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Multi-Step Coloring

by Dakota 8. August 2016 09:01

Multi-step Coloring

Mitch Kohanek

A multi-step wood finishing schedule is for custom coloring. Obtaining a visual presentation on wood that goes way beyond “brown and shiny”. Color(s) built on top of color(s) that attracts the customers’ eye.

There are basically only three coloring agents to choose from, one of them being on the exotic side. Those three are pigments (which I refer to as stains) dyes (which are not pigmented) and chemical coloring. Chemical coloring, sometimes called “reactive” coloring is the exotic coloring agent is not widely used. The use of chemical “reactive” coloring is to create colors dyes and pigments can’t. The chemicals used will react the woods chemistry such as the tannin's. Since it is a chemical reaction the color presentation is not as predictable as using dyes and stains.

Dyes by nature penetrate into the woods structure. Consider them “molecules” of color. The solvent of the dye dictates how deep it penetrates into the wood. The first use of a dye in the coloring process is to change the base color of the wood. Poplar wood is naturally a light tan (sapwood) and a greenish heartwood. A green dye used as the base color and a “reddish” dye on top of that can produce a warm brown hue.

Pigments by nature lay on top of the wood shifting the colors of the large and small pores. It can be a great advantage to have dyes and stains (pigments) that have the correct chemistry so that they can be mixed together and then applied.

Glazes are normally pigmented coloring agents that are applied on top of a coating. Reasons for using glazes are for accented coloring in the recessed areas of the object. They also can create a depth of color even though there can be a loss of transparency.

Toners are made by putting color into the coating before you apply the coating. If you understand the color wheel, toners can be made to correct colors that are already applied to the object. Toners can lay down a “blanket” of color on the entire piece or selective areas. They can hone in sapwood to heartwood or correct the entire object if the color is not the correct hue.

So a finishing schedule may look like this.

Walnut substrate

1. Dyed yellow

2. Stained burnt umber

3. Sealed

4. Scuff sand

5. Glazed raw umber (cools the color and color strikes the larger pores a darker color)

6. Topcoated

7. Scuff sand

8. Amber toner

9. Topcoat without exceeding the recommended dry mil thickness

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