Paint Testing Information

Q. I am a chemist for a paint supplier. I need to test a paint on steel panels and production parts and send them to an independent laboratory for testing. Full cure for the coating is: Air dry for seven days at 77°F or oven cure 40 min at 220°F+24 hr air dry. The following describes some of the tests we need to have for a customer: color match, cross- hatch adhesion, 60° gloss, impact resistance, solvent resistance, corrosion resistance (salt spray), pencil hardness, chemical and stain resistance, humidity resistance, mandrel bend, abrasion resistance, and QUV exposure. The test parameters are listed in the attached data sheet.

At what dry film thickness should the panels be sprayed for testing? Should the supplier paint the panels or should I have to? Do the panels need to be painted on both sides?

Since we need to use an independent testing laboratory, can you recommend one? R.A.

 

A. Congratulations on an excellent paint performance specification! Owing to space constraints, I can not list the test parameters. When I was the paint consultant at Westinghouse Research Labs., we specified a dry film thickness of 1 mil (0.001 inch) for each coat of paint on all test panels. I recommend you do the same unless your customer specifies otherwise. Since some of the panels corrode during testing we always painted both sides. I always painted panels for performance tests in my laboratory to assure they were prepared correctly. The only time panels were prepared by others was when the paint required special application equipment or the end-user insisted on doing it himself.

Independent testing labs are listed in the Products Finishing Directory under Testing Laboratories, Independent, paint finishes. They are also listed under the same headings at www.pfonline.com.