Ebonizing Wood

Woodworking Techniques for Ebonizing WoodThe next time you’re working on a project that calls for a dark, opaque accent, a piece that looks like ebony, try ebonizing wood for just the right look. It’s a fairly simple process, but works better on some woods than others. This story will give you what you need to know to ebonize wood in your shop.

Ebonizing wood is not the same thing as simply coloring wood with ebony stain. When you ebonize wood you’re causing a chemical reaction that makes the material turn black. The benefit to this process is opacity. When wood is stained you can sometimes see the grain through the stain. When wood is correctly ebonized it becomes pitch black, and you won’t be able to see grain through the color.

It’s important to understand that this is more art than science. You should definitely experiment before using this technique on a project.

Suitable Woods. Ebonizing depends on the wood having a lot of tannin content. As a rule hardwoods have more tannins than softwoods, and dark hardwoods more than light hardwoods. That makes oak, cherry and walnut good candidates for ebonizing. Birch and maple are not good candidates, but I’ll show you a way to work around their shortage of tannins.

Even among the usual suspects there’s tannin and there’s tannin. One piece of walnut may ebonize completely differently than another. You’ll need to experiment with the pieces you’re using to see what it takes to get the results you want.

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Woodworking Techniques for Ebonizing WoodWhat You Need. Ingredients for ebonizing are all household items. Tea, steel wool, and vinegar.

Woodworking Techniques for Ebonizing WoodEbonizing Requires Iron Acetate. 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.

Woodworking Techniques for Ebonizing WoodThe 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.

Woodworking Techniques for Ebonizing WoodI 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.

Woodworking Techniques for Ebonizing WoodRemove particles from the iron acetate by pouring it through a coffee filter.

Woodworking Techniques for Ebonizing WoodDo Some Testing. 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.

Woodworking Techniques for Ebonizing WoodWant 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.

Woodworking Techniques for Ebonizing WoodThe 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.

A Few Notes.

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.

Photos By Author

Click here to watch a related Ebonizing Wood video clip.

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28 Responses to “Ebonizing Wood”
  1. Woodwright

    I have a cut off plastic milk jug that I filled with several pounds of common nails, no cement coated or galvanized, just common box and finishing nails. Soaked it well with
    a 50/50 mix of apple cider vinegar and water and let it sit. Strain off the liquid and use for ebonizing. I’ve been using this same jug of nails for more years than I care to admit. Whenever I need a fresh solution I just add more water and vinegar and within an hour or so have more when ever I need. The black tea trick mentioned above is a great tip also for increasing tannin content to lower tannin woods.

    I’ve used this technique in various forms from complete black ebonizing through sanded afterwards to offer more contrast. Another technique is to back fill open grain woods like oak, ash, hickory with a contrasting color. For this I’ve used a wet lime paste (think plaster of paris) as well as latex paints. This is a variation on pickled wood techniques from a bygone era. Apply a dilute latex paint, (use the appropriate solution for the type of paint being used) I most often dilute latex with regular paint thinner. I part thinner to 3 parts paint. Apply this and wipe down surface with a clean, thinner dampened cloth to remove excess paint from the surface. You just want to back fill the open grain. Apply several times to really fill in the grain. You can hit the surface lightly with a bit of thinner on a green scotchbrite type scrubbie. Allow to dry between coats. If your ebonizing is not as dark as you would like after this just reapply your ebonizing/ black tea solution to bring it back. This will add some working time to any project but the results are worth the effort.

    • ezgoing

      Interesting article and very interesting comment from Mr. Woodright… Thanks!!

      Is one particular type of tea better than another?

      I just so happen to have a can or two of un-coated nails that have rusted (I think we ALL have one of those) LOL. Being the cheap-skate that I am, I didn’t want to toss em, but wasn’t sure just what I was going to do with them… NOW I know…

      I was thinking of routing a shallow groove around drawer fronts, or maybe using this process on routed signs, then sanding off the treatment on the upper flat surface…. Almost instant highlighting with a little bit of extra sanding to do… OH the possibilities – Thanks again!

    • WWGOA Team

      Hi, Alex!

      You can use whatever topcoat you would like following ebonizing. I’d suggest waiting 24 hours prior to applying topcoat to allow for full drying and as well as to allow for any chemical reactions to fully stabilize.

  2. Steve Dixon

    Could you make dark plugs for holes and decoration in Mission style furniture? Will the Black wood take glue?

    • WWGOA Team

      Glue adhesion would be fine for this application, but the ebonizing process does not go very deeply into the wood, so when you sand the plug flush it would remove the dark coloration. I suggest getting some black walnut for this purpose instead.

      • steve

        for smaller pieces of wood like door knobs and dowel etc. can you let them soak into the ebonize color say for a week therefore penetrating the wood deep would this allow sanding afterward and not sane the think layer of ebonize color off since it deep within the wood.

        • WWGOA Team

          You can try it, but my hunch is that you will still not see color penetration go super deep into the wood. As a chemical reactioin process, my guess is that you will need air as a catalyst to facilitate the reaction. But if you try it, please send us a cross-section picture of the test pieceto indicate the depth of penetration. (ZD: 3533)

  3. Lee

    I want to create a gray weathered look on resawn skip sanded douglas fir flooring. I was told that the floor may change color possibly at some future time. Any experience with that?

    • WWGOA Team

      I have not seen the effect that you are describing, but it is possible that as wood ages, the ebonized edge might patina differently than the rest of the plank, causing a difference in appearance. My guess is that, if it did happen, the process would occur slowly over the years

    • WWGOA Team

      The process that they are describing is probably using ammonia to “fume” the wood, which causes a chemical reaction and creates a dark color in oak. If general, ammonia is an extremely toxic substance, so if that is what they are doing, then I’d be concerned. But they might be using some other approach this is food safe. I’d suggest asking them directly what process they are using, and what science they are basing their claim of “food safe” on.

      • Kelly Zaneto

        i’ve replied a few times to ensure there is no misrepresentation of our products & finishes on this thread. the process we use in NOT toxic. we do NOT fume. i’d be happy to answer anyone’s questions about our processes. you can email us directly.

  4. Stephen Priesthoff

    Back to what Cindy was asking about this particular process, ebonizing (oak in particular) wood with iron acetate. Is this food safe? I make wooden flutes and would like the ebony look, of course people put their mouths in direct contact with my instruments so I have to be careful.

  5. Kj pipes

    I work with fairly dense burl wood with beautiful grain. In my profession the higher contrast you can achieve with the grain the more valuable. To achieve the contrast I apply a dark stain then gently sand it off leaving the dark grain a dark color and the lighter wood light. Then I apply a lighter top coat that colors the light wood. And bam cotrast achieved. The problem though is there is a lot of color blending when the top coat is applied not achieving the high contrast I would like. That being said does this stain method mentioned in your article chemically alter the grain in a way that if I where to implement my contrast method ie lightly sanding the wood, the grain would be chemically stained there,fore not mixing with my top coat?

    • Customer Service

      Hi. Your process sounds very cool. I’ve done the first step that you describe on figured maple with transtint dye and achieved very good results. I haven’t taken the next step and added additional coloration, but I can see where that might be problematic. I haven’t tried applying a non-clear topcoat on wood that has been “ebonized” using this process, so I don’t know for sure. My hunch is that it would tend to blend less than traditional stain, and it is worth a try on some scrap. I would also suggest trying transtint dye. Depending on the species that you are using, and the size of your project, you might want to try ammonia fuming as well. That should not give you any problem with blending colors. It might also bring out some of the figure better in the burl better than stain. Maybe. If you haven’t done fuming before, the process is described in Seth Keller’s article here: https://www.wwgoa.com/article/an-authentic-arts-and-crafts-finish/. I’ve had great luck using the janitorial strength ammonia from Ace Hardware. Be careful with that stuff.

      Please let us know what you find if you explore any of these options. I’d love to see some pics of your projects as well.

  6. Nikole

    Hi. I have been experimenting with the steel wool/vinegar reaction to woods. I love what it does on oak but before I discovered it I bought raw hickory flooring straight from the mill. I am doing the ‘add tannins w/ tea’ in experiments. I get a gray color that I love. HOWEVER, I would like to figure out how to get contrasting grain a little darker and I’m confused about which part is more pourous and how it reacts to the tannins. Is there anything other than tea that would give me more tannins so that I could come closer to the ebonizing that happens with oak?

    • Customer Service

      Hi, Nikole. Good question. Unfortunately, I’m not aware of anything, but if you come across something, please let us know.

      • willie pete the pete miester

        Quebracho(axe-breaker) tree bark powder is very high in tannins. Leather tanners/taxidermy places carry it sometimes

  7. Valerie

    This was really helpful information. One question: My old turned wood oak table has a finish on it. How can I best remove the finish without adversely affecting the ebonizing process? Can I send it to be vat-stripped? Thank you for your help.

    • Customer Service

      Hi, Valerie. I do not know how the stripping process will affect the ebonized look of the wood. I would suggest trying this on scrap before working on your actual table.

  8. marcosc1218

    I have read that you can also get wood to change to a dark color by heating it in a oven, do you know anything about this.

  9. Danielle

    We have been ebonizing all sorts of wood with great results. However, I have run into issues where sometimes there are spots that won’t take the color at all- whether it is sappy or what, I don’t know. Some of this might be in a crack (we do a lot of live edge work and not everything gets resined) or, with elm, I have found that the more open grain does not always take the color. Any ideas for how to blacked the areas in the crevices? Or have you experienced this before? I was tempted to just take a very tiny brush and apply a dye as it is not directly next to the flat surfaces that did take the stain, but was curious to hear if there were other ideas.

    • Danielle

      I also should add that we use a quebracho tea to add tanins to woods that do not typically darken enough…but there are still areas that just don’t change color at all.

    • Customer Service

      This is a fairly uncontrolled way to color wood, and so far I’ve only done this with an attitude of “I get what I get when the process is complete”. I haven’t experimented with how to even up and appearance. I suspect that you could do this somewhat with experimenting with adding tannin, or using dye or stain, but at that point I believe that I would forego the ebonization process entirely and start with a good quality dye product such as Transtint. With Transtint, if you get any unevenness in penetration or coverage, you can even it up by adding some additional dye to your topcoat, which can knock down some of the color discrepancy.