Lessons learned

TLT Sounding Board June 2022


Executive Summary
The lessons we learn through struggles, mistakes and failures can shine a positive light on experiences that may seem to be only negative. In the tribology and lubrication fields, this can mean learning something new about lubricants or additives, figuring out how to serve a customer’s unique needs or even just reinforcing best practices. In reflections on past failures, a majority of readers recognize the opportunity for growth that was presented and agree that it is worthwhile to share these experiences.

Q.1 Describe one of your largest lubrication, tribology or research failures.  Q.2 What were the key lessons learned and/or changes that resulted from the experience?
Changing a hydraulic system that once had glycol in it and refilling the system with mineral oil. The remaining glycol had adhered to the bearing surfaces (including bronze and Teflon) and during operation had wore down the bearing surfaces prematurely. Complete system disassembly was required to fully clean all internal surfaces of components when using incompatible fluids. 
Developed a new additive but could not apply to the market. New molecule or new chemistry needs to be registered first before going into market, and registration fee is very costly.
Task: designing a test apparatus to replicate a field issue. The project team worked for more than a year trying to refine the laboratory test method and equipment. We ended up not being able to successfully replicate the field issue. The fundamental interactions that caused the field issue remained unknown; only fluid sample analysis and hardware examinations after failure were available. The hypothesis that drove the research either was unable to scale down to a laboratory environment, or was incomplete. Tribological failures can have many subtle interactions that add up over time. Pointing to the one or two large obvious answers are often not enough to determine a root cause and develop a comprehensive solution. 
We were doing a project and ran up against a thermodynamic limitation. Despite that, we kept going because our competitor was continuing the project. We later found out when they acquired us, they had seen the same issue with thermodynamics but continued because we were.  Trust your own judgement, and don’t let outside influences change the decision when the data are clear. 
Applying a laser surface texturing technique that was not robust enough resulted in inconclusive results. Failure to select an adequate laser source with shorter pulse durations would have improved our chances to reach our desired outcome (friction reduction). Decoupling tool selection from industrial requirements at an early stage. 
Most of our failures have been related to unclear scale-up instructions. The lab knew what they wanted but didn’t effectively communicate with the factory. Always have a person from the development team directly and personally involved in a scale-up. The lab and plant do not always speak the same language, so it is dangerous to rely on written or verbal instructions to convey all of the details correctly.
The improper initial determination of the cause of broken tipper rear axle bearing. The most problematic was the determination of all causes of such a break. This engaged metallographic, finite element method analysis, grease analysis and environmental interview with the participants of the accident, so it was a very complex problem, and the most important thing was the occurrence of hidden defects in the material of the components.
Tried a full synthetic stamping fluid in an operation that needed a full solution (oil-based) stamping fluid. Some tough operations need more lubricity than cooling the dies and tools.
Changes in the additives we use over time. We need to better document the original performance and recheck it once in a while to make sure the performance still works as designed.
I developed, at the laboratory level, a new product. An announcement was made to the effect that a full-scale batch was to be blended. I requested that all ingredients be shipped to the laboratory for pilot blends. Employer said, “No.” Unfortunately, the full-scale batch failed to pass a crucial performance test. The ingredients should have been shipped to the laboratory for pilot blend testing.
Convincing management that small operations are unable to flush properly between different lubricants during transfer. Key lesson: Management doesn’t understand how the real world works.
Being a newly hired formulation chemist, I received a phone call after office hours. The sales representative from another division was asking how he could warm up a truckload of lubricant, which got hazy after spending several days in the cold. No one else was around in the office, so I looked through the formulation, and 99.5% of its components appeared to have no problem with heating. There was just one additive unfamiliar to me, but I did not think it was worth testing the heat stability in the laboratory. So I explained to the sales representative that storing the lubricant in a hot room overnight should not damage it. Guess what, this 0.5% of unfamiliar additive turned out to be a biocide, which degraded under heat and badly discolored the whole truckload of expensive oil. Even simple processes, such as heating, should be tested in the laboratory first before using them on large systems. As a chemist, I also have learned that degradation of just 0.5% additive in a lubricant’s formulation can lead to major darkening, but this was a very expensive lesson. The degraded lubricant was not disposed of, but reworking it into new batches lasted for more than a year. 
