The colors produced appear in up to five repeating orders. Most of the current jewelry is produced with the first two orders. All the colors of the light spectrum are not produced. True red and forest green are not generated.

When the oxide is of a thickness to generate interference colors, its depth is measured in angstroms (Ã…=1/100,000,000 centimeter). This layer can vary in thickness from 500 to 1,000Ã…+ depending on the color. It is not the oxide itself that is perceived by the viewer but its effect on light.

Although harder than the parent metal, the extreme thinness of this oxide dictates that it is not a strong wearing surface. Bracelets, belt buckles, rings and items that normally receive heavy abrasion should not be considered unless the metals are protected by other design elements.

Thermal oxidation

Throughout the thermal coloring process cleanliness is an absolute necessity! Dirt, dust, oil and finger prints will discolor the oxide as it is growing. It is possible to contaminate the surface for special effects. Refinishing a piece that has discolored during the heating operation is difficult and time consuming. Niobium does not heat color. When heated to a dull red and held for 10-15 seconds it will produce a tough gray/black oxide. This is a very hard finish and works well in many applications where a black metal is desirable. The piece must be formed first because heating hardens the metal. The black oxide can be polished, waxed and even engraved and anodized.

Flame coloring

Kiln coloring can be done in a standard enameling kiln. Running at temperatures between 800 and 1,200 degree F, a few minutes in the kiln will produce golds, purples and blues. Actual temperatures and times will relate to the size and thickness of the metal. Solid one color pieces can be produced with this method.

Disclaimer of Liability

Reactive Metals Studio, Inc., ArtMetal, and the author assume no responsibility and disclaim all liability for injuries and /or damages and/or loss of profit from the use or attempted use of the processes described in the following paper.

About the author: Bill Seeley is president and founder of Reactive Metals Studio, Inc. He is considered an expert in this field with over fourteen years experience as artist, teacher and consultant. This excerpt was compiled from "Studio Preparation and Coloring of Titanium" Bill's Masters Thesis completed at the University of Kansas. If you have questions please feel free to call 800/876-3434 or FAX 520/634-6734.

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Copyright 1994, 1995 ArtMetal

Author: Bill Seeley

ArtMetal Editor/Curator: Enrique Vega

Last Updated:Sun, Jan 21, 1996