1 vary from lower concentrations in birch and maple to higher concentrations in cherry and red oak. The typical amounts of tannins in the four wood species listed in Fig. A protocol for creating and using an iron acetate ebonizing solution is described and was demonstrated to be a much-improved version of the one currently promoted in the woodworking literature. Maximal darkening of cherry and red oak wood with minimal application of iron solution was attained by applying a 0.125 M iron acetate solution at a rate of 1 mL per 125 cm 2 of wood surface. A volume of 85 mL of distilled white vinegar per gram of super fine (#0000) aged steel wool provided a final reaction mixture with fully dissolved steel and no precipitated products. Both inorganic phosphate and air (O 2) were required for maximal reaction rate. 4H 2O (and H 2) and subsequently basic iron acetate (CH 3COO) by air oxidation, giving a red-colored solution. Products were ferrous acetate Fe(CH 3COO) 2.
Iron acetate is not readily available, so woodworkers prepare it in the woodshop by reacting steel wool and vinegar.
According to the literature, the darkness and color are controlled by the tannin concentration (higher, darker) and the counterion of iron (acetate, darker). Woodworkers darken wood by reacting iron in solution with tannins in the wood to form blue–black phenolate complexes, a process called ebonizing.
