Some recent questions about using dye prompted me to post this very basic introduction to dyes and their use.
Dye is a crystal that dissolves in a particular solvent. Many are sold in powdered form; others are pre-dissolved and sold in highly concentrated liquid form. There are also further diluted, ready to use, already mixed dye based stains, and if you have good luck with them, by all means use them. However, to my mind, the most valuable aspect of dyes is the complete control one has mixing them from either powder or liquid concentrate, and that’s the route I would suggest.
Powders usually mix in only one of three solvents; water, alcohol or oil (petroleum solvents). Liquid concentrates, usually sold in small, two ounce squeeze bottles, will usually mix in both water and alcohol, and possibly some petroleum solvents as well. The easiest to use dye solvent is water, so let’s start by learning to use water soluble dyes.
Controlling color density: To make a stronger color dye, mix more dye into less water. For a weaker dye, add more water and less dye powder. You can mix various dyes to make custom colors as well.
Applying dyes: The most important thing to remember is that the amount of color a dye imparts to the wood is not controlled by how you apply it, but rather by how you mix it. This is the opposite of pigment stains, which can be controlled during application.
The best way to apply a dye is to flood it liberally onto raw, sanded wood, then wipe off all that you possibly can, leaving only what the wood has absorbed. You can create serious bleeding and adhesion problems putting some dyes over some finishes, so for now, work only on raw wood.
Start with a weaker color of dye than you think you want. Dilute some of your dye mixture, but save some at full concentration just in case.
Reapplying the same density dye a second time will not substantially change the wood’s color, since you already allowed it to absorb all the dye it could before wiping off. To get the wood to take more dye, you must mix a stronger version (more dye, less water) and stain again, right over the original dye and in the same way, flooding and wiping. You can also apply the stronger concentration selectively to only some areas to adjust lighter colored boards to match darker ones, or to color sapwood to match heartwood.
Thorough wiping is very important, since dye left on the surface will revert back to a powder when it dries, making a surface that is difficult for finish to adhere to.
Check the color while the dye is wet, just after you wipe it off. It will change color and become chalky when it dries, but the original wet color will return once you add clear finish. When the dye is dry, seal it with finish that uses a different solvent than the dye. That prevents dye from being dissolved by the finish and bleeding upward into it. For water soluble dyes, I use Zinsser SealCoat prior to waterbased topcoats. Solvent and oil based coatings can go directly over dried water soluble dyes.
Michael Dresdner
straight talk about wood finishing
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