Filtration of a heat transfer system/oil where the oil was severely carbonized. It took far more relatively expensive filters than expected, and it was really a failure. We actually were not able to get the oil clean. Prepare well before commencing a job regardless how big or small the task. A small little thing can have significant impact. 
Adhesive wear of a new steel with too much chromium, which interfered with expected/needed antiwear lubricant additive reaction with surface. Need for more testing earlier in new material development stage.
Poor recommendation for a hydraulic oil that ended in equipment failure. It was fortunate that replacement was reasonable. This situation revealed that I needed to take a closer look at the application. Ask questions concerning application and working environment.
When brand new SUVs had soot coming out of the exhaust/tail pipes after the initial 5,000 km boring-in period oil change. After the boring-in oil change, we (as in my team and I) noticed that the SUVs were smoking even though we had used OEM specification multi-grade synthetic oil 5W-20. After several investigations, we came up with the findings that some of the cylinders on some of the SUVs were leaking compression. We then opened the cylinder heads and measured the accuracy of the cylinder bores and noticed that for those leaking compression, some of the bores were warped. 1) OEM defects were issues to be expected, even from high accuracy assemble and in precision manufacturing plants.
(2.) Calibration is of utmost significance and should have relatively short or routine schedule checks.
Did a lot of work on developing a product for a major customer within their price guidelines, only to learn that due to market conditions, they could not afford to buy the product. Have a cheaper solution ready, just in case.
The application of boron nitride to high temperature jet engine fastener lubrications. What works under very controlled laboratory conditions does not always translate to the manufacturing floor. The transition from the lab to the manufacturing floor was done with proper discussion or lab supervision providing the project a significant black eye from which the project never recovered.
Truly understanding bearing wear and failure modes. Not only depend on the elemental analysis given the alloys present in rolling element bearings, but also look at the morphology of the wear debris under a microscope to learn and understand how these wear particles are produced. It takes time—no one becomes an expert overnight.
One of my biggest failures resulted from not understanding how grease moved internally in a system. The grease type would have been fine, but the consistency should have been specified at a lower number to help flow into the bearings. Always think through the whole sequence of events for your lubrication systems. Asking many questions along the way: What happens if ... happens? What about ...? How might things change if ...? In the grease failure mentioned, the system needed to be reoriented at filling along with specifying a thinner grease.
The importance of air discharge temperature in air compressors and fluid selection. Mineral oils, even really good ones, will tend to produce varnish above 185 F and need to use products with esters or polyalkylene glycols.
We depended on a large international additive company to formulate a finished product in bulk, which separated out various additive packages during the shipment. Key lessons learned were to have more hands on in third-party manufacturing sites. 
The biggest issue I’ve had over the years has been unforeseen additive incompatibilities. The importance of doing lab blends under the same conditions as manufacturing blends.
It involved pipeline monitoring and had nothing to do with tribology. But I learned that what I thought was a sure thing wasn’t as accurate as we needed. Keep looking deeper into the actual results. I don’t think it hurt my growth, and I did learn from it, I hope! 
Using extreme pressure oils in bronze bull gear application. Wrong oil. Manufacturer had extreme pressure oil in its manual. Changed to a worm gear lubricant. Had issues with engineering getting an “outside the manual” lubricant approved for use. Result: new lubricants, and after all gear units were serviced, failure rate decreased by 90%. No more rotten egg, black gearboxes with sponges for gears.
Still unsolved problem of lubricants for machine parts coated with physical vapor deposition coatings despite numerous attempts. Deciding that the problem should be resolved.
Obtaining a fully satisfactory simulation of the high temperature wear damage on a lab-scale, diesel engine, valve-against-valve seat simulator. Improved my ability to design and build custom wear test rigs in the future, especially when accounting for thermal expansion and alignment of the contact surfaces.
The mixture of two incompatible bases of synthetic heat transfer fluids. Although I mentioned that they were incompatible, I was not empathetic enough when conveying the information to the end-user. It helped me to understand that what, from my experience, is too obvious for me is not for everyone. 

My failures resulted in ________ growth than/as my successes.
Less 14%
More 52%
The same 34%
Based on an informal poll sent to 15,000 TLT readers.

I feel comfortable sharing both my successes and failures.
Strongly agree 43%
Agree 51%
Disagree 3%
Strongly disagree 3%
Based on an informal poll sent to 15,000 TLT readers.

Editor’s Note: Sounding Board is based on an informal poll of 15,000 TLT readers. Views expressed are those of the respondents and do not reflect the opinions of the Society of Tribologists and Lubrication Engineers. STLE does not vouch for the technical accuracy of opinions expressed in Sounding Board, nor does inclusion of a comment represent an endorsement of the technology by STLE.