Ebonizing

Overview

Ebonizing blackens wood so it resembles ebony. The chemical method makes an iron acetate solution by dissolving steel wool in white vinegar; the iron reacts with tannins in the wood and darkens it. Where the wood lacks tannin you add it first. Quick alternatives use India ink or black dye.

Pros

• Cheap ingredients and the grain stays visible.
• Dilute solution on tannin-light woods gives greys, blues and purples (Fine Woodworking).
• Quick alternatives exist: India ink (Wood Magazine) or black hair dye (Fine Woodworking, 2022).

Cons

• Colour depends on tannin content, so results vary by species.
• Raw wood goes navy blue; Fine Woodworking says an oil finish turns it black, and that oil topcoats turn diluted greys, blues and purples muddy or green. Use a water-based finish for those.
• The solution is water-based, so raise the grain and sand before, not after.
• Judge only after finishing. Fine Woodworking (Jewitt) says to judge a chemical stain only after it is finished.

Suitability

Reliable on tannin-rich woods such as White oak and Red oak and also Black cherry. On low-tannin woods add a tannic acid solution first; Wood Magazine gives 1 teaspoon per cup of warm water, Popular Woodworking gives 1 heaping tablespoon per pint of hot water. India ink is used on maple (Wood Magazine), with end grain sanded to 320. Black hair dye on maple sanded to 600 is a published alternative: leave 20+ minutes, wipe, seal with spray shellac (Fine Woodworking).

Coats and application

1. Make the iron solution. Wood Magazine: steel wool in white vinegar for about a week, uncapped because hydrogen is released; strain. Fine Woodworking (Robbins): 12 pads of No. 1 steel wool in 1 gallon of vinegar; rinse oil off the pads with lacquer thinner; brew 24 to 36 hours; strain.
2. Raise the grain first; add 1 to 2 drops of dish soap per 8 oz to help wetting (Robbins). Popular Woodworking: raise the grain 2 to 3 times, sand 280 to 320.
3. Popular Woodworking sequence: tannic acid, then iron solution, then tannic acid again. Do not pour used solution back into the jar.
4. Brush on wet; when dry, sand lightly with 400 (Robbins).
5. Black tea pre-treatment deepens it (Robbins). Fine Woodworking (Jewitt) used a water black dye base plus an oil black pigment stain on oak where a more reliable black was wanted.
6. Seal and topcoat.

Compatibility

Seal with shellac then a clear coat (Shellac, Dewaxed shellac). Use waterborne finishes (Water-based lacquer) over greys and blues. Amber tint counteracts purple or green casts (Jewitt). See also Ammonia fuming and Lye and chemical staining.

Care and repair

Scratches reveal pale wood; touch up with fresh solution on the bare patch, then reseal.

Safety and environment

Vinegar plus steel wool releases hydrogen; do not seal the container tightly. Wear gloves and eye protection.

Related

• Ammonia fuming
• Lye and chemical staining
• Water-soluble dye stain