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Where Can I Find Blue Chromate Dye?

I am looking for a dye that is put into my chromate solution that makes the part that is being chromated a dark blue. I know of the blue chromate that gives parts a blue hue but I need a dark blue.

Kevin Nawrocki
- Germantown, WI
2001

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I've seen something that sounds like what you are describing. It was called "metric blue" dye and was used by a hardware manufacturer to distinguish their line of metric bolts from their American sized hardware. But this dye was applied in the erstwhile final warm water rinse tank and was applied to a yellow chromate. I don't know if your blue chromate coating is heavy enough to accept the dye and produce a rich blue color.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2001

Dyeing conversion coatings is an imprecise art. Generally speaking a wide range of colors can be applied to all "colors" of conversion coatings. The darker the conversion coating, the deeper dye color will be achieved. This is not due primarily to the darkness of the coating but rather to the thickness of the film. Therefore, clear/blue coatings lend themselves to pastel colors; yellow and olive drab to deep colors. A variety of blue dyes are available but in view of the above, it would be necessary to use over yellow chromate.

Gene Packman
process supplier - Great Neck, New York
2001

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I do not have direct experience with dyes, but have heard from knowledgable sources that using dyes in conjunction with zinc electroplating are an absolute nightmare to work with. Just thought I would warn you before you went too far with this. If you still would like to try working with dyes, make sure you have good plans for your production process.

Tim Neveau
Rochester Hills, Michigan
2001

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2001

Hi Kevin,

In response to your question, I myself have worked with dyes in the past. The dark blue colour you are looking for is very well achievable. It is applied over a top coat usually a dark yellow chromate or a clear chromate can also be used.

The processes going as follows, Zinc Plate, Chromate, Rinse, Blue Dye and Spin dry. The darker the yellow the darker you can have the blue dye. In the past I have worked with Pavco dyes, it operates best at a temperature of 110 degrees F at a pH of 4.0 to 4.5 and an immersion time of 15 to 60 seconds with an operating parameters od 1.5 oz/gallon. Also if you are doing fasteners you also have the option of using a blue ink with a Torque & Tention Liquid

Hope this hepls you.

Roger Rammass
- Mississauga, Ontario

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I've also used the Pavco blue dye directly over yellow chromated zinc diecast. It can be a pain to keep the color consistent but if you have a slight range of hue to work with it helps. Our operating parameters were the same as Rogers and we would use a warm water leach to help match the color.

Jim Conner
Anoplex Software

Mabank, Texas USA

2001