Ferrous Sulfate: (Copperas, Green Vitriol): The standard iron mordant. A high tannin content in the wood (whether present naturally or artificially) and ferrous sulfate yields a grey to steel-blue color. Two oz to a pint of water. POISONOUS, Highly Toxic - Handle with Care!
Some chemicals can be used independently to obtain color on wood, and some are used in combination with natural dyes to obtain color. When used alone, they cause a chemical reaction to occur in the wood itself to cause a color alteration in the wood. When applied additionally with a natural dye, a deeper or even different color may result. An example is Potassium Dichromate. Used by itself on Hondorus Mahogany may result in one color (which can be altered by varying the concentrations), but when combined in use with a solution of Logwood Extract, a natural dye, a different color can be obtained, also light fast. Both are appropriate for certain applications. When these chemicals are used in combination with natural dyes, they are termed mordants, meaning, to bite. A mordant is defined as a substance used in dyeing to fix the coloring matter. Common mordants are basic mordants, such as salts of iron, tin, aluminum, chrome, and combine with basic dyes. Tannic Acid is an acid mordant when it combines with basic dyes. Alizarin, an acid dye will mordant with an aluminum salt to produce bright reds. Some natural dyes are from plants and animals, such as Indigo, Cochineal, Madder Root, Walnuts, and some may be mineral in origin which tend to be more light fast.
Please remember that many of these products are dangerous, some especially so. Follow basic safety precautions when using these products. Use of Gloves and Masks is highly recommended. Request MSDS information if needed. Many of these products have some degree of danger in their use, some extremely so, despite that they are natural. Please be careful. Some products listed here are for use only by the professional finisher.
Olde Mill can not assume liability for the use or misuse of these chemicals and dyes. The purchase of these products by a customer implies foreknowledge of their proper use.