Coatings, Cleaning Equipment, and HCFC 225

Barbara and Ed Kanegsberg, authors of the new "On the Surface" section in Metal Finishing magazine, give readers a "heads-up" about Federal EPA changes in allowable uses of solvents.

EPA Changes. If you were planning to stock up on HCFC 225 (hydrochlorofluorocarbon 225) to use in critical cleaning processes and surface preparation after the end of 2014, think again. You can’t! Reliable sources in the regulatory community indicate that the EPA has reinterpreted their position. You won’t be able to use virgin HCFC 225 in operations like dip tanks, ultrasonic tanks, hand-wipe, or degreasing. The reinterpretation impacts the entire United States, and it is related to Federal law, specifically to the Clean Air Act, and ultimately to the global Montreal Protocol. Because of the way the law is worded, you can continue to use virgin HCFC 225 in aerosols or in pre-packaged wipes. You can also continue to use recycled or reclaimed HCFC 225. So, if you have need for it, take steps now to lock down the quantity and quality of recycled chemical.1

If you haven’t already started, now is the time to work on an exit strategy--not from your business or from the U.S., but from HCFC 225. This means evaluating and testing water-based, solvent-based, and “non-chemical” cleaning processes.

Small changes? What if a new chemical is supposed to be almost like HCFC 225? The operative word is “almost.” Even supposedly small changes in the cleaning process can mean trouble. Plan ahead. Test the new cleaning agent with the cleaning equipment – you can’t assume they will work together. Make sure that the cleaning equipment works with more than one cleaning agent. You may be told that the cleaning equipment can be easily adapted to other solvents. “Easily adapted” is similar to “some assembly required.” Ask for details. Know the materials of construction of the tanks. Understand compatibility issues with the seals and transfer lines. Know the temperature range of operation of the cleaning equipment. Many proposed replacement vapor-degreasing solvents are relatively low-boiling, so investing in a well-contained system can prevent solvent dollars from wafting away.

In addition, your customers may need to know about the process change--and for many applications, the process may have to be revalidated or requalified. Start now, as such activities often take time.

Cleaning equipment, coating, and profits. Many of you use advanced, engineered coating techniques, such as cold spray and vapor deposition. These coatings can be highly adherent and perform well. However, exquisite care has to be taken in surface preparation. Small amounts of organic chemicals can compromise adhesion.2 Even traditional plating has gone high-tech, and with good reason. Your customers require better performance and lower prices. Regulatory restrictions have made applying the right coating more challenging.

Let’s suppose you are involved in heavy-duty fabrication such as metal forming, stamping, grinding or welding. Getting concerned about cleaning is good for business. Your customers have a choice in suppliers. Many platers, shops that specialize in engineered coatings, and final assemblers complain that their suppliers send inadequately cleaned parts or even parts that are dripping with oil. Help your customers make their job easier-- it’s good business.3

Process changes. Whether or not you use HCFC 225, many of you may want to purchase new cleaning process equipment. Whatever process you select, be prepared for capital investment, employee education, a learning curve, and some culture shock.

You may move from solvent-based to water-based cleaning. There are a number of good reasons; the mix of soils and process fluids may be more effectively removed by water-based cleaners. Many aqueous cleaning agents have a relatively favorable worker exposure profile. In some areas they may be easier to permit. With cleaning equipment, allow plenty of space and budget for a drier. The drying step is usually rate-limiting. Make sure the cleaning forces, both chemical and physical, adequately reach all surfaces and dislodge the soil. Spec the equipment to include enough rinsing to remove both residual soils and cleaning agents. Check the permitting requirements and water disposal requirements, and look into recycling options. Water is a scarce commodity; recycling can result in a more consistent process.

Or...you might move from water-based to solvent-based cleaning. There are a number of technical reasons. The solvency range for the newer metalworking fluids is such that organic cleaning chemicals may be preferable to water-based products. Formulations are changing nationally, partially to conform to California SCAQMD (South Coast Air Quality Management District) regulations that lower VOCs. In addition, certain Federal programs favor bio-based lubricants. In both instances, process fluids tend to have higher boiling temperature and the residue will be more adherent. More aggressive solvency may be needed. In addition, more complex product designs may require better wetting under tight spacing.

Even with solvent systems, agitation and/or ultrasonic cleaning may be required. The solvent has to be kept clean, free of particulates and metal fines. Equipment design and maintenance will be quite different from what employees are accustomed to. If you use a halogenated solvent, it has to be properly stabilized and checked periodically for acidity. Acid can damage the cleaning equipment and the parts being cleaned. Many organic solvents have employee exposure and/or environmental issues. Others are fairly expensive. All of these issues can be managed by good containment. However, this means very careful equipment selection.

Not all solvents have similar properties. If you are considering moving from either water or a degreasing solvent to a very high-boiling material, a multi-tank system allowing for solvent rinsing may be needed. Such systems may superficially resemble vapor degreasers, but the operation and potential “gotchas” can be very different.

Non-chemical cleaning can be appealing in that chemical storage, handling, and disposal may be eliminated. Examples include, grit blast, laser, carbon dioxide (snow, supercritical, or subcritical), steam, and plasma. If you move to non-chemical cleaning, please keep in mind that many such systems actually contain chemicals. For example, in plasma cleaning, chemicals are generated as part of the process. The chemicals may impact surface quality. With high levels of soil, pre-cleaning may be needed. For example, in thermal spray applications, aluminum oxide blast without prior pre-cleaning tends to simply move the organic soils around the surface; the coating won’t stick well.4,5

START NOW Start looking at cleaning equipment today, particularly if your cleaning agent is under regulatory duress. Start looking if you dream about changing your customer base. Avoid the temptation to make a last-minute purchase of used cleaning equipment. It may be fine, but too often manufacturers find that they have made a disastrous decision. 6 Even “gently used” cleaning equipment can have leaks or contain residue of other processes that interferes with what you are trying to do. Save time and money; buy high-quality equipment. If you must make a short-term decision, consider leasing the equipment. Review national, regional, and local environmental and worker-safety regulations. (Remember: regulations conflict, and, as in the case of HCFC 225, interpretations change.) Even if there’s no regulatory emergency with the chemical, optimize the cleaning process now--you will be in a great position to take the lead in maintaining your customer base and growing your business.

REFERENCES 1. B. Kanegsberg, “More Restrictions on HCFC 225 for Cleaning,” Clean Source, Sept. 2012; http://bfksolutions.com/index.php/newsletter/77-clean-source-newsletter/196-breaking-news-more-restrictions. 2. B. Kanegsberg, “Case Study: Cleaning in an Airless/Vacuum System Prior to Applying Engineered Coatings,” Handbook for Critical Cleaning: Applications, Processes, and Controls; CRC Press (2011), pg 208-213. 3. B. Kanegsberg and E. Kanegsberg, “On the Surface: Better Business through Strategic Cleaning,” Metal Finishing Magazine, May, 2012. 4. B. Kanegsberg, “Cost-Effective Cleaning for Quality Thermal Spray Coating,” International Thermal Spray Association, Orlando, FL, April 17, 2009. 5. B. Kanegsberg and E. Kanegsberg, “The Promise of Thermal Spray,” Galvanotechnik, September, 2010. 6. B. Kanegsberg, "Measure Twice, Clean Once," Clean Source, March 2012

ABOUT THE AUTHORS Barbara Kanegsberg and Ed Kanegsberg Ph.D., “the Cleaning Lady and the Rocket Scientist” of Los Angeles-based BFK, Solutions LLC (founded in 1994), are the industry leaders in critical/precision and industrial product cleaning. As independent consultants, they help manufacturers achieve rugged, trouble-free processes in areas such as metal forming and fabrication, aerospace, medical device manufacturing, electronics, optics, and consumer products. They are members of JS3, an interagency military/NASA working group involved with cleaning processes and Mil-spec development. They also write regularly for trade journals in the U.S. and overseas. Barbara and Ed are editors/contributors for the acclaimed, expanded two-volume Second Edition of the “Handbook for Critical Cleaning,” CRC Press, 2011. Contact: 310-349-3614 or send an e-mail to: info@bfksolutions.com.