image description

What about Zirconium, is it good enough to replace Zinc Phosphate as a surface treatment?

What about Zirconium, is it good enough to replace Zinc Phosphate as a surface treatment?

It is well known, for years, Zinc Phosphate has been the best surface treatment to maximize your coatings’ durability. The biggest drawback is the presence of Zinc and Phosphates in your waste water as they are highly restricted by all cities.

Can Zirconium be the next best thing?

Zirconium based technologies for surface treatments have been around for a while and they are rapidly gaining ground because of the following advantages:

  • Good Salt Spray results
  • No phosphate
  • No sludge
  • Simplified process

Some will say Zirconium is great for aluminum and less so for steel surfaces. However, our salt spray tests performed on STEEL plates show that Zirconium obtains results almost as good as a well tuned Zinc Phosphate surface preparation.

See results below, 5 different surface treatments were tested: 1 with Zinc Phosphate (reference), 3 with Zirconiums from 3 different suppliers and 1 with Amines.

These tests were performed by SIXPRO inc. (, an expert in E/Coat and Powder coating application!


Coupons : Hot Rolled Steel panels of 3’’ x 5’’
Coating : Powder coating POLYESTER
Test : ASTM B-117 – results verified as per ASTM D-1654

Zirconium Table

No mechanical agitation of any sort (scrubbing or wiping) was used in this study.


Best results were obtained with Zinc-Phosphate : 1500 hrs at 6 / 10 while the best Zirconiums: #1 &3 obtained 1500 hrs at 5/10, an almost identical result

Zirconium #3 was not far behind with 1500 hrs at 4 / 10.

OVERALL, you can obtain similar Salt Spray results with both technologies. On the other hand, you can eliminate phosphates and simplify your process with Zirconium. Contact Troy Chemical to learn more.