44027

Finishing Fallout  

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As a Quality Professional of 35 yrs, I have come across various finishing operations done subsequent to manufacture. In each type of finishing operation, each & every Finisher seems to have thier own Fallout % that we, the manufacturer, is suppose to "Allow" for. While I do indeed understand some of this "Tribal" knowledge is based on degree of experience, type of finishing, etc -isn't there some guidelines. For example, Rubber Bonders need 10%, platers need 5 % for parts over 2 sq. feet surface, 10 % for smaller parts, vibra & tumblers need 1%, etc. Is there any uniform guidelines that are used? I am hard put to believe that an Industry that has been in existence for Hundreds of years, hasn't come up with some Standard. But then again, maybe we Quality Professionals aren't being paranoid in thinking the Finishing Industry is keeping it a Secret!

Sharen A Gutierrez
stampings - Stratford, Ct, USA

On the one hand most plating shops will put standard terms in the contract that are in fact negotiable, Sharen. On the other hand, 100 percent satisfactory parts is impossible. So that's what brings you to where you are.

I think 5 to 10 percent fallout would be very high for most plating shops for most types of parts, but consider this case: you ship low quality zinc diecast parts with cold shuts to a plating shop. The parts cost a nickel to cast and a dime to plate. If you ship such parts to the plating shop, what would you have the plating shop do? They are not going to keep trying a 10-cent process repeatedly until they salvage that 5-cent part. Some of those parts probably could have been salvaged if vacuum impregnated before they started, but have you or have you not allowed for that cost, or do you leave it up to the shop to decide which way to quote?

I believe the right approach is to visit the plating shop, sit down with them, and work it all out. But if you want to treat plating of your parts as a commodity, when the parts you ship are variable in their plateability, the problem will continue.

Ted Mooney, P.E.  finishing.com Brick, New Jersey