I'm a quality/compliance manager in Chemours' industrial coatings group. My team reviews coating specifications, test panels, and production qualifications for the products we sell—roughly 200 programs a year. In 2024, I rejected 12% of first production runs. Most of those rejections had nothing to do with the coating's chemistry. They had to do with what happened to the part before, during, or after the coating process.
Take one case from February 2024. A fabricator in Greensboro, North Carolina, had 8,000 steel brackets rejected by their biggest customer. The brackets came out of their powder coating line looking great: smooth finish, even color, good gloss. The customer's receiving inspection did a crosshatch tape-pull test, and the coating peeled off in flakes. A 96-hour salt-spray test then showed rust creeping out of the scribe marks.
The fabricator asked us which powder had failed. We tested retained samples from their lot. The material was within spec. So we sent an engineer to watch the line, not the lab.
Here is what we found. The oven's display read 395°F. But a data logger attached to one of the brackets showed the part reached 341°F before leaving the oven. The powder's technical datasheet called for 400°F at part temperature for 15 minutes. The coating looked fine because an under-cured thermoset can look smooth and hard at room temperature. It fails later—when adhesion is tested, when the part flexes, or when moisture works its way underneath.
That lesson applies beyond powder. I see the same kind of failure with ceramic systems, liquid industrial coatings, and Teflon fluoropolymer coatings. The product gets blamed for a process problem.
Root cause #1: The thermometer wasn't on the part
'What temp does powder coating need?' is a question I get weekly. The honest answer isn't one number. Most conventional thermoset powders—epoxies, epoxy-polyester hybrids, TGIC polyesters—call for about 350–400°F (177–204°C) for 10–20 minutes at part temperature. Some low-cure powders can cross-link at 275–325°F, but they usually need longer dwell times. Those are general ranges as of January 2025. The technical datasheet for your specific powder always wins.
The deeper issue is the gap between what the oven reads and what the metal actually experiences. A ¼-inch steel plate absorbs heat differently than a thin sheet. Rack density, oven zoning, conveyor speed, and even the color of the part change the temperature curve. The Greensboro line was set at 395°F, but the parts spent only about six minutes in the oven and never crossed the cure threshold. The oven was doing its job. The parts just weren't getting the heat.
The fix is not complicated. Run a thermocouple on the heaviest part you coat, send it through the oven, and look at the time-above-temperature trace. If your process doesn't keep the part above the cure temperature for the required time, no coating material can save it.
Honestly, I'm not sure why more shops don't do this once a week. My best guess is that when parts look good, stopping the line to run a test feels like wasted time. But I've seen the cost of that assumption, and it is not small.
Root cause #2: A product name is not a specification
The second root cause happens even before the coating is applied: people choose a coating type by its name or reputation instead of by what the coated part must actually do.
Ceramic is a good example. I talk to applicators who do ceramic coatings in South Tampa, and customers ask for them by name, especially for vehicles, wheels, and architectural metal. Those can be excellent systems. High gloss, water beading, scratch resistance, and good behavior in hot, salty, humid air are real benefits. But I have also seen people request ceramic coatings when their real problem was material sticking to a roller or a mold. No ceramic topcoat will fix a release requirement as well as a fluoropolymer coating will.
Fluoropolymers are another example. The word 'Teflon' became generic, but not every nonstick surface is a Teflon coating. Chemours Teflon coatings are engineered fluoropolymer systems. They earn their keep when the job needs release, low friction, chemical resistance, or thermal stability. But a thin fluoropolymer film is not a universal armor. If the real problem is corrosion from salt water, an impact-prone surface, or heavy abrasion, a fluoropolymer might be the wrong primary defense. A properly cured powder system or a multi-coat approach could be a better fit.
So stop asking which category is 'best' and start asking what the coated part must survive. If the answer points to Chemours products, great. If it doesn't, the honest move is to say so. I've lost track of how many times telling a customer 'this isn't the right product for that failure mode' built more trust than a forced sale ever would.
Root cause #3: The interface is where coatings go to die
The third cause is invisible, which is exactly why it causes so many surprises.
Here's the story I own. When I started in this role four years ago, I wrote detailed surface prep requirements into every application spec. What I didn't write was a verification step. We trusted that the contract applicator was following the pretreatment schedule.
Then a 50,000-component order failed salt spray. We tested the topcoat chemistry. It was fine. The failure was at the interface: the metal under the coating was contaminated. The applicator's pretreatment bath had lost strength, nobody had checked it, and the coating never truly bonded.
We didn't have a formal audit for that. It cost us a $22,000 redo and a three-week launch delay.
After that, I implemented a verification protocol. No program gets signed off today without three things: a documented surface prep check, a cure trace from an instrumented part, and an adhesion test result. First-pass acceptance across our qualified applicator network went from 71% to 96% within about a year.
The real price of a hidden process problem
In the Greensboro case, a single data logger run before production would have caught the temperature gap in about an hour. Instead, the brackets were shipped, rejected, stripped, re-prepped, and recoated. The direct cost easily crossed $22,000, and the schedule slipped by three weeks. That does not include the customer's lost confidence.
In a humid coastal environment—say, around Tampa or any salt-air market—the consequences multiply. Once moisture gets under a poorly bonded or under-cured film, corrosion runs along the interface and the damage stops being cosmetic. It becomes a structural liability.
But the bigger cost is the story the failure tells. When a quality inspector finds coating peeling off a part, they do not usually ask whether the oven was calibrated. They ask whether the supplier is reliable. That is a hard reputation problem to fix.
Before your next coating job, check three things
There is no single best coating. But there is a repeatable way to avoid the failures above:
- Measure the part temperature, not just the oven temperature. Use a data logger and keep the trace with your batch records.
- Define the function before you name the chemistry. If the need is release, low friction, or chemical resistance, qualify a fluoropolymer like Chemours Teflon coatings. If the need is corrosion and weather protection on steel, powder coating is a proven route. If the need is maximum gloss and scratch resistance on an appearance part, ceramic systems deserve a close look.
- Verify the surface preparation. Check bath records, cleanliness, and adhesion before production, not after the warranty claim arrives.
Specific cure ranges and product formulations evolve, so treat the numbers in this article as a starting point—not as a substitute for the current technical datasheet. But the broader lesson won't change: when a coating 'looks fine and fails anyway,' the problem is rarely the label on the pail. It's the process behind it.