Whenever you handle dyes, you must protect yourself and take steps to guard your health. Among other things, you need to avoid absorbing dyes through your skin, and avoid inhaling powders or fumes when mixing or heating dyes by using approved protective measures. You should become informed of possible health risks such as cancer of the liver or kidneys that might result from using certain types and categories of dyes.
Done properly, and following the dye manufacturer's guidelines, dyeing can be a safe process. There is a wealth of information in Product Data Sheets available from manufacturers, suppliers, and government publications. The Internet may also provide information, but be careful that it comes from a reliable source. Do your homework!
Determine what mordant you will use. A mordant is a substance that has the effect of "setting" a color to make the color lightfast. All colors will eventually fade somewhat over the long term, but mordants will delay this fading effect for some time. Many substances may be used as mordants to set colors. You may remember your great grandmother dyeing material over a heated vat. Chances are that she used salt (sodium chloride) or vinegar (acetic acid) as mordants. A common mordant used for centuries is "alum" (aluminum potassium sulfate). "Lime water" (calcium hydroxide) is another commonly used mordant.
Choose your mordants carefully. Some mordants can be very dangerous such as; copper acetate/salts; mercuric sulfide, lead oxide, arsenic trisulfate. The names alone should be sufficient warning for you to stay away from such chemicals. Our choice of mordants was magnesium sulfate, commonly called "Epsom Salts." It was satisfactory for our purposes, and readily available in local food and drug stores.
"Dyes" are present in many substances, some natural, and some synthetic. Many organic dyes come from plants, such as: roots, bark, flowers, berries, leaves, and vegetables. However, the colors are usually difficult to duplicate because of the nature of their sources. This type dye is usually used for dyeing small batches of fabrics, wool, etc. Plants do not always give the same results in shades, hues, tints, tones, colors, etc., because of various conditions including where the plant grew and soil conditions. Natural dyes are usually not consistent from batch-to-batch. These dyes would not be a good choice for dyeing wood and inlays on a consistent basis.
Synthetic dyes, on the other hand, are manufactured in large quantities and in a great variety. Colors are also more uniformly duplicated from batch-to-batch. But there are some drawbacks to using synthetic dyes. How do these chemical dyes affect the environment? How safe are they to a person's health, e.g., children chewing on dyed products? Some of these dyes can be dangerous in this respect. Others are safe to use when you apply common sense precautions and follow the manufacturer's Product Data Sheet recommendations.
One group of chemical dyes is the aniline dyes manufactured from coal tars and oil. Manufacturers produce these aniline dyes in three basic solubilities: water, alcohol (spirit), and oil.
Water solubility is our choice. Besides being non-flammable, these dyes are best for "permanency" and light fastness. There is no worry about fire when heated, and you can "deep dye" thicker wood over longer periods.
Alcohol (spirit) solubility is not a good choice for dyeing wood through-and-through. This type dries very rapidly and is best used on the surface of wood for repair work, etc. It is also flammable. Any sanding would remove the color.
Oil solubility is also not a good choice. This type dye is best used on open grained wood such as elm and oak for surface work. It is also flammable, and again, sanding would remove the color.
If you do decide to dye wood, then be sure to consider, among other things, using gloves for skin protection, goggles for eye protection, a respirator for lung protection from dyeing powders and fumes, work in a well-ventilated area, and use an apron to protect clothing from splashes. The book "Step By Step Inlay Banding Production," ISBN:0963238736, now out-of-print, provided more details of the dyeing process. This book will be re-published under a new ISBN in PDF format. Watch for it.
Dyeing can be rewarding and will expand your designing capabilities greatly. If you do elect to dye wood, we can't stress enough that you do your homework. Be sure to guard your health and of those around you.
Do it safely!
