Home /
Search 🔍
the Site
pub Where the world gathers for
plating, anodizing, & finishing Q&As since 1989


Chromate based Paints versus Surface treatments

August 14, 2012

Q. Are there industry standard definitions that specifically define what is a treatment compared to what is a paint. Is there a distinct difference in the definition between chromate based treatments versus chromate based paints. Could it be argued that they are one in the same.

Are Primers considered paints or treatment?

Michael Grant
- Australia, Eden NSW

First of two simultaneous responses -- August 16, 2012

A. Hi Michael,

I don't think that you ever consider chromate conversion processes and paint primers as the same, interchangeable or even equivalent. These coatings are different on so many levels.

Often you will find conversion coatings called up as a key for paint. The typical next coating would be a chromated primer (for Defence and Aerospace anyway).

I don't think you will find specific texts that will tell you that the two processes are not equivalent, probably because the technologies are so very different.

If you want a few references then look in the books section on this site, but maybe as a start you can look at the Metal Finishing Guidebook, The Organic Finishing Guidebook, Electroplater's Engineering Handbook, Canning Handbook just to mention a few to get you going.

Brian Terry
Aerospace - Yeovil, Somerset, UK

Second of two simultaneous responses -- August 16, 2012

A. Dear Michael,

There are chromate post treatments (as chromate conversion coatings over zinc, zinc-nickel, zinc-iron, tin or other metals that can be passivated) that are complementary to electrolytic (or, in some cases, hot dip) surface treatments.

And, there are chromate based paints. Chromate based primers are paints, it is the first layer of coating you must apply, and it is the layer that gives corrosion resistance. Over the primer you apply one or more layers of different paints or topcoats.

Hope this distinction can reply your inquiry! Regards,

Daniel Montañés
Self-Drilling Fasteners Manufacturer - Cañuelas, Buenos Aires, Argentina

finishing.com is made possible by ...
this text gets replaced with bannerText
spacer gets replaced with bannerImages

Q, A, or Comment on THIS thread -or- Start a NEW Thread

Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.

If you are seeking a product or service related to metal finishing, please check these Directories:

Chemicals &
Consult'g, Train'g
& Software

About/Contact    -    Privacy Policy    -    ©1995-2023 finishing.com, Pine Beach, New Jersey, USA