Metal finishing Q&As since 1989

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Coating copper to inhibit tarnishing. How?

2004

We are a volume metal stamping company and have recently started to produce a product from copper which will be used outdoors.

The requirements from the customer are that the part receives a coating that inhibits tarnishing but does not change the natural colour. We have never worked with copper before and wrongly assumed that it could be coated in the same way as many other products we produce, Powder coat. However we have now found out that although we can clear coat the oven temperature that it gets baked at changes the colour. It was then recommended that we have them clear lacquered, but this at them moment is more than double the cost of Powder coat.

We were wondering if there was some other coating that could be applied, that we could, preferably do in house as we process the parts. Marking of the parts is also a problem and the less they are handled the better. Any help would be very much appreciated.

Robert Farr
President - Vancouver, BC, Canada

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You can use Incralac [on eBay or Amazon] - special lacquer for copper and its alloys (Paraloid B44 acryl resin and some benzotriazole as corrosion inhibitor-USA product)!

Goran Budija
- Cerovski vrh Croatia
2004

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2004

Hey Goran,

I hope Incralac [on eBay or Amazon] is paying you! Contact me if you would like to do some rep work in Croatia.

Jake Koch
G. J. Nikolas &Co.,Inc.

Bellwood, Illinois

Ed. note: While we always prefer suggestions for generic types of material rather than brand names, Mr. Koch's reply should remind the readers that it is G.J. Nikolas and our other supporting advertisers who make this forum possible for you, and that they are a highly reputable supplier of specialty lacquers who can offer the type of products mentioned.