Ceramic Coating Basics2 min read

A Coating Trial with No Failures: What Can You Actually Conclude?

Understand what zero observed failures in a coating trial can support, using an exact binomial example and clearly stated assumptions.

Updated · NANOLAB Knowledge

Editorial illustration: A Practical Quality-Control Process for Ceramic Coating
Editorial illustration

“No failures observed” is a valid result. “Failure is impossible” is not. A small coating trial can finish successfully while leaving considerable uncertainty about performance across a wider population.

Define failure and exposure first

Specify the event being counted: unacceptable haze after application, a packaging leak, or failure to meet a defined cleaning endpoint after a stated exposure. Every unit must face the relevant opportunity for failure. Ten panels inspected after different durations are not automatically ten comparable pass/fail trials.

A numerical illustration

For independent, comparable pass/fail trials with a constant failure probability, the exact one-sided 95% upper confidence bound after zero failures is 1 − 0.051/n, where n is the number of trials.

Independent trials with zero failures Upper bound, approximately
10 25.9%
30 9.5%
100 3.0%

These figures describe a statistical bound under the stated model. They are not measured failure rates or forecasts for a particular NANOLAB product. The example shows why a small successful demonstration cannot establish a near-zero field failure rate.

Check whether the assumptions fit

Repeated measurements on one panel are not independent installations. Packs filled together may share a process fault. Vehicles washed by the same operator may share handling conditions. Common causes can make the simple binomial model inappropriate or less informative than the raw sample count suggests.

Also distinguish a completed exposure from a test stopped early. A sample that has not yet failed at an interim inspection may still fail later. Report the exposure duration and endpoint rather than converting an unfinished trial into a lifetime statement.

Use success to choose the next step

A zero-failure pilot may justify a controlled expansion to additional batches, installers or conditions. Identify the largest gap in coverage and test it deliberately. Keep ongoing monitoring in place after rollout.

The strongest report states the sample count, sampling method, exposure and definition of failure alongside the result. That gives customers a useful reason for confidence without claiming certainty the trial cannot provide.

Technical references

The sources below support the stated concepts or describe their own methods. The worked scenarios are editorial examples, not NANOLAB test results.

Ask NANOLAB about your surface and intended use. For application and care, use the current instructions for the exact product.