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world gathers for metal finishing
Q&As since 1989


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How is an "oil-rubbed" bronze finish attained?

What is the procedure to achieve an Oil-rubbed bronze finish from mill finished CDA 385 Architectural Bronze?

Which is most weldable (either MIG or TIG) and would produce the best looking handrail: CDA 385 Architectural Bronze or Silicon Bronze Alloy 655?

Dan Donovan
welding - Sequim, Washington
2002

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How do I achieve an oil rubbed finish on nickel aluminum bronze? I don't have the ability to dip the object that I am working on into a tank, it must be a hand or brush applied technique.

Jim [last name deleted for privacy by Editor]
architect - San Diego
2007

Reproduction of antique lanterns. Please notify on how to achieve bronze finish over brass product on wet humid condition

Aheer Mohsin
proprietor - Dhaka, Bangladesh
April 5, 2008

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First, Silicon Bronze is far easier to weld than architectural bronze, regardless of what welding method you are using. Architectural bronze is essentially yellow brass with a small change in the zinc content... but the zinc content is still around 40%. Sometimes there is also lead, although I believe this has been removed from the modern alloy mix. When I do weld on 385, I prefer TIG and use silicon bronze filler wire; the zinc just fumes out of standard brazing rod, so no matter what you use you will not match the color perfectly. Silicon bronze does not fume when welding, and you can match the colors perfectly, but has the downfall of not being available in many of the more interesting profiles... basically just rounds, squares, and flats.

As to the finish, any brass, bronze or copper can be darkened using a standard bluing solution, such as the Iron and Nickel Black from JAX. This will take the finish to a dark blue/black, and this is highlighted and relieved as desired using a fine scotchbrite pad. It may take a couple rounds to get the desired effect. We finish off with a paste wax coating, which is buffed with a cloth to a high finish.

Peter Swarz-Burt
Falling Hammer Productions, LLC - Oakville, Connecticut, USA
November 19, 2010