Where the
world gathers for metal finishing
Q&As since 1989


-----

What's best prep for 416 SS bars before plating with Electroless Ni/Teflon?

April 22, 2009

I produce a line of Kingpin locks that use a 416 SS locking bar. The Ni/Teflon prevents corrosion and teflon's lubricity helps in winter field use versus bare SS.
What preparation(s) would you recommend for best adhesion of plating. Bars have outdoor exposure. In use they are moved slowly by hand in a greased iron bore.

My adhesion concern is just from prior experience with plated parts getting peeling problems.

Thanks

Earl De Young
Product & machine designer - Geneva, IL, USA

---

April 27, 2009

Nearly every plater that can do nickel teflon will have a suitable system for the plating. The care of the solutions, the operator and the QC system will normally be the cause of plating problems.
I do not think that a woods nickel strike would be necessary, but it surely would help IF it was properly rinsed afterwards. Excess chlorides degrade the EN solution.
You do not have a lot of choice of platers for this process, but I would want them to provide information on what QC testing they will do on your parts. I would also send some identified reject parts for them to plate and for you to do your own testing on.
An honest conversation with your plater normally will bear good fruit.

James Watts
- Navarre, Florida

Treat the 400 series stainless the same as 300 series. that is clean, use a woods nickel strike followed by the plating you desire. Contact me if you want more details. Don Baudrand Consultant - Poulsbo, Washington (Don is co-author of "Plating on Plastics" [on Amazon or AbeBooks affil links]            and "Plating ABS Plastics" [on Amazon or eBay or AbeBooks affil links]) April 28, 2009 April 28, 2009 Hi Earl, I gather the EN plating will be done by a plating shop? If so, a shop that specializes in EN plating will have a good process in place to plate EN over 416ss. It depends on the shop doing the work, so it may vary slightly from this basic process. 1) Hot Alkaline soak clean 5-10 min then rinse 2) Cathodic clean 1-2 min then rinse 3) Acid dip then rinse 4) Woods Nickel strike then rinse 5) Proprietary process for EN prep / plating line Mark Baker Fellow Plater - Syracuse, NY USA