Ebonising Karri

[DaveVman]

I have only stained about 2 things. I used commercial stains. One was the colour the client wanted and not my taste so I didn't like it anyway. The other came out OK.
So that's a long way is saying I don't have much experience or confidence with staining.

I want to make a stand for a marble table top. I have some Karri for the job. I will probably just shellac the Karri. However it has occurred to me that an almost black wood might contrast with the top better.

I saw a video of wood soaked a mixture of vinegar and rusted steel wool to ebonise the wood. He said if the timber is low on tannins then first soak in old tea.

Two questions:
Does Karri have plenty of tannin in it to be able to ebonise this way?

Soaking is not practical so is the technique to brush on liberaly as many coats as required until the desired darkness is achieved?

Does this soak into Karri enough?

I know I should just do some experiments but I lack confidence with it. Perhaps this isn't the right project to learn on.

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[Robson Valley]

I've done this to wood carvings.
One "bun" of fine steel wool in maybe 1,000 ml vinegar.
Takes a few weeks to totally dissolve.

Test it on scrap first. Birch (Betula papyrifera) heart wood has fair tannin.
All I got was a dirty dull gray color.
No. many coats isn't darker, all the reaction chemistry got used up.

Yes, you can paint the wood with very strong tea for extra tannin and let that dry first.
Then stain.
I have not tried that.

Historically, lots of furniture and wood work was built with various species of oak (Quercus) here in North America.
We have a rotten selection of wood colors. Most is really blah pale when compared wit the woods of OZ.
Be grateful for what you people got.

Anyway, the iron acetate stain and the ancient(?) ammonia fuming were efforts to add some novelty to our drab woods.
The oaks happened to have lots and lots of tannin so these tricks work very well.

For very dark with lots of wood tannin, try ammonia fuming.
Out doors, a soup dish in a garbage bag, fill the dish 1/2 full of ammonia bleach.
Chlorine bleach does not work.
Add the wood and close up the bag for 24 hrs.

[dai sensei]

My ebonising mix is steel wool/vinegar/old tea bag, leave for a few days or preferably a week, then strain through some paper towel. Paint on a soaking coat and leave to dry, if not black enough, apply another coat etc. Will turn most timbers, especially eucalypts black as, whilst retaining grain

[Skew ChiDAMN!!]

I'm no expert but I believe that Karri is pretty high in the tannin rankings... and it's tannin leeching that causes the problems people have with it staining near-by materials. Of course, I could be wrong.

Obviously, the answer is to try test samples. RV's advice above is good.

When it comes to adding tannins with tea, I fill a glass jar with pot strength tea bags, barely cover them with hot water and let them stand for a few days. Easily done while you're waiting for the steel wool to break down. I use the tea bags as applicators, simply wiping everything down with them. It saves on clean up. ;)

Let us know how it goes for you!

[DaveVman]

Thanks guys.
Yes we are so lucky in Australia with the multiple timbers available. I'm just learning about them.

This was in fact why I went with Karri. I wanted a rich timber colour for some lamps so I got some extra for the coffee table. It just now that it occurred to me to consider a blacker timber.

If I do this and then finish with shellac will that create a stain proof barrier?
It has to go on a creamy white carpet below and a white stone top above.

I have shellac and oil based polyurethane in the shed or I could use something else.

or in this case is it best to stick the the natural colour of the wood and shellac?


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[DaveVman]

P.S. one web site I read said the Karri has "Poor reputation to holding paint and impregnation of preservatives".
What might that mean for the creamy white carpet?

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[Skew ChiDAMN!!]

If I do this and then finish with shellac will that create a stain proof barrier?
It has to go on a creamy white carpet below and a white stone top above.

I have shellac and oil based polyurethane in the shed or I could use something else.

or in this case is it best to stick the the natural colour of the wood and shellac?

No matter what you finish it with, I wouldn't consider it a "stain proof barrier."

With white carpet, it's not the ebonising I'd worry about, it's the Karri itself. Most of the time it's OK, but every now 'n again you'll get a piece that can exude a dark stain. A bit like Merbau. The stone top should be fine.

Personally I'd quite happily use Shellac to finish, ebonised or otherwise, then go buy some of those little plastic carpet protecting cups that fit under furniture legs. I imagine you know the things... a bit like sitting your sofa in saucers!? :D

These have a couple of advantages. Firstly, it spreads the weight of the item over a larger footprint, reducing the "dings" you get in carpet from heavy furniture. Secondly, it can take several weeks for your finish (whatever it may be) to fully harden. Using these will prevent fine carpet fibres from sticking to the bottom of the feet so the item can be put into use earlier, instead of sitting in the shed for a fortnight or more.

Lastly, but most importantly in this case, it'll give you time to observe whether or not you'll have a problem with leeching and protect your carpet in the meantime.

If, after six months, all seems good you can remove them. Or not.

