Supplier's First Run had Plating Problems - Can they Strip, Re-Plate and PPAP them?

[vardar3]

Our supplier called and said his first run parts came back from the plater and the platting was soo thick it made the diameter oversized. He has unplatted parts that are fine.

Can he use these parts to PPAP, if he sends them to have them stripped and replatted?

What if this was the only run scheduled for a long time (PPAP due middle of April). What should I suggest so he can PPAP?

[Jim Wynne]

In Reply to Parent Post by vardar3

Our supplier called and said his first run parts came back from the plater and the platting was soo thick it made the diameter oversized. He has unplatted parts that are fine.

Can he use these parts to PPAP, if he sends them to have them stripped and replatted?

What if this was the only run scheduled for a long time (PPAP due middle of April). What should I suggest so he can PPAP?

I take it there aren't enough unplated parts to use as representative of the PPAP production run? Technically, the PPAP "significant production run" is supposed to be representative of the supplier's normal production process. Having to send parts back to the plater in the first run is evidence of not being ready for production. The plater is your supplier's responsibility, and process control is not in evidence.

I think I would allow the parts themselves to be stripped and replated, but I would also expect to see some information on how the plater has corrected the situation. You might want to consider interim approval for that reason, with full approval coming after the next production run, assuming the process doesn't crash and burn again. Kudos to your supplier for divulging the information--he could have just had the parts replated and said nothing.

[vardar3]

He had more parts to send to plating and evaluate so it will be easy to get around considering plating is good. Thanks for the advice.

[Jim Wynne]

In Reply to Parent Post by vardar3

He had more parts to send to plating and evaluate so it will be easy to get around considering plating is good. Thanks for the advice.

That doesn't alter the fact that the plater screwed up. Tier 1 suppliers are supposed to flow down the production part approval process used by the end customer, so your supplier should have PPAP in hand from the plater. If that PPAP indicates that there was no problem, there's a problem.

[Wes Bucey]

In Reply to Parent Post by vardar3

Our supplier called and said his first run parts came back from the plater and the platting was soo thick it made the diameter oversized. He has unplatted parts that are fine.

Can he use these parts to PPAP, if he sends them to have them stripped and replatted?

What if this was the only run scheduled for a long time (PPAP due middle of April). What should I suggest so he can PPAP?

Having been in the high tech contract machining business, I know a lot about the possible problems with plating of all types and a lot about fixing those problems or avoiding them in the first place.

Jim is correct that the plating is your supplier's problem (to cure now and avoid in the future.)

Depending on the plating and the tolerances involved on the product, it is unlikely the overall thickness of the plating on every surface of the product was too thick. If it was electroplating, there is an effect called "dog boning" which can occur on sharp edges and points of products which can result in a much thicker deposition of plate, skewing the dimensions of the product.

Another problem which might have occurred is that the product was dimensioned too large prior to plating and normal variance could have skewed results.

If I were you, I wouldn't settle for less than a complete root cause investigation (with participation by both your supplier and his plater) to determine precisely what went wrong and how it will be successfully avoided in the future.

Let me hasten to say, "Don't be too quick to allow all the blame to settle on the plater until the root cause investigation is complete."

Just out of curiosity: What was the plating and the thickness specification? Did the plating company also run test pieces of "coupons" for destructive testing to confirm the plating thickness met spec?

I was obsessive about plating and vetted my platers as closely as I vetted the guys who married my daughters! In over ten years, I never had the same plating problem occur twice and never failed to resolve the problems I did encounter.

[learnever]

Thanks all!

Some interesting points to learn, plating amny a times is taken lightly, but should not be.

Have a good day!

Thanks again.

[vardar3]

Plating thickness….That is something that is not referenced on our print, and I don’t see it in the material spec GM 4435M. I see weight, (g/m2MIN) where should that be called out at?

We have a few suppliers going through the initial submission. They all have the GM4435 plating Code A. As I am reading the specification I see there are a few tests that should be complete, like:
· GM4435P-humidity testing
· GM9071P-tape testing
· GM4298P-salt spray

When I look at some initial submission from other plater (I’m new to PPAP) all I see is testing to the salt spray 72 hours, should they be completing all these test???

[Jim Wynne]

In Reply to Parent Post by vardar3

Plating thickness….That is something that is not referenced on our print, and I don’t see it in the material spec GM 4435M. I see weight, (g/m2MIN) where should that be called out at?

We have a few suppliers going through the initial submission. They all have the GM4435 plating Code A. As I am reading the specification I see there are a few tests that should be complete, like:
· GM4435P-humidity testing
· GM9071P-tape testing
· GM4298P-salt spray

When I look at some initial submission from other plater (I’m new to PPAP) all I see is testing to the salt spray 72 hours, should they be completing all these test???

GM 4435 calls for zinc phosphate plating, and yes, your suppliers should be doing all of the prescribed testing. If your purchase orders call out the GM spec, they have no excuse for not doing it. In general, when there is no plating thickness callout, the expectation is that the plating will be sufficient to pass the corrosion testing (humidity and salt spray).

Your plater may have erred on the side of caution by overplating the parts. They need to work out their process--it's really a matter of validation--such that they know that their plating parameters will produce output that (a) doesn't result in dimensional issues and (b) is sufficiently corrosion-resistant.

This is something that should have been worked out between you, your tier 1 supplier and the plater, in that in order to avoid dimensional problems the proper preplate dimensioning should be established.