Black Trivalent Passivate & Hexavalent Chromate Conversion Coatings


GLMF’s zinc electroplating with trivalent black passivate and hexavalent black chromate results in a dark, consistent black finish over the entire part. With our automated zinc electroplating lines and on-site lab, we are able to give dependable results from the first part processed to the last piece off the line.


Trivalent Zinc Yellow Passivation Plating & Yellow Hexavalent Chromate  Coating


Our unique trivalent yellow passivate is ideal for our customers who require their products to be ultraviolet (UV) stable as our coatings do not contain dye. This feature ensures that the electroplated parts will stay true to color in the sunlight. The trivalent passivate iridescent yellow cast will visually compare with the Hexavalent chromate color, however the hexavalent chromate has self-healing properties in the event that small scratches occur.


Clear Trivalent Chromate Conversion Coating


Great Lakes Metal Finishing, Inc offers many clear zinc plating options, all of which are trivalent and are RoHS compliant. The main distinguishing factor between these electroplating options is the difference in corrosion protection. Not including any available topcoats or sealers, our clear zinc coatings can give a minimum salt spray protection of 12, 96, or 250 hours to white corrosion, depending on the trivalent passivate used.


Olive Drab Hexavalent Chromate Conversion Coating


Great Lakes Metal Finishing, Inc has developed a proprietary olive drab chromating process that removes the inherent iridescent appearance from the olive drab finish. The process produces an even, matte finish, which is required for military operations. The olive grab chromate was developed to match olive drab paint, thus greatly reducing the cost for an olive drab finish.


Zinc Nickel Chromate Conversion Coating


Alloy electroplating offers outstanding salt spray protection. At Great Lakes Metal Finishing, Inc we offer both low and high zinc nickel plating. Higher nickel content is ideal for outdoor industries seeking more than 1,000 hours protection to red rust and superior strength. Even our low zinc nickel alloy coating has greater than 700 hours to red rust and still adds a formidable layer of defense.


Stainless Steel Passivation


While naturally corrosion-resistant, stainless steel is still susceptible to rusting due to environmental conditions. Great Lakes Metal Finishing’s stainless steel passivation process includes the use of nitric acid-based (Nitric 1-5) baths to create a protective layer that shields the product from dirt and other corrosive elements, preventing oxidation. Treating the surface with a stainless steel passivate enhances the formation without affecting the stainless steel itself.

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Other Metal Finishing Services

Aluminum Chemical Conversion

Great Lakes Metal Finishing offers a semi-automatic rack line to process aluminum parts with a Qualified Product Listed (QPL), QUALICOAT, and GSB approved trivalent clear passivate. Our process meets and even exceeds MIL-DTL-81706B and MIL-DTL-5541F for bare corrosion resistance, class 1A.

Zinc Color Dyeing

zinc color dyed parts
Great Lakes Metal Finishing can dye your zinc plated product for part identification and/or for visual appearance. Your choice of color includes: blue, red, green, or yellow. The aesthetically pleasing dye is applied over a thick film trivalent clear passivate that will provide 96 hours or more to white corrosion.

Stainless Steel Passivation

Our passivation process follows ASTM 967 and ASTM 380 specifications. We offer Nitric 1, Nitric 4 or Nitric 5.

Glass Bead Blasting or Sandblasting

Great Lakes Metal Finishing has two abrasive blasting cabinets. We offer both glass bead and sandblasting to remove weld scale and rust from your parts.

Stress Relief and Hydrogen Embrittlement Relief Baking:

Great Lakes Metal Finishing has several ovens to provide any of your “embrittlement relief bake” or “bake-out” needs up to 500 Fahrenheit (F). By performing a relief bake, you achieve higher load bearing capacities.

Pickle and Oil

Remove rust, scale, and other inorganic contaminants from your parts by contacting Great Lakes Metal Finishing. We test our “pickling solution” daily to ensure your product leaves immaculately clean and with top-notch resilience. Chemical rust pickling of steel parts and the application of a dry touch oil is essential for quality products.

Masking Parts

Customer parts can be masked with plugs, tape, and/or chemical masks before plating. If you have holes, cavities, or a certain area of a part that cannot be plated we mask it for you.

Packing of Finished Parts

Great Lakes Metal Finishing can eliminate part to part contact and damage during shipping by protecting your product with various in house methods. As an example, parts can be wrapped in packing paper, volatile corrosion inhibitor paper (VCI lets moisture escape), corrugated paper, cardboard, and/or foam layers.

Salt Spray Testing

Great Lakes Metal Finishing has its own salt spray cabinet to test corrosion protection on customer parts. Parts can be tested for both white and red corrosion.

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add the next level of protection to your parts, contact us today