Don't forget that we like pics! ;)


P.S. one web site I read said the Karri has "Poor reputation to holding paint and impregnation of preservatives".
What might that mean for the creamy white carpet?

It has that rep because it's an oilier wood than most people are used to. With such timbers it's best to give 'em wipe down using a rag dampened with metho to remove surface oils immediately before applying a finish, giving the finish a chance to adhere/penetrate to the timber and not an oily surface film.

Do this after ebonising - if you go that way - as those oils contain the very tannin you're trying to convert.

[Skew ChiDAMN!!]

I meant to add that you should NOT count on ebonising to make the timber black; I use the process to age new timbers to match the old in heritage restos.

Some timbers will go black, others don't and just darken. Worse, some tannin rich timbers will darken blotchily.

I heartily recommend doing a test piece to see if you like the look!

(I'll shut up now... )

[dai sensei]

I meant to add that you should NOT count on ebonising to make the timber black; I use the process to age new timbers to match the old in heritage restos.

Some timbers will go black, others don't and just darken. Worse, some tannin rich timbers will darken blotchily....

If the timber has uneven amounts of tannin, or a tannin soak doesn't soak in evenly, it can end up blotchy. By putting in the tea bag in my ebonising mix, then applying the mix liberally (ponding layer) and let dry, I've had much better results. I must admit to only doing eucalypts or acacias but have never had an issue since.

[hurcorh]

There are 'ebony' stains out there that might product an 'ok' finish. Gel/oil stains/coatings from Osmo or Rubio might be alternatives, too. A few small sample packs might be enough for a small job.

Alternatively if you want to use the ebonising mixture as described above, you can look at doing a pre treatment coat. There are a few off the shelf ones but you can also make them. I've tested a few home made recipe's and found one I like to make. It works well to remove any 'blotchyness' that might occur. You just do a soak coat and allow to dry for a day or so. Then do the normal ebonising mixture. The following crude picture shows the regular single coat on the left hand side vs two on the right with different pre treatments. This was a single coat application of pre treatment and single coat of ebonising on american white oak.
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[clear out]

If the timber will take a shellac finish ok and you want black you could add carbon black to shellac.
This chair was done over 30 years ago.
Timber is NSW Rosewood which can be a bleeder.
H.

[DaveVman]

If the timber will take a shellac finish ok and you want black you could add carbon black to shellac.
This chair was done over 30 years ago.
Timber is NSW Rosewood which can be a bleeder.
H.

This sounds easier. I am confused by the pictures. One shows a very black chair. The other is prior or during restoration?Or after 30 years?

How do I "add carbon black to shellac"?

http://www.jugheads.co/shop/wp-content/uploads/2012/10/BLACKJACK1.jpg

[clear out]

The photos were both taken same day I posted,one in shade the other detail in full sun.
Having done this a few years ago took me a while to chase up info on this process.
If any restorers/conservators want to add info that’s welcome as I’m getting vague:C

I used Aniline dye powder bought from an art shop.
Brushed it on and used a fad to produce a French polish finish.

Pretty sure this was the same as I used as an apprentice Patternmaker for coating the patterns. The colours were for different metals or parts of the pattern.
Black for Iron with Red for machining and Yellow for prints.
Non ferrous Yellow with Black prints.
You just make up your shellac as normal with flakes andDNA or metho and add the powder to the matured shellac. As an apprentice I mixed up the dog dick red and baby s yellow.
Cant remember what those base powers were, it was 55 years ago:doh:

A few pics of my old Aniline dye and some Iron Oxide I scored recently on clearing out a deceased restorers shop. Might try some and see how it works.

Also a pic of an old style pattern they paint them now in 2 pack or undy depending on the type of material they will be moulded in.

Best thing is buy some dye and have a play.
H.

[Bushmiller]

The technique of "ebonising" particularly interests me and I would very much like to try it next time I require a timber to be blackened. I would like to have known more about it when I did this project more than ten years ago. Gerrit Rietveld's Red Blue chair was painted red, blue and yellow, but the "structural components were stained black. So in my two versions to achieve this I used Feast Watson Prooftint, in black of course.

438851438852438853438854

From a distance the timber appears completely black, but up close it is not so black at all. However, I think I used only a single coat of stain (maybe two as I can't really remember now). I definitely could have increased the "blackness" with more coats. Difficult to capture the exact colour. What looks white in the pic is in fact a strong lemon colour. (Incidentally, always try to avoid yellow if you can: For anything :) ). The grain of the timber is very visible through the stain so it would have definitely taken more coats and as it is, it does appear a little blotchy. Funny thing is I don't notice this until I get up close: A bit like getting old :rolleyes: .

438855

The timber is Ironbark so not an easy one to treat. It always did have the stress cracks in the timber. It may be worth experimenting with a product like this first.

Regards
Paul