steven J

Topic: Trivalent Black Chromate

Hi, I was just looking for opinions on what platers think is the best trivalent black chromate out on the market. We use alkaline non-cyanide zinc and zinc iron baths to plate our parts. I am currently running Dipsol's black and am pleased with it. But I am always looking for the next best thing. If possible please include salt spray hours to white and any other specs. Thank you.

Last edited by steven J (01/14/2009 - 04:00 PM)

DustinGebhardt

Re: Trivalent Black Chromate

I've had a lot of success with A Brite's tri-black over acid zinc and alkaline non-CN zinc. I've not tried it over Zn-Fe. I can't recall the corrosion specs right now, but you can give them a call at 214-291-0400.

-Dustin Gebhardt, CEF

Advanced Manufacturing/Finishing Engineer

Moen

Sanford, NC

jamie b

Re: Trivalent Black Chromate

Hi Steven,

Most of the Trivalent blacks out on the market are based on the same technology. They consist of 2 parts, one tri-chrome portion and the other an iron based portion. They were developed around 6 years ago and some improvements have been made.

Over a year ago we switched from your kind of system to a non-chrome black from PAVCO and have had excellent success running it over chloride zinc barrel. The color and deposit rivals the old hexavalent black look. We basket dip full barrel loads ~75 ft2 per basket. There is a system for alkaline zinc plating and I would think the salt spray would preform as well or better than cloride. The operation consists of maintaining ph 4.5-5.0 and uses a one part maintenance addition. The final tank is a sealer that provides protection that ranges 96-120 white salts.The system is easier to operate and maintain than the tech sheet describes.

You can contact me with any questions about this process or you can call Pavco direct.


Jamie Baldwin
Triplex Plating

B.L.AGARWAL

Re: Trivalent Black Chromate

We would like your opinion on the following matter:


We are using Alkaline zinc plating with Traivalent passivation on couplings being manufactured at our plant. The couplings are used in manufaturing Hydraulic Hose Assemblies for Heavy Earth moving machinery, Machineries used in Steel plant and underground Mining Machinery. The couplig(Ferrule) is CRIMPED on Rubber Hose. We request you to favour us with International standard being adopted to check rusting (white rust/Red rust) during salt spray test, Please also advise us the chemical to be used for enhancing corrossion resistence.


Regards


B.L.Agarwal