Ebonizing Tasi. Blackwood.

[tea lady]

David Mitchell was showing me his teachers pen at the turnfest on Saturday and I was intrigued by the ebonised blackwood bit.

I did some experiments with some blackwoood veneer. I just put a bit in a vinegar bath with a jex pad in it too. (As per instructions.) I didn't wait for it to dissolve the jex or anything, and it doesn't appear to have dissolved any. No rust. Vinegar still clear even. I just stuck it in to see what happens. But blackwood is black already after 24 hours. I have looked at a few other posts about ebonizing and they suggest that you have to wait for iron to dissolve in the vinegar, which I guess I presumed would turn the vinegar brown or black. (as you do.) A post by U-beaut/Neil suggests 50% vinegar and 50% PURE cider vinegar and dissolving rusty nails in it. Does this mix go black? anyone else done this? (At the risk Of raising specter of rather heated discussion that ensued last time. I am very safety consious and wear gloves and stuff.)

[watson]

G'day Tea Lady,
I've got a stash of "liquid nightmare" made of rusty stuff in the vinegar mix, then filtered etc. This is a continuous brew that I make periodically ( does that make sense???)
I find it works really well if the stock is first brushed with hot Tannic Acid......(available from your friendly brew shop). They use it to put in red wine brews, so its not as dangerous as more volatile acids.
I let the tannic acid dry on the stock ( sometimes I hurry it up with a hair dryer) and then apply the Liquid Nightmare hot as well.
Works a treat.

[tea lady]

So is the "liquid nightmare" black in the jar? That is what I'm confused about. This still just looks like vinegar and the blackwood has gone black anyhow.

[Ron Dunn]

Blackwood is quite a beautiful wood in its natural state. It would be (I think) rare to see it stained ... but in what circumstances would you consider ebonising it? ie, what type of woodwork item?

[watson]

So is the "liquid nightmare" black in the jar? That is what I'm confused about. This still just looks like vinegar and the blackwood has gone black anyhow.

No, the liquid nightmare just looks like slightly darker (browner) vinegar . The use of Tannic acid as a mordant makes it work really well.
Its a chemical reaction, so that the chemicals can produce a reaction within the stock, without being coloured themselves
And any grain in the wood will actually show through the ebonised finish.
Heat, about 80ºc, seems to work well for me.

[tea lady]

Blackwood is quite a beautiful wood in its natural state. It would be (I think) rare to see it stained ... but in what circumstances would you consider ebonising it? ie, what type of woodwork item?

I was using it for one of my teapot handles. On such a small item the Blackwood looked a little boring. Also just fascinated with chemical processes. Here is photo of teapot with handle. This one has sassafras handle but have also done other woods. Also want to try stained blue ones and other weird colours.

Thanks Watson. So it just looks clear.Mysterious!:Spookysmiley: My vinegar bath is going dark now, but I think it might be because th tannin from the wood is coming out. Looks like a cup of tea now.

[Ron Dunn]

Thanks for that, Tea Lady ... another thing learned

[prozac]

Fascinating.

What's a mordant please Watson?

How would you create colours tea lady? Would this be something reacting together in the timber as Watson explained with the Tannic acid?

prozac

[astrid]

Hi TL,
dont know about blackwood, but if you dip a bit of steel wool in vinegar then rub the wood down, it turns cedar black in about 15 mins.

The effect will prolly be different with different types of timber.
most should blacken to some degree.

Astrid

[watson]

G'day Prozac,
Loosely speaking, a mordant is a substance that reacts with the dyeing substance, to produce an insoluble substance of a particular colour.
The Liquid Nightmare (dyeing substance) reacts with the tannins (mordant) in the wood to produce an insoluble black dye within the wood. If the wood is low in tannins ( like pine) the tannic acid is added to the wood to act as the mordant.
There is another substance (Ferrous Sulphate) that can be used as the dye with tannic acid as the mordant to ebonise low tannin woods. (The Ferrous Sulphate is a fairly benign stuff used until recently to raise iron levels in the blood of menopausal women).....it does give a greenish tinge to the ebonising though.
Bugger, too much info.

[watson]

Tea Lady,
Just a heads up that the forum sponsor (ubeaut) has available a set of non-toxic water based dyes that will give you a good range of colours. They also can be diluted/mixed in the normal colour mix ratios....i.e.
blue & yellow make green etc and all the colour permutations you can think of.

[prozac]

Thanks watson. Green/black, sounds interesting.

So does the mordant create the colour or just fix the element that is disolved in the mix? Could you use say copper to give a blue or green hue for instance?

prozac

[watson]

Now I'm not a chemist, but the way I've got it that its the reaction of the mordant with the dyeing substance is what produced the insoluble substance that gives the colour.
I've been playing with common old copper sulphate as a dye with several mordants and as a mordant with other dyes, but all I've ended up with is several shades of brown. I suppose the normal metal type dyeing methods are a bit strong for wood. Fascinating stuff....there's probably a book in using household/garden products to dye wood.

[MacS]

The more "tannin" in the woods, the darker the wood will turn. if there is only a little tannin it may turn yellowish/brown colors.

I'm not familar with a "jex" pad, but if its the same as a "steel wood pad', I would add a few more pads to the vinegar including some old steel nails, allow it to dwell and then stir it up, and then test it on the same wood you will be working on, if its the right color, then strain it in a clean jar, if the color is too light, then let it steep in the vinegar a while longer, if its to dark you can add some water or more vinegar.

Most "teas" contain tannin, you can brew your own, apply it to the wood for color, and then apply the ebony stain that you made up this should make the wood some what darker.

Mac S

[astrid]

What is the difference in result, if you leave a steel wool pad and nails in vineger then apply the solution,
or just dipping the pad in vineger and rubbing it on?

the first just sounds messier?

Astrid