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Characterizing nano-ceramic paint pre-treatment on the shop floor

2005

I am implementing a nano-ceramic paint pre-treatment coating for powder paint on HRS in a high volume manufacturing facility. This coating is an inorganic coating with a primary ingredient being fluorozirconic acid. I am looking for a way to characterize the coating (determine it is there to begin with and is at the appropriate weight and is consistent all over the part) that the floor operators can perform. The coating shows very little color on the substrate and the coating weight is within the margin of error of a traditional weigh-strip-weigh coating weight test, around 10mg/sq.ft. I am told that the coating weight can be determined using ICP on a known amount of stripping solution by looking for the zirconium after stripping, but of course we don't have ICP equipment and that is beyond the scope of knowledge of our operators on the floor. Why, you might say, are we implementing a process that is difficult to monitor in-house? The decision was made to purchase a 3-stage pre-treatment washer, which we modified to be able to run with separate cleaner and coater (the nano-ceramic) stages without increasing the footprint of the wash (reduced capital cost for a 3-stage vs. a 5-stage). Any feedback would be appreciated.

Lisa Schiller
HVAC--compressors - Lebanon, Missouri

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I would look for a way to titrate the Zirconium metal in the solution after you have dissolved the coating. If there are no interferences, you should only have to do a simple titration, which can be done by most labs. Another possibility is to run the solution from stripping through a cation exchange column and titrate or otherwise measure the amount of [H]+ ion released. search for "titrate zirconium" for ideas.

  
Tom Pullizzi
Falls Township, Pennsylvania
2005

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2005

Hi Lisa,
Is this coating a coating you developed yourself or is it a proprietary product you purchased from a vendor? If it's a product you purchased, I recommend you contact your vendor for ideas on how to do the measurement.

Maybe a better way would be to measure the fluoride in the bath after stripping with a fluoride ion specific electrode, assuming it can be done accurately and that it's reproducible.

Good luck.

Bill Duttlinger
- Naperville, Illinois