1) How should I mix TRIM® products?
Mixing is crucial to maintaining stability in cutting and grinding fluids. Proper mixing instructions are available on all Master Chemical Data and Information Sheets. For optimum performance and maximum life, coolant concentrates should be mixed with chemically pure water produced by deionization or reverse osmosis. It is a general rule that concentrates should be added to the water last and mixed thoroughly. One way to remember the proper sequence of addition is to remember "O.I.L.", meaning "oil in last". Special mixing devices and proportioners like the UNIMIX™ and Master Mix™, which automate the mixing process and minimize the waste of concentrate, are available from Master Chemical. (Fluid Mixers)
2) At which concentration should I be running?
Master Chemical products are specifically designed to be used at a number of different concentrations. Each product and application will have an ideal concentration ratio for the metalworking fluid. The concentration will affect sump life, tool life, and surface finish. Master Chemical's Data and Information Sheets give examples of applications and their corresponding concentrations. Maintaining proper concentration is essential for efficient and trouble-free results from water-miscible cutting and grinding fluids. Master Chemical's Technical Service Laboratory estimates that well over 80% of the "trouble calls" received are directly or indirectly attributable to poor concentration control. Concentration control is difficult to achieve when the coolant is manually mixed in small batches and is virtually impossible to maintain when untrained operators mix coolant. The Systems Equipment Division carries a complete line of automatic proportioning equipment to maintain accurate coolant concentration control. (Fluid Mixers)
3) What is "makeup" concentration?
When water miscible coolants are used in machining and grinding operations the volume of fluid in the coolant sump decreases due to the physical loss of the fluid (fluid is carried off on chips and parts) and water evaporates because it absorbs heat generated in the machining or grinding operation. Proper operation requires that the fluid level is maintained at some minimum level and so "makeup fluid" must be added to replenish coolant carried out on chips and parts. Since the loss of water by evaporation causes the fluid in the sump to increase in concentration the "makeup fluid" will always be mixed at the same concentration less that of the recommended operating concentration. For example, if an emulsion coolant is to be run at 5% volume to water then the "makeup" concentration for that fluid will generally be 2.5-3.0%. Check your product data and information sheets for recommended working and "makeup" concentrations.
4) What is a refractometer factor?
The refractometer factor is used in determining concentration of a metalworking fluid. Each Master Chemical product has a refractive index factor for determining concentration. Consult the Data and Information Sheet for product specific refractive index factors. Multiply the refractive index (refractometer reading) by the refractometer factor and the result is the concentration of the working solution in percent. (The factor for most emulsion fluids is 1.0 so that the refractive index is the fluid concentration.)
5) Why does my coolant have an unpleasant smell?
An unpleasant coolant smell is most likely attributed to anaerobic bacteria. Bacteria produce waste products, which often contain sulfur and exude the "rotten-egg" smell. Bacteria are major contributors to coolant failure. They chemically alter coolants and destroy the lubricants and corrosion inhibitors in the process. They also pass off corrosive acids and salts into the coolant, which can lead to low pH and corrosion problems. The bacterial growth can be minimized by:
- Maintaining proper coolant concentration.
- Good housekeeping practices (cleanliness).
- Preventing or minimizing contamination.
- Good filtration of the coolant and continuously removing chips. Thorough, periodic sump clean-outs.
Oftentimes, "cover-ups" which are perfumes, can be used to mask odors but they are not a cure and their use can lead to more serious fluid problems later.
6) Why are coolants different colors?
Most coolants exhibit colors and odors that result from the chemicals from which they are blended. But sometimes metal cutting fluid manufacturers use dyes and colorants to give them an aesthetic appeal. They are also helpful in identification of products for companies which use a number of different products. Machine operators sometimes use color intensity as an indication of coolant concentration. Color intensity is not a good indicator of concentration as tramp oil can absorb the dyes used, and some work materials (such as cast iron) can "mask" the dye. Even with dyed coolants it is necessary to check fluid concentration properly periodically.
