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How to judge whether plating passes B117 12 hours or 96 hours?

2006

Many times I saw clear zinc plating can pass ASTM B117 12 hours and yellow zinc plating can pass B117 96 hours. According to ASTM B633, it does.

but I have question, what does B117 12 hours or B117 96 hours mean since B117 is just a test method and doesn't specify the rusting degree (the rusting degree specified by ASTM D610 ) ?
I just want to know at how much rust area is allowed to pass B117 12 hours test ? Can you guys please tell me?

thanks,

John

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No rust is permitted.

Corrosion resistance requirements are given in ASTM B633 "Standard Specification for Electrodeposited Coatings of Zinc on Iron and Steel." After salt spray, Types II & III coated specimens "shall show neither corrosion products of zinc nor basis metal...visible to the unaided eye at normal reading distance" except white corrosion at edges.

Ken Vlach [deceased]
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
2006