Automated Zinc + Trivalent Black

Varland Plating started working with trivalent black chromates over 17 years ago, in 2007. At that time, we encountered significant challenges while learning to perfect the process to the point where it could compete with hexavalent black coatings already on the market. We experimented extensively with different chemistries from different suppliers over the years in pursuit of a solution that would meet our standards and the needs of our customers, but we were never completely satisfied with the consistency and quality of the product.

In 2017, one of our chemical suppliers released a new product that reignited our optimism. We immediately saw appearance improvements, and we spent the next two years refining the process to ensure we could produce consistently excellent results.

Despite seeing improvement, complete satisfaction remained elusive. In 2019, Varland installed a chloride zinc plating process with propelled our trivalent black process to new heights. After fine tuning the chemistries, we reached a level of appearance comparable to hexavalent black while also providing benefits like reduced toxicity and superior corrosion protection.

There were still hurdles we had to overcome, namely perfecting the process across the wide variety of parts we process as a job shop. In particular, flat parts like washers tend to stick together in the barrel preventing optimal chromate coverage. The solution to this problem went beyond chemistry and procedural adjustments to engineering special barrels for post dip operations of these challenging parts.

The final hurdle, completed in 2023, was automating the trivalent black process. Automation is critical not only for quality and consistency, but also for efficiency and scale, allowing Varland to match outstanding quality with competitive pricing.

All of these refinements over the years have led to a product that receives overwhelmingly positive customer feedback as our customer/part base has grown. Our exhausive experimentation and rigorous internal standards have made us true experts in zinc plating with trivalent black chromate.