Ask the Expert Question-and-Answer Archive

by Ron Joseph

March, 2007

Quality Control of Paint Finishes

Q: As a producer of laboratory equipment and medical devices utilizing primarily powder coat paint, we are plagued by the subjectivity of individual interpretations as to whether or not a part is acceptable after being painted or should be rejected.  Is there any industrial standard or guideline that establishes objective guidelines for acceptable, quality paint coverage?

Your advice would be most appreciated.

A:  There is no single standard for the appearance of a painted product. Each manufacturer and/or customer needs to establish his/her minimum requirements and then specify these in terms of measurable criteria. ASTM methods are predominantly used for reference, but even as you read an ASTM method, you will find that it allows the purchaser and supplier to negotiate terms of acceptance. Other internationally recognized test methods, such as SSPC, Fed Std. 595b, RAL, etc. are also used.

If you wish to eliminate subjectivity you may wish to write a comprehensive standard specific to your products and provide ranges of acceptability which you or your customers deem to be necessary. Please bear in mind that in writing such a standard you should consider the ease, practicability and cost effectiveness of being able to achieve the desired finish quality. If you place the bar too high, you might out price your product in the marketplace. Moreover, the higher the bar the more rejects you can expect.

Regards,

Ron Joseph