Ebonizing Wood

Ingredients for ebonizing are all household items:

• – Tea
• – Steel wool
• – Vinegar

The reaction with tannins is caused by iron acetate being brushed on the wood. Don’t run off to the hardware store looking for it. It’s simple to make.

Start by washing the steel wool with soap and water to remove any oils. If you don’t do this the oil may prevent a reaction with the vinegar. With the steel wool in a glass jar, pour vinegar over it. You’ll know it’s working when bubbles are coming off the steel wool. Bubbles should start to form within minutes of the vinegar contacting the steel wool. You can cap the jar, but cap it loosely. The gas must be allowed to escape.

The steel wool and vinegar need some time to react; a couple days would be good, a week would be better. If you suddenly realize you need iron acetate for a project NOW, you can accelerate the reaction process by heating the mix in a double boiler. Gently heat the mix for a couple hours, then let it sit overnight. You should be able to use it the next day.

I bought the hot plate for my shop at a thrift store. It’s earned its keep a number of times.

In addition to making iron acetate, make yourself a nice pot of tea. Steep 10 tea bags in a quart of hot water to make a really strong brew. The tea will be used to add tannins to wood.

A good jar of iron acetate will look pretty icky.

Remove particles from the iron acetate by pouring it through a coffee filter.

Brush the iron acetate on to some sample boards and see what you get. Results are not instantaneous. Elapsed time on these boards is two minutes. The tannin-heavy woods-walnut, oak, cherry-are much darker than the other woods.

Want things to get even darker? Add tea. Brush tea on to the wood and let it dry a little. I find results are best if the tea is slightly damp to the touch when brushing iron acetate over it.

The tea really helps. The top board is birch with tea and iron acetate on the right, iron acetate only on the left. The bottom board is walnut, raw on the left and iron acetate only on the right. The center board is walnut with tea under the iron acetate. It’s significantly darker and more opaque then the other walnut board.

You can also brush tea on top of the iron acetate. The bottom line is that tea has a lot of tannins in it, so it’s a tannin-additive for low tannin woods.

Ebonizing only affects the surface so machining, such as routed profiles, should be done before ebonizing.

The ebonizing process may raise the grain, especially if you use tea. It’s a good idea to do a pre-ebonizing grain raise. Brush on a little water and, after the wood dries, sand off the whiskers. That should prevent you from having to sand the ebonized piece and taking the risk of sanding off the ebonizing.

The iron acetate needs to get into the wood, so don’t sand finer than 220-grit or you may prevent the liquid from soaking in and having the chance to react.

Give yourself ample opportunity to experiment with this process before using it on a project. Keep the test boards and record how you made them.