PARTS CLEANING NEWS

The Evolution of Cleaning Technology in Heat Treating: Time To Rethink the Approach

This instructive piece was first released in Heat Treat Today’s April 2025 Induction Heating & Melting print edition.


In heat treating, clean parts are essential for repeatable, high-quality results. Yet cleaning is often seen as a necessary evil rather than a strategic process. That mindset must change. 

For decades, gas carburizing with oil quenching has dominated the industry despite challenges, such as contamination, environmental concerns, and part distortion. These issues have driven growth in alternative processes, such as vacuum carburizing with gas quenching and nitriding, which eliminate post-quench oil contamination. However, not all metallurgical requirements can be met with these newer processes, and gas carburizing with oil quenching remains necessary for many part sizes, geometries, and material types. Furthermore, some alternative processes require more advanced pre-cleaning technology, adding complexity. 

I briefly left heat treating in 1998 — I call it my sabbatical from heat treating — to work in advanced industrial cleaning and automation. When I returned about five years later, I was struck by how far behind the industry was in cleaning technology. While other manufacturing sectors had embraced modern solvent and hybrid cleaning systems, heat treating continued to rely on outdated aqueous washers that struggle to clean oil-contaminated parts effectively. It goes back to the old axiom: oil and water don’t mix. Spraying harder only emulsifies the oil further, making separation and disposal even more difficult, increasing costs, and creating sustainability concerns. 

Paths Forward 

  1. Process shift — Where practical, companies have transitioned from oil quenching to vacuum carburizing with gas quenching, nitriding, and other alternative processes that reduce contamination issues. Of course, such changes are not driven solely by cleanliness — metallurgical requirements and process economics are complex topics. Gas carburizing with salt quenching is an often overlooked alternative, which offers superior heat transfer over gas quenching, reduces distortion, and is environmentally sustainable. Unlike oil quenching, cleaning aft er salt quenching is far simpler, as hot-water washers reclaim over 99% of the salt in a closed-loop system. The old negative mindset about salt, which questions the safety and toxicity of high temperature salt, has restrained process growth in this area. New equipment designs could create interesting, alternative paths with multiple benefits. 
  2. Mindset shift — If oil quenching remains necessary, cleaning processes must improve. Conventional aqueous washers are inefficient, and while modern cleaning systems are effective, they are costly. However, when considering part quality, sustainability, efficiency, and long-term cost savings, these systems provide a strong ROI and should not be dismissed. 
  3. Technology shift — Sustainability in cleaning cannot be ignored. Water-based systems with distillation attempt to recycle but have high energy costs, making solvent-based systems with integrated distillation more practical for higher efficiency and lower hazardous waste output.  
Rugged environments (left) require cleaning systems that modern washers are not often built for. Many new washers are more suited to clean controlled environments like vacuum heat treating (right). (Images from “All About IQ Furnace Systems,” 16)

Challenges with Modern Washer Designs — Thoughts for Manufacturers  

One major barrier to adopting advanced cleaning systems is cost, driven by their design. Many new washers are built for clean, controlled environments like vacuum heat treating but are poorly suited for traditional heat treat shops using oil quenching. Th ese shops have different requirements — floor space constraints, varied load configurations, and harsher conditions — meaning rugged, adaptable, and cost-effective solutions are needed. Function must take priority over aesthetics. 

Washer manufacturers should rethink their designs to better fit conventional operations by focusing on durability, modularity, and cost-conscious engineering. Doing so could lower costs while improving adoption rates and accelerating industry-wide improvements in part cleanliness, quality, and sustainability. 

Conclusion 

Heat treating is changing, and cleaning technology must evolve with it. Whether by adopting better process alternatives, improving cleaning methods, or rethinking equipment design, companies that embrace innovation will reduce waste, improve efficiency, and ensure long-term success with a stronger commitment to sustainability and environmental responsibility. 

The industry is evolving. It’s time to evolve with it. 

References

About The Author:

William (Bill) Disler
President
WDD Consulting LLC

William (Bill) Disler entered the heat treat industry as a young engineer, quickly establishing himself as a hands-on expert and eventually leading an international heat treat supplier company as CEO/president. He now serves the industry as a strategic advisor and partner to the C-Suite, as an engaged board member, through his consultancy, WDD Consulting, and in roles where he can make a positive impact. 

For more information: Contact Bill Disler at wdisler@wddconsulting.com 



The Evolution of Cleaning Technology in Heat Treating: Time To Rethink the Approach Read More »

New Furnace Line for Railroad Component Manufacturer

A supplier to the railway industry has ordered a technological line consisting of two vacuum furnaces, three tempering furnaces, and two washers. The line will be utilized for hardening processes of steel parts used in railway rolling stock.

The SECO/WARWICK line for voestalpine Fastening Systems consists of an electric chamber furnace, a washer, a cooling station, and an endothermic atmosphere generator. The hardening process will be carried out in a controlled atmosphere with temperatures up to 1742°F.

Additionally, the technological line includes an electric chamber furnace designed for the heat treatment of steel parts in a protective nitrogen atmosphere at temperatures up to 1292°F, along with a washer, cooling station and endothermic generator. The line will include a loader operating in automatic mode, a set of roller tables and a closed loop water system. The number of the supplied technological line units is selected to ensure the quality of manufactured components.

Mariusz Raszewski, Deputy Director of the Aluminum Process and CAB Furnaces Team, SECO/WARWICK (Source: SECO/WARWICK)

Mariusz Raszewski, deputy director of the Aluminum Process and CAB Furnaces Team at SECO/WARWICK said, “The line is configured in such a way that if the volume of the company products decreases, the customer can also offer commercial processing due to the wide technological spectrum of this main furnace unit.”

The whole solution will be supervised by a master system, which is used for the continuous monitoring of the heat treatment equipment operation and provides advanced data analysis for the production processes.

Mariusz Fogtman, COO, voestalpine Fastening Systems (Source: voestalpine Fastening Systems)

“The universal furnace solution will allow [us] to process details in various configurations,” Mariusz Fogtman, COO of voestalpine Fastening Systems commented. “Apart from technological parameters, it is important for us to limit the processed details’ deformations, which is possible in the ordered solution. SECO/WARWICK presented a partnership and flexible approach to the challenge of this order”

This press release is available in its original form here.

New Furnace Line for Railroad Component Manufacturer Read More »

Upton Industries Acquired by Kolene Corporation

HTD Size-PR LogoHeat treat solution manufacturer in Roseville, MI has been acquired by Kolene Corporation, a global leader of custom-designed and engineered molten salt bath equipment and specialty chemical formulations.

Upton Industries, Inc.

"We are proud to carry on Upton's strong brand and legacy as a part of Kolene Corporation as we move forward," commented Roger L. Shoemaker, chairman & CEO of the company.

Founded in 1937, Upton Industries, Inc. design and manufacture thermal processing systems in the metal heat treating industry. They apply their Engineered Thermal Solutions methodology to heat treat equipment including box type, car bottom, lift-off and specialty furnaces that utilize either electric heating or gas-fired systems.

Kolene will maintain both its Detroit headquarters location and the Upton Roseville location, which will be home to all Kolene’s manufacturing and fabrication. Bringing the two companies together will give the new company 50,000 sq. ft. of manufacturing, fabrication, and commercial processing capabilities.

W. Scott Schilling
President
Kolene Corporation

"After thoroughly evaluating Upton’s capabilities," said W. Scott Schilling, president of Kolene, "it was apparent that there are tremendous synergies between the two companies. Capitalizing on these synergies will allow [the company] to expand into applications and revenue segments where we have not historically been. [We] will also have the ability to become more vertically integrated due to Upton’s manufacturing and fabrications capabilities, which will allow us to strengthen our overall margins."

In its 82nd year, Detroit-based Kolene Corporation provides custom-designed and engineered equipment, specialized chemical formulations, and processes for cleaning and conditioning metal surfaces. Currently, their products are used worldwide for casting cleaning, alloy descaling, coatings removal, engine rebuild and other demanding automotive, industrial, and military applications.

Upton Industries Acquired by Kolene Corporation Read More »

Mercury Marine Launches Heat Treat Upgrades

HTD Size-PR LogoMercury Marine of Fond du Lac, Wisconsin, recently launched a plan to upgrade its heat-treating capabilities with a move to the low-pressure carburization and high-pressure gas quench system. The new plan incorporates completely automated vacuum heat treating systems.

In the partnership with ECM Technologies, the Nano vacuum heat treating system (pictured above) incorporates 20 bar nitrogen gas quenching along with low pressure carburizing (aka vacuum carburizing). The Nano will operate several different carburizing, hardening, and spheroidizing processes simultaneously.

This change marks a departure from Mercury’s traditional atmospheric carburization and oil quench system while benefiting from advantages that come with vacuum processing:

  • Applies vacuum heat treating in lieu of traditional atmosphere (elimination of intergranular oxidation & highly repeatable process with consistent results)
  • Employs preventive maintenance planning, remote system status access, and facility information systems integration
  • Relocates heat treat from a secondary location to the clean, controlled environment of the machining centers
  • Converts to small batch processing principles to maximize process efficiency
  • State-of-the-art growth with ECM’s advanced system automation and robot capability with load building and breakdown
  • Controls downstream operations by matching incoming dunnage with exiting workpieces
  • Takes advantage of vapor and vacuum-based pre-cleaning technology to remove multiple machining lubricants
  • Incorporates cryogenic and tempering processes within the automated system

The system uses all CFC workload fixtures and ECM’s advanced automation fixture tracking to maintain a precise cycle count to know fixture life. For Mercury, this significantly reduces energy consumption and process cost per piece. Additionally, the vacuum process takes their heat treatment to a near-zero emissions for drivetrain components processed within the system.

Mercury Marine Launches Heat Treat Upgrades Read More »

Global Leader in Industrial Cleaning Products Adds Heat Treating Salts to Product Line

HTD Size-PR LogoGlobal leader in industrial cleaning products based in North America acquires a Canadian chemical division, expanding its offerings to include molten salt for the heat treat market.

Kolene Corporation has acquired the chemical division of Park Thermal International Corporation. The president of Park Thermal, Jay Mistry, will work with Kolene going forward to assure the transition of all Park Thermal standard and proprietary heat treat chemical blends, as well as providing customer support.

Peter Shoemaker
Vice President of Purchasing
Kolene
Source: PRNewsWire

"We are very excited to broaden our molten salt offerings into the heat treat market and utilize Jay’s extensive chemical knowledge and excellent technical customer support to do so," says Peter Shoemaker, VP of purchasing at Kolene. "It’s great to have Jay as a partner with Kolene as we relaunch the industry trusted Iso-Therm product line."

"We were challenged with the Covid downturn in our business," stated Jay Mistry, "and we were looking for a strong partner to continue supporting our established customer base. I am glad to have found the Kolene team, a trusted and competent North American partner who has the technical and commercial bandwidth to carry our heat treat salt business into the next phase."

Kolene Corporation has been a trusted brand for both ferrous and non-ferrous metal cleaning products for 82 years and is also known for their ferritic nitrocarburizing (FNC) salts.

Park Thermal International Corporation of Georgetown, Ontario, Canada, was founded in 1938. Jay Mistry started as chemist at Park Thermal in 1989 and bought out the company from Brian Reid in 2017. Since then, Park Thermal has developed chemical blends for special client demands.

Global Leader in Industrial Cleaning Products Adds Heat Treating Salts to Product Line Read More »

Cleaning Workpieces: Vacuum Vapor Degreasing

Source: VAC AERO International

 

In order to maintain the cleanliness of workpieces and baskets or fixtures in the vacuum heat treating or brazing process, it is helpful to establish a pre-treating cleaning practice. Vapor degreasing has emerged as a cleaning process with the acting principle that the solvents will dissolve the contaminants on the workpiece and remove them by dripping off the part. In this week’s Technical Tuesday article, a Best of the Web feature, we bring you an article from VAC AERO International addressing the development of the process, the steps involved in vapor degreasing, and comparisons with other cleaning methods.

Cleaning in a solvent offers a level of simplicity and forgiveness not seen in aqueous methods. At one time, solvent cleaning was considered mandatory for successful vacuum processing but environmental concerns (VOC and other emissions) and improvements to aqueous systems including drying technology has seen the industry shift to aqueous cleaning as the norm. Today, however, with the advent of vacuum technology, vacuum vapor degreasing has emerged as a viable alternative to aqueous processing.”

A preview:

Vacuum vapor degreaser schematic with operational sequence steps. (“Removal of Entrained Moisture from Powdered Metal Parts Using High-Temperature Solvent and Vacuum” PM2TEC 2003, via VAC AERO International)

Main image photo credit/caption: Vacuum Processing Systems LLC (via VAC AERO International) / Typical vacuum vapor degreaser 

Read more: “Vacuum Vapor Degreasing”

Cleaning Workpieces: Vacuum Vapor Degreasing Read More »

Furnace Manufacturer Unveils Cleaning Process for Heat Exchangers

A leading vacuum furnace manufacturer recently announced the development of an improved process to clean heat exchanger fins that become clogged with debris and dirt. A clogged heat exchanger greatly impedes quench gas flow, resulting in reduced work cooling rates.

Solar Atmospheres of Souderton, Pennsylvania, states that its special process involves a 12-hour soak, water jets recirculating forced water, pressure washing, and nitrogen gas drying to result in an “as new” condition.

 

Furnace Manufacturer Unveils Cleaning Process for Heat Exchangers Read More »

Advanced Technology for Precision Cleaning Applications Launched

 

A metalworking fluids and services company based in Valley Forge, Pennsylvania, recently developed an advanced cleaner designed to replace highly volatile solvents in precision cleaning applications where flammability, health, safety and environmental factors are concerns.

Tony Pavesich, Houghton Surface Finishing Industry Leader

Houghton International introduced Houghto-Rinse RTD™, a water-based, non-flammable, ready-to-use cleaner that delivers process performance and surface appearance in a wide range of surface finishing applications, particularly for its industry markets of automotive, aerospace, metals, mining, machinery, offshore and beverage industries. The product is designed to remove surface residues such as spray paint, marker pen, ink, glue, grease, and production soil prior to final inspection, assembly or packaging and is safe for use on all surfaces including aluminum, steel, magnesium, plastics, painted surfaces, and fiberglass.

“Extensive field testing has demonstrated that Houghto-Rinse RTD delivers outstanding cleaning performance on a broad range of applications,” said Tony Pavesich, Houghton Surface Finishing Industry Leader. “It dries quickly, leaves no residue, and is ready-to-use, so it improves product quality and process efficiency.” The product is also economical, low-odor, and contains rust prevention properties, which may be important when used to clean steel components in critical applications.

Advanced Technology for Precision Cleaning Applications Launched Read More »