7) What is the residue in the sump or machine tool?
Residue is the material left behind on the machine and workpieces after the water evaporates from the coolant solution. Residues should never interfere with the smooth and proper machine tool function but more importantly the residue should enhance the machine's operation. Residues may be classified as:
For optimum machine tool functioning, oily, non-gummy residues are preferable. If a residue is hard, gummy or crystalline, it can cause a machine's moving parts to "stick" or "freeze" and may cause a machine malfunction. A moderate crystalline film may be tolerated on certain types of surface grinders but such a residue could cause a major problem on a 5-axis machining center. In other words, the type of machine must be considered when selecting a fluid because the type of residue may dramatically affect the machine function.
8) Why am I experiencing skin irritation?
Occupational Dermatitis is a term used to describe any abnormality of the skin induced or aggravated by the work environment. Dermatitis is somewhat more specific in that it refers only to inflammation or irritation of the skin.
There are four possible mechanisms by which dermatitis may be introduced:
- Mechanical injury caused by friction, pressure, or trauma, including abrasion.
- Chemical attack from the precipitation of protein by acid.
- Physical agents including excessive heat or cold, radiation, or electricity.
- Biological agents like insect bites or plants, such as poison ivy, poison oak, and poison sumac.
The following is a list of the more common causes of dermatitis in the metalworking environment:
- Alkalinity: Prolonged contact with highly alkaline materials.
- Acidity: Acids from any contaminating source will eventually lower pH and levels below pH 7 will irritate normal skin.
- Solvents: Solvents remove the natural protective oils from the skin and leave skin more open to chemical attack.
- Metals: Metals like zinc, cadmium, chrome, and nickel can cause an allergic reaction or even severe skin irritation.
- Straight cutting oils: Many straight cutting oils contain active sulfur which will release acid when in contact with water. Coolants contain alkaline materials and can contain detergents or emulsifiers. At high concentrations these can irritate and dry the skin.
- Concentration: High concentrations should be avoided and not exceed the maximum recommended concentration.
- Filthy coolant: Suspended metal fines and abrasive grain can wear away the skin and do serious injury. Filter coolant to remove these abrasive particles or change the coolant more frequently.
9) Is coolant a hazardous waste and how do I dispose of it?
Used coolant should not be introduced directly into sanitary or storm sewers because of contamination from various oils and metal particles. Since all used coolants contain petroleum oils, either by virtue of their composition or because of tramp oil contamination, they must not be emptied into sanitary sewers without treatment.
Most smaller metalworking plants pay to have used coolant hauled away for proper waste treatment and ultimate disposal. It is important to note that legally, title to waste does not pass to the hauler but remains with the generating facility. For this reason it is important that only reputable, licensed firms be engaged for disposal processes only.
Other options for disposal include: evaporation, or incineration and chemical treatment to separate oil and fluid concentrates from the water so that the water meets local sewer codes. Check with your local waste ordinances prior to disposal.
10) Will mist from the cutting fluid hurt me?
Master Chemical is the first American metalworking fluid manufacturer to begin testing its fluids for their affects on human health. In 1953, we began testing our fluids for dermal safety on human volunteers and today we also have them tested for eye and skin irritation as well as for acute inhalation and oral toxicity. Since Master Chemical is totally committed to producing only safe products, all of our formulas must be non-toxic as well as be non-irritating at their maximum recommended concentration. Additionally, Master Chemical has a firm policy of not using any ingredients with known or even suspected adverse effects on human health.
Never-the-less, once in use metalworking fluids become contaminated with lubricating and hydraulic fluids from machine tools, metal fines, abrasive grain and bond, and even some metal ions from the processed parts will eventually dissolve in the fluid. Because of the variety of materials which can contaminate coolant solutions, it is impossible to evaluate the safety of these used fluids in the laboratory.
There are no scientifically definitive studies that indicate coolant mists generally present a significant hazard to machine operators. The exception to this is that coolant used to grind carbide cutting tools under production conditions can sometimes dissolve appreciable amounts of the cobalt binder, and mists containing high levels of cobalt can produce what is called "hard metal disease," which can seriously impair lung function. For this reason, mists from coolants used to grind carbide should be avoided and the fluid tested regularly to monitor cobalt levels.
Although coolant mists generally have not been shown to be hazardous, when dealing with a scientific unknown it is always best to err on the side of caution. For this reason Master Chemical recommends avoiding inhaling coolant mists as much as possible. We further recommend that machine enclosures be kept closed during the machining or grinding operations and that enclosures, gaskets, and seals be maintained for proper functioning to minimize the escape of mists into the shop atmosphere. We further recommend that plants take the necessary steps to ensure that there is adequate fresh air make up and ventilation.
The Occupational Health and Safety Administration currently has in place a regulation requiring plants to keep oil mists at or below 5 mg of oil per cubic meter. Oil mists are primarily a concern with machines using straight or neat oils. However, when coolants become heavily contaminated with tramp, lubricating and hydraulic oils these oils can vaporize when splashed onto hot tooling or when atomized in grinding operations. For this reason (and others) Master Chemical recommends that tramp oil leakage be minimized however possible and that machines with hydraulic leaks, which cannot be fixed, be fitted with skimmers or coalescers to remove the contaminating oils. Additionally, since some oils will tend to emulsify in most coolants, we recommend that coolants be recycled periodically through a high-speed, disc-bowl centrifuge to remove emulsified tramp oil. If a plant does not have recycling capabilities then coolants should be disposed of properly when tramp oil levels become significant.
11) May I have an MSDS (Material and Safety Data Sheet) sheet?
MSDS sheets are made available by all product manufacturers and must contain any hazardous ingredient information along with threshold limits on ingredients. Contact your Master Chemical distributor or us directly for Material and Safety Data Sheets for TRIM® products that you are using or considering for use. firstname.lastname@example.org
12) Why are my parts rusting in the process, or in storage? What can I do about corrosion?
Possible causes of rusting include:
- Acidity will affect both ferrous and nonferrous metals; check the pH of the coolant and the bacterial contamination level.
- Alkalinity can affect non-ferrous metals; check the pH of the coolant and if high, (see question 10), check for contamination of the coolant by highly alkaline materials such as floor cleaners or alkaline cleaners.
- Dissolved salts from the plant water supply or from heat-treating and plating processes can be a contributor to corrosion problems.
- Stacking different kinds of metals in contact with one another can cause galvanic corrosion (example: steel and aluminum).
- Unless properly processed, wood, paper and cardboard are acidic and contain corrosive salts and should not be used as separators in tote boxes. Use an acid free plastic mesh. Tote boxes should allow parts to dry rapidly.
- Parts should not be blown off with an air hose. Flush chips off with a coolant hose or dip the parts in clean coolant to remove chips and/or swarf.
- Do not use active sulfurized/chlorinated cutting oils in conjunction with water-soluble coolants.
- Poor coolant concentration control.
- Germicides and other coolant additives may be corrosive; add them only at the proper concentration.
- The improper application of rust inhibitors; coolants are designed to provide short term, "in process" corrosion inhibition. Long term storage (two weeks plus) will usually necessitate the application of other corrosion inhibitors.
13) If I sent a coolant sample to Master Chemical where can I get my lab report and what does it mean?
Lab reports are generated by Master Chemical's Technical Services Laboratory and can be obtained through your local TRIM® Distributor. Lab reports will list general results like pH, conductivity, percent of tramp oil, bacterial levels, and concentration by refractive index. Your Distributor's coolant specialist or your Master Chemical District Manager will help you interpret the results.
14) Why do I have foam?
Most coolants will foam to some degree because the lubricants and wetting agents (soap like materials) present will form bubbles when they are agitate in the presence of a gas (air). In certain operations, controlled foam is necessary for functional requirements, but excessive foam can be a serious problem. Generally, large bubbles are unstable and will break readily. Tight, "shaving cream" bubbles are stable and will not break and present a problem by spilling out of the sump on the shop floor causing housekeeping problems. More importantly stable foams do not cool or lubricate and can cause tools to break or ruin surface finish. Every foam problem is an individual circumstance and has to be considered on its own merits. Therefore, if foaming occurs check for:
- Air leaks in valve stems from loose packing.
- Shaft packing in pumps.
- Pipe unions and connectors.
- Pump by-pass valves opening and "jetting" high-pressure coolant back into the coolant sump.
- Excessive cascading or "dropping" of the coolant to the tank surface.
- Pump cavitation.
If these problems cannot be handled by mechanical adjustments, then contact your Master Chemical District Manager or your TRIM® Distributor for recommended TRIM® TC Antifoam that will help to control the foaming problem. They may recommend a lower foaming coolant that would be better suited to your applications.
15) What is antifoam? How do I use it? How much do I add?
Antifoam is a product designed to knock down foam in coolant sumps by rupturing the foam bubble cells. It is most generally applied directly into the system immediately upstream of the foam or directly onto the foam.
Add antifoams at the lowest recommended dosage. Too much is not always better. Almost invariably antifoams will be filtered out of the coolant or they will be carried out on chips and parts. Plan on adding them periodically.
16) Which product do you have which is like the one I am using now?
Due to the many different types of operations and the variety of material types, product recommendations need to be made carefully. It is entirely possible that the product you are currently using is not ideal for your operations. If you can supply information on your work materials, your machines, your tool materials and the operations you are performing, your TRIM Distributor will be pleased to recommend a product which will be matched to your objectives. Your local Master Chemical District Manager can usually recommend a product based on the information supplied by you. email@example.com
17) Why is tramp oil a problem in my system?
Tramp oils (lubricating, cutting and hydraulic oils and greases) have serious, adverse effects on water miscible cutting and grinding fluids. Tramp oils cause a loss of wetting and thereby will degrade both the workpiece surface finish and tool life. They also reduce the cooling effect of the fluid that also impacts tool life. Tramp oils will impede filtration and contribute to unfavorable residues on machine tools and workpieces. Environmentally, tramp oils contribute to smoke and oil mist and stimulate the growth of bacteria.
These adverse effects are proportional to the amount of tramp oil present and, therefore, are most pronounced on those machines which leak the most oil. As bad as these effects are on "individual sump" machines, they are even worse in central systems where continuous recirculation through powerful pumps keeps the oil emulsified.
Master Chemical manufactures oil skimmers, and coalescers and sells and services high-speed, disc-bowl centrifuges to keep tramp oil levels under control. They are available through your local Master Chemical Distributor. (High-speed Centrifuges)
18) Why does the machine sump smell badly after a few days shut-down?
When a machine is shut down for a few days some of the tramp oil in the fluid separates and rises to the top of the sump sealing off the fluid from the air. Anaerobic bacteria grow and reproduce without the need of oxygen. As a matter of fact oxygen actually inhibits their growth. These bacteria in the stagnant fluid now begin to grow and release hydrogen sulfide (H2S) gas that dissolves in the coolant. When the coolant pumps are turned on at the end of the shut down the dissolved H2S is released to the atmosphere. H2S has the characteristic odor of rotten eggs and the human nose can detect it at the 1-2 parts per billion level. Talk to your Master Chemical District Manager or your TRIM® distributor about ways of controlling this persistent problem.
19) How much of TRIM® TC ______ do I use?
TRIM® TC additives are designed for different applications. Each product has a different addition rate. Consult the product's Data and Information Sheet.
20) Can I mix one type of fluid with another?
Water miscible fluids are all different by design. While most products are compatible it is advisable to consult Master Chemical Corporation for specific instructions on mixing different fluids together. firstname.lastname@example.org