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Q&As since 1989


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Metal Coloring, Aging, and Patinas

I am a furniture designer looking for a sheet metal to form as table tops. I want something in the silver colored family. I have tried things such as brushed and beadblasted stainless and aluminum, but find them sterile looking. I want something that I can manipulate the metal to get a patina with some character to it. Nothing dramatic, but a slight aged look to the metal. The coloring of metal books I have read seem to focus on coloring brass and copper. Can aluminum be colored or aged? How about zinc or pewter? But I have not been able to find them in sheets large enough to make a 36" x 84" top. Can you powder coat say zinc on aluminum and get the properties of zinc?

Thank you,

Bill Eastburn
- Sellersville, Pennsylvania

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The term "powder coat" usually refers to organic paint-like coatings; zinc and other metals are usually applied by electroplating. How about silver plating or tin plating?

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

I would suggest if you want to explore something unique that you look into Monel metal sold as Nickel alloy 400. It is available in sheet form. It is very corrosion resistant (69% nickel and 27% Copper). It is approved for Food equipment use. IT weight it is heavier than stainless steel and has a similar appearance. It should be possible with the right chemicals to obtain some patina. I have no further information at this time. It is not cheap and will cost several hundred dollars but it is great for all soldering and welding operations and will last a lifetime. You would need to bond a thin sheet to a supporting material.

Marc Cimolino
- Snohomish, Washington
 

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YES YOU CAN GET A LOT OF colorS PUT ON ALUMINIUM BY THE ANODIZING PROCESS AND IT IS POSSIBLE FOR YOU TO GET AS MANY colorS AS AVAILABLE IN THE SPECTRUM OF colorS . YOU CAN ALSO HAVE MULTI colorS ON THE SAME ALUMINIUM PLATES .

THERE ARE AT LEAST 7 DIFFERENT TYPES OF GOLD , 5 BLUES( ROYAL, SKY, NAVY, AQUA, TURQ), 5 REDS, 5 BLACKS, 5 BROWNS INCLUDE TEAKWOOD, ROSEWOOD , MAHOGANY WOOD, BITTER CHOCOLATE colorS AVAILABLE.

H.KHATAU
- Bombay, INDIA
 

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Use a sample piece of stainless sheet about a foot square. Try 304 it's harder but durable, with a relatively good corrosion resistance factor. Ask a metal plater to dye passivate. This procedure will color the metal and adhere it to the surface. I suggest bead blasting the surface before coating to improve strength, adhereability and corrosion resistance. If you desire, you may have an artisan who could polish or scrape a design on the finish surface.I manufacture a lot of stainless parts for optical application and this is a common process, however a plater who will provide you with this application is rare.

Good Luck,

Daniel Slack
- Woburn, Massachusetts
 

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Have you tried using a torch / heat, some colors can be obtained. With mild steel many colors can be obtained.

Good luck,

Bill Mashburn
- Hermiston, Oregon

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2000

You can color aluminium directly(without anodizing)!

Black for aluminium:

ammonium molibdate.........10 gm

sodium thiosulphate [on eBay or Amazon] .........5 gm

water......................1 lit

Hot immersion(100 C)!

Gray for aluminium:

sodium chromate.......10 gm

sodium carbonate / washing soda [affil links](calc.) 4 gm

potassium hydroxide...4 gm

water..............10-15 gm

Chemical oxidizing!Mixture must be brushed on object and then after 20 min rinse thoroughly!

Goran Budija
- Cerovski vrh Croatia