Ebonizing

[JNCarr]

Just finished designing a free-standing bar-height kitchen island. Open frame with a shelf.
Am contemplating ebonizing the frame and using either cherry or rainforest granite for the top.
I can make the frame out of any of the high tannin woods.

I've read the FWW and other articles on ebonizing - does anyone have actual experience in doing it and have any tricks or gotchas to offer up?

 

[cyclopentadiene]

I have done this applying Tannic acid (available from beer and wine making suppliers) to ash. In a jar, I mixed steel wool, some iron nails and vinegar and let it stand until the steel wood dissolved. After filtering, the orange liquid is brushed onto the wood and it instantly goes black. Maple, pine….and other white woods lack tannins and need a tannic acid wash to ebonize
The ash had a very bluish tint which I was not happy with but it is the vase of my shop workbench so who cares. I would not be happy with whitewood furniture that is ebonized this way. The blue undertones take away from it.
Walnut, sapele mahogany and cherry will also do very well without tannic acid as these woods have a naturally high tannin concentration. However the “blackness” is darker with added tannic acid.

 

[Wiley's Woodworks]

I have made several pieces using ebonizing as a finish. I like it; it's easy to do; it's the best way IMO to get a great color contrast with light colored woods. My best results have come with white oak; it's the highest in tannic acid as far as I know. I have used it on glued up laminations, and the glue lines disappear.

Start with Heinz white vinegar (I picked up this tip along the way) and a #4000 steel wool pad. Wash the pad with dish soap to remove any oils from the manufacturing process. Drop it in a pint of vinegar and let it sit until the pad is dissolved. I don't see the harm of throwing in a few iron nails, but I don't know the consequences if any additional iron is rusty. Next, mix up a coffee mug of super strong tea--too strong to drink. I use one tea bag for every 2 ounces of water. The tea is high in tannic acids all by itself; it will multiply the chemical reaction between tannins and the vinegar/iron solution.

The application sequence is variable:

• Apply just the vinegar to the wood and see if it turns dark enough to satisfy you.
• If if doesn't then brush on the tea. This can be repeated if you like the progress. I never needed to but you could apply a second coat of vinegar
• Or, saturate the wood with the tea as your first coat. Make sure it is completely dry, then
• Apply the vinegar.
• A coat of tea on top of the vinegar is optional.
• Additional coats of vinegar are optional, but the additional darkening is minimal.

My preference is to put on the tea, then saturate with the vinegar. This puts more tannins on the surface where the chemical reaction occurs. When you are ebonizing you really can't get it too dark. Regardless of which process you choose, really slather on all coats. The solutions need to penetrate into the wood. I use a throw-away brush and keep applying it until the entire piece is shiny wet at the same time. Let each coat dry thoroughly. Check the piece by feel for any fiber raising caused by the liquids. If you feel any lightly sand with 400 grit. You won't sand through to white wood. Any kind of topcoat finish can be applied to the entire piece.

The photos are an ambrosia maple box with glue lam white oak legs with wipe on poly final finish.

 

[Dee2]

Joe,
I've tried ebonizing but have moved to India ink for less hassle. You can mix it with about anything as far as I know, e.g., I use the stuff in epoxy and titebond when I want black glue. A little goes a long way. As always, YMMV.

 

[JNCarr]

Thanks all - this helps point me in the right direction for a few experiments, including India ink. Much appreciated.

 

[tvrgeek]

Me too.

 

[JohnnyR]

Joe, rain forest (which I love and had in my previous house) is a marble, not granite, -as I was told- so good care is more important.

 

[JNCarr]

Johnny - thanks for the heads up on that! Interestingly, if you google rainforest marble or granite, you get pretty much the same pictures.
I'll definitely probe into this with a reputable local dealer. Thanks again.

 

[JNCarr]

For those interested here are the results of the ebonizing tests I ran.

Materials

• Red oak stock sanded to 220
• Iron Acetate solution -
  • 1 wad of 0000 steel wool triple washed with Dawn detergent
  • 3 cups commercial (6% acidity) vinegar heated to about 160F
  • Removed from heat and left with loose cover to sit for 4 days - no straining needed, it was all dissolved
• Tea - ~8x strength black tea
• India Ink - Speedball super black
  • Straight or diluted 1:2 with dewaxed shellac per test

Application-

• A - 2 coats tea, light sand 220, iron acetate, light sand 320, 3rd coat of tea
• B - 1 coat tea, light sand 220, iron acetate, light sand 320
• C - 2 tea, sand, 2 iron acetate
• D - no tea, 2 iron acetate, sand 320
• E - no tea 2 iron acetate, sand 320, 1:2 diluted ink
• F - Straight ink, light sand 320, ink
• G - 2 coats Minwax Ebony
• H - 3 coats Minwax Ebony
• I - 2 tea, iron, sand 320, diluted ink
• J - ink, sand 320, ink
• K - diluted ink, sanded 320, diluted ink

Results
The Tea/iron acetate solutions did in fact react well to darken the wood. Without the tea pretreatment, the result on oak is a blueish black. With a single tea treatment, you get a Paynes Gray. The more the tea, the darker and more neutral the color becomes. Minwax ebony gives a warm brownish black. It takes three coats to get what would be considered black. India ink gives a neutral black either straight or diluted. The reason I diluted it with shellac was to try to reduce grain raise, since there is (mostly) water in the solution and it raises the grain. The shellac appeared to reduce the raise.

The easiest and most neutral is the ink diluted 1:2. Although there was some grain raise, it was easily knocked down and the subsequent ink coat did not raise the grain hardly at all - quick go-over with drywall tape finished it off nicely. I tested shellac and diluted poly over all the stains and all took them well. As expected, because some of the binder in the ink is shellac, there was a little bleed back on the rag. It did not lighten the color. With all the coatings, the grain shows up nicely.

 

[Stuart Kent]

I've been ebonizing wood for a long time. Using the washes mentioned above are reliable, I too do not like the blue that commonly occurs from white woods. In my opinion, white oaks (white oak, post oak, etc...) require no additional steps. Dissolve steel wool in white vinegar in an open (no lid) glass container for about a week. Strain off the solids through a paint filter of coffee filter. Brush the Iron Acetate directly onto wood fully prepared for finish. Oak turns black.

 

[shawn]

Before and after pics of ebonizing dye on eucalyptus. I just use old nails. I don't like eating wasting a good piece of steel wool. Iron is iron. I don't use anything else. In George Frank's book "Adventures In Wood Finishing" he says pigmented ebonizing stains"castrate" the wood. The iron acetate blackens the wood without masking it's character.
The longer you let the mix sit, the stronger it gets. Multiple applications will darken the wood further.