Ebonising oak

[Harry581010]

I like to stain some of the oak I work with and use acectic acid with iron wool. It'll typically take a couