A senior chemist at KTA-Tator, Inc., Chrissy Stewart is heavily involved in failure analysis using various analytical procedures to determine the cause of premature coating failures. She also creates customized coating material test programs (either compositional or exposure) for individual clients.
During her nine-year tenure with KTA, Stewart has acquired SSPC’s Protective Coating Specialist (PCS) certification, has become a voting member of ASTM and is a past president of the Pittsburgh Society for Coatings Technology (PSCT). She has also had multiple articles published in JPCL.
Developing a Connection with a Piece of Equipment
Attracted to the idea of solving scientific mysteries through analysis, Stewart had originally intended to major in (chemistry-heavy) forensic science, but graduated with a degree in chemistry instead.
“I graduated college wanting to work in a laboratory setting, but with no clearly defined path of what exactly I wanted to work with. Chemistry has a very broad range of applicable industries but there are very few programs at the collegiate level that are dedicated strictly to coatings.”
She left college with a penchant for, and a thorough familiarity with, infrared spectroscopy. “Almost every lab in organic chemistry ended with running an IR and interpreting the results.” An interview with KTA included a lab tour and when Stewart spotted the infrared spectrometer, she felt right at home.
Her mystery-solving pursuits have taken her down real-world paths. Stewart has testified in court and been deposed several times as an expert witness. When her friends and relations make the joke, “This is Chrissy; she watches paint dry,” Stewart responds with, “Yes, in accordance with ASTM D1640.”
“Knowing that one of the responsibilities in my career includes serving as an expert witness kind of opened their eyes to the fact that there is so much more to what I do, and so much more to my industry, than watching paint dry,” says Stewart.
She’s even on duty when she’s off duty. In an episode of the detective show Psych, the lab had taken samples from under a murder victim’s fingernails, run an IR (much to her delight), and detected talc and titanium dioxide. Stewart was impressed with the writers’ attention to accuracy when the show’s characters announced that the chemicals present were all pigments commonly found in paint. Turns out the victim scratched the wall as he was being murdered. Mystery solved.
Stewart had a test-method client interested in marketing commercially available additives that the customer would add directly to paint. The intent would be to stock their additives in the paint section of home improvement stores. The client was interested in knowing if their additives had any adverse effect on the paint materials themselves. “There is no shortage of testing that we could do to determine various properties of the coating materials, but we decided to start with a narrow scope to see if some of the most important properties may have been affected. For example, we were certainly interested in adhesion. If the paint doesn’t stick, it really doesn’t matter if all of the other properties are fantastic.
“We purchased several interior and exterior products by different manufacturers from local retailers. We performed the selected testing on the control materials (without the additives) and on the materials with the various additives and compared the results to see if the additives had any negative effect on the control materials.”
In another testing program, Stewart had a client who was experiencing trouble with adhesion of a custom color batch of a particular product. The client had used the same product on numerous occasions, but this was the first time he had to order a custom color. “We designed a test program that involved checking for chemical consistency between the failing and non-failing batches of material. This testing encompassed determining whether or not the components of the material were mixed at the right ratio, if the material had been exposed to proper baking conditions (oven temperature and duration), looking for general consistencies or inconsistencies between the failing and non-failing products, and also looking for evidence of organic contamination that may have had an effect on adhesion. Additionally, we performed a recoat study employing different variables which included time between coats and surface preparation.”
Often times, her company will get requests for testing to a specific standard. For example, the American Water Works Association standard, AWWA C222, contains approximately eight to 10 different laboratory test methods for polyurethane coatings on interior and exterior surfaces of steel water pipe.
“We are very familiar with the AWWA coating standards and are equipped to perform the testing associated with them. But sometimes we will get a call from someone asking if we test to ‘Standard XYZ.’ In these cases, we take an in-depth look at the standard and determine if our laboratory is equipped to perform the testing. Sometimes we are, sometimes we are not. We recently expanded laboratory services and acquired a building specifically engineered for autoclave services, due to several specifications, such as Saudi Aramco Materials System Specification (SAMSS 067) which requires autoclave chemical-resistance testing.
Stewart and her supervisor Cynthia O’Malley presented an interactive session at the SSPC 2015 conference. “Coating Failure Investigations in Action” provided a set of scenarios in which the participants follow the consultant and laboratory analyst on their journey and decide what the investigators should do at crucial points in the investigative process. The case studies mimic real-world information that comes in a variety of forms and must be thoroughly evaluated when making important decisions regarding the actions necessary throughout the progression of the investigation. Says O’Malley, “Chrissy has made very specific contributions to the industry, such as engineering the first-of-its-kind interactive workshop on coating failure investigation.”
Contributions Above and Beyond
Nominated by O’Malley for this recognition, she maintains that Stewart “is a firm believer in leading by example. She has embraced the opportunity to become further entrenched with the growth of both KTA laboratory services and the company as a whole by enthusiastically participating on the KTA strategic planning committee.”
Stewart’s testing methodology has been adopted by multiple organizations and she has assisted with the development of techniques for evaluation and qualification of interior and exterior pipeline coatings.
Says O’Malley, “Chrissy has completed a chapter on coating composition for the American Society for Metals (ASM) scheduled for a publication in September 2015 and has identified and defined research initiatives on complex issues challenging the industry, such as identifying test methodology variables to improve the accuracy of differential scanning calorimetry applications for determining the percent of metallic zinc of zinc powder and applied coating films.”
Advice for Those Following Her Path
Earlier this year, Stewart had the honor of being selected as a local judge for the chemistry category of the Intel International Science and Engineering Fair (Intel ISEF). Here more than 1,700 high school students from over 70 countries, regions and territories compete for more than $5 million in prizes. However, Stewart did not see much of a connection to the coatings field at the science fair. “I would say that perhaps the younger generations aren’t aware of the coatings field as a potential career path. There was a lot of focus on the medical field at the fair, but medicine is something we are all familiar with very early in our lives. And many students partnered with local universities, who also have a tendency to veer toward research in the medical field.
“In our industry we do a great job of sharing new information, technology and current dilemmas with those already involved in the industry, but there is little outreach that I have seen to those outside, particularly to young students.”
So what is Stewart’s message to those coming up behind her? “I hope you like to read. There’s really no shortage of new information out there and as soon as you think you know it, technology is constantly changing. If you think this field is a good fit for you – if it sounds like it, then it really is – it’s a fantastic path.”
When she’s not testing adhesion she’s hoping her cookies don’t stick, as Stewart is an avid baker. She’s been invited to quite a few weddings lately and has been “running her oven ragged,” baking cookies almost continuously for her contributions to the “cookie tables.” She also belongs to several book clubs including one currently dissecting the Harry Potter series with college friends, some of whom were English majors. “It’s really interesting discussing the books with people whose course of study was in interpreting literature.”