and other additives in your solution.

To ensure proper performance, it is important to regularly check the concentration of the solution to ensure the product performs as expected. Using refractometers to measure the Brix/concentration is crucial in maintaining an aqueous solution. This allows users to see the exact concentration and make adjustments as necessary. It is recommended to record the concentration level daily. Due to water evaporation, it is important to add concentrate to your sump to maintain recommended concentration. Never add just water or concentrate, it is recommended to add both to maintain the sump for longer tool life. Mixers are recommended to ensure consistent refills and measurements.

Cleaning Best Practices

It is also important to hand-wash/hand-wipe reachable areas of the machine to remove any solids from the sump. If these solids are not removed, it can result in continued growth of fungus or bacteria. Fungus typically grows by attaching itself to a solid in the sump or system. Theses solids may be outside contamination or smaller clusters of fungus. Therefore, it is crucial to remove solids and deposits before AND after running a cleaning solution through your machine.

If you are unable to dedicate a time to clean and service the machine, the cleaner can be added to the metalworking fluid solution at a concentration of 1-3%. This allows for cleaning while machining parts. Build-up will release from the machine as production continues. It is important to remove these residues and solids after the system is drained. As new fluid flows through the machine after recharging, some deposits may dislodge and appear in the sump. This is normal and should occur during the first week of a new charge.

Contamination that Grows Bacteria and Fungus

In addition to using a cleaner after draining the sump, it is important to follow fluid maintenance best practices. For example, it is recommended to have some method of skimming tramp oil. This can be done by hand or by having an oil skimmer installed in your tank or sump. When tramp oil gets into the mixture, contaminants from the oil can become “food” for bacteria. The tramp oil will also sit on the top of the sump and provide a “seal” which will allow anaerobic bacteria to thrive and multiply. This results in rancidity, which can create less than ideal work environments.

Sometimes outside contaminants can get into the sump and can create surface areas for bacteria and fungus to attach themselves and grow. This build-up can lead to dead zones in the machine where fluid flow is limited or halted completely. It is important to have mechanisms in place to regularly remove solids from the sump. Some examples of tools include: magnetic wheels, conveyors, and indexable filters. In the case of fungi, the fungal mass will remain in the system since it will not disintegrate in the fluid. Therefore, it is important to remove any fungal mass to prevent future growth. Having these items in the machine allow for solid removal and higher performing fluids.

Twin Specialties Can Help

If your sump is filled with harmful microbes, we are here to help. Twin Specialties has a variety of products and resources available to help get rid of microbes. We offer cleaners and biocides that can be incorporated into your sump and metalworking fluids. Contact us for a coolant management guide, a site visit, or fluid testing. We can discuss how to fix your sump and establish practices to uphold the integrity of your metalworking fluids.

What is Moly?

What is Moly?

Molybdenum Disulfide, simply known as Moly, is used both independently as a dry lubricant and as an additive in lubricating greases. Dry lubricants reduce friction between two sliding surfaces without the need for an oil medium. Dry lubricant molecules have a natural attraction to metal and adhere themselves to metal surfaces. These molecules create a layer of protection that prevents wear and tear as well as significantly improve lubricity of metallic surfaces.

How Does Moly Work?

When used on its own, Moly is impregnated into the surfaces of metal parts to improve the lubricity and protect the parts themselves. When used in greases and lubricants, the Moly attracts itself to the metal surfaces as an anti-wear surface coating. When used in lubricants, Moly’s efficacy is limited if the additive remains suspended. It is important to ensure that the Moly is compatible with the oil or grease. If it is not compatible, the compounds could drop out and plug oil passages and filters.

Moly has a variety of unique properties that distinguish itself from other solid lubricants and solid additives. These include:

  • An inherently low coefficient of friction
  • Strong affinity for metallic surfaces
  • Film forming structure
  • Stability in the presence of most solvents
  • Effective lubricating properties from cryogenic temperatures to 350 C in air
  • Efficacy in vacuum and aerospace applications

Moly Greases

Moly greases can have concentrations from anywhere from 1 to 20%. Typically, Moly greases typically contain 3 to 5% Moly. Moly greases are generally used in operations where high pressure metal surfaces are sliding against each other. These include roller bearings that have very heavy loads and shock loading. Moly greases are also recommended in slow or oscillating motion that is used in universal and CV joints. Moly greases used in high-speed bearings can create problems such as “skidding,” where a bearing roller fails to rotate a full 360 degrees.

Due to its lubricating abilities in vacuums, Moly and Moly greases are popular in aerospace applications. Temperature limitations for Moly are much higher in space (1200 C compared to 350 C in air) thus can withstand extreme temperatures in space. Moly is used for low speed systems such as solar array drives, sensors, and antenna scanners.


As a solid lubricant, Molybdenum disulfide (Moly) serves as a better lubricant and additive than graphite because of its ability to operate under very heavy loads and in vacuum environments. If your machine’s manual calls for a moly grease, it is important to ensure a moly grease is used and the moly grease is compatible with other lubricants in your equipment.

What are Friction Modifiers?

What are Friction Modifiers?

Friction modifiers are mild anti-wear additives used to minimize light surface contact, such as sliding and rolling. These can also be referred to as boundary lubrication additives. These additives are used in lubricants to modify the coefficient of friction (hence the name, Friction Modifiers). Friction modifiers are deployed to prevent wear on metal surfaces. Mostly used in transmission fluids and engine oils, these additives help slow down wear and increase fuel economy.

How do Friction Modifiers Work?

Source: Machinery Lubrication – Noria

A friction modifier molecule consists of two parts: a polar end (head) and an oil-soluble end (tail). The head attaches itself to the metal surface to create a cushion for the metal surface against another metal surface. The tails stand up like a carpet; vertically stacked besides each other in a Nano-sized sheet covering the metal surface. These molecules hold up when cushioned surfaces come in light contact with each other. This forms a thick boundary film that is softer than metal surfaces.

These additives have multiple functions beyond friction modification. They work as antioxidants and corrosion inhibitors as well. As the contact or load becomes heavier, the polar molecules are brushed off, thus rendering the additive useless in reducing friction.

Friction Modifier Applications

Friction Modifiers are typically used in engine oils and automatic transmission fluids. In engine oils, friction modifiers are deployed to improve fuel economy by reducing friction. In transmission fluids, friction modifiers are deployed to improve engagement on clutches. Some situations require some traction to operate properly.

Their use in engine lubricants increased in the 1970s due to the oil embargo. The lack of fuel led the automotive industry to improve fuel economy, thus reducing fuel usage. Continuous development has led to lower viscosity lubricants. Now, lubricants require robust friction modifiers to reduce wear and friction to offset the lower viscosity.

However, friction modifiers in these applications act differently based on shear conditions. This ensures equipment does not wear while also preventing too much slippage. This smooths the transition from a dynamic condition to static condition. For example, this is used in a gear change in a transmission.

Anti-Wear and Extreme Pressure (EP) Additives

As loads become heavier, engineers must adjust their lubricant to meet the tougher demands of heavier loads and higher temperatures. You should switch to a modifier that is classified as an anti-wear additive. A common and effective anti-wear agent is Zinc dialkyldithiophosphate (ZDDP). These additives react with metal surfaces once the environment reaches a high enough temperature.

As loads continue to increase, in addition to metal contact, the friction modifier must become more robust. In this instance, your lubricant must include extreme pressure (EP) additives. These additives are either temperature-dependent or not. Temperature-dependent EP additives activate as the metal surface temperature increases due to the extreme pressure. The reaction is driven by the heat produced from friction.

Final Thoughts

Lubricants with friction modifiers create more efficient operating environments. This leads to less wear, downtime, and carbon dioxide emissions. As friction modifier additives improve, lubricant manufacturers will aim to reduce to viscosity to reduce shear conditions. Conversely, this creates more components operating in thin boundary lubrication conditions. We will see continuous innovation of these additives to meet the performance and efficiency demands.

What are Lubricant Detergents?

Detergents Defined

Detergent additives perform two key functions. Like household detergents, the additives keep metal components clean and free of deposits. Additionally, detergents neutralize acids that form in the oil. This is key for systems where component cleanliness is essential. Originally developed for engine oils, detergents addressed carburetor deposits that could hamper performance. Detergent additives were also found effective in fuel injectors. The detergents reduced deposits that affected fuel spray patterns.

How do Detergents Work?

Detergent additives are basic in nature, thus serve as a neutralizer for acidic contaminants that may arise in your lubricant. In the past, these detergents were barium-based, however modern chemistry has allowed manufacturers to move to different formulations. Today, most additives use either calcium-based chemistry or magnesium-based chemistry. As an oil is subjected to oxidation, it will start to collect acids. As these acids build up, the oil’s Total Acid Number (TAN) will increase. The basic and alkaline detergent will neutralize the acids and reduce the TAN. However, as the detergent is used, the Total Base Number (TBN) will decrease to point where the oil will need to be replaced. Therefore, measuring TBN is crucial to engine performance and lubricant effectiveness.

In high-temperature applications, metal compounds leave an ash deposit when burned. This residue buildup requires many OEMs to require low-ash oils. Detergent additives are used to clean these deposits. However, dispersants are included as well to help clean the engine. Dispersants are used to keep engine soot particles suspended and prevent agglomeration (forming larger soot deposits). The dispersant and detergent work together to suspend contaminants and neutralize acids. Eventually, the additive capacity will exceed its limit and require users to change the oil and replenish the additives.

Detergent v. Non-Detergent Oil

How do you know if you need a lubricant with detergent additives? Usually, an OEM will specify whether the equipment needs a detergent oil or non-detergent oil. Applications that could face high levels of water and contamination are good fits for detergent oil. Some examples include: off-road equipment, marine equipment, trucks & fleets, and many more. The high levels of contamination need to be neutralized with dispersants in order to keep pumps and valves clean and running.

Sometimes, OEMs require oils to not have detergent additives. Some manufacturers will produce special Non-Detergent oil to meet these specifications since, most oils now have detergent additives for better performance. Non-detergent oils are used in bearings and chains in non-critical once-through systems. It is also recommended for gas-powered appliances such as lawnmowers and tractors. Some non-detergent oils are not recommended for automotive gasoline engines (detergent oils are recommended).

Detergent Oil Today

With the developments in detergent and dispersant technology, most oils now have some sort of detergent additive to help combat high TANs and prevent sludge build-up. Even though non-detergent oil is still marketed today, it is only required for a few specific applications and not recommended by many OEMs. When selecting your lubricant, detergency is important to consider because high detergency will protect your parts, keep your system clean, and maximize performance. If you are using non-detergent oil, consider making the switch to an oil that has detergent additives.

Twin Specialties offers both detergent and non-detergent oils to meet your specifications and OEM requirements. We also offer a variety of motor oils and heavy duty engine oils with high-quality detergent additives to meet your specifications and budget. Contact us today for more information.