Traditional Zinc Rich Coatings

The traditional zinc rich coatings using zinc dust will typically contain about 70-80% by weight of zinc in the dry film.  While this does provide great cathodic protection, it can also cause things like pores, mud-cracking and pin-holes.

This is all a bit flaky don’t you think?

Research shows that you can reduce the zinc content by as much as 25%-30% and still maintain an excellent protective coating.  This can be achieved by mixing both zinc dust and zinc flake.  The mixture of the two will help prevent the undesirable qualities mentioned above.

Some research has shown that this mixture also has been shown to have a very good pot life of 10-15 hours or more.  Additionally, some of these type coatings have achieved very good salt-spray hours.

It would appear that combining the zinc flake and zinc dust shapes (flakes and spherical) increases the electrical contact between the particles and so maintains great cathodic protection even at these vastly lower zinc loading rates.

Mixing the particle shapes seems to increase the number of electrical contact points between the differing shapes – this is what makes it work so well, even with this lower zinc content.

One such company that makes these zinc flakes is Metal Flake Technologies (MFT).  You can find them on the web at

Zinc Flake SEM Micrograph
Zinc Flake SEM Micrograph

Zinc-rich paints possess similar characteristics to a hot-dip galvanized surface coating. Recent studies at the University of Pennsylvania and University of Wales Swansea have shown that flaked zinc in combination with traditional spherical dust provide equal or better corrosion protection with a lower zinc loading percentage.

We at Purity Zinc Metals are committed to partnering to achieve superior and innovative solutions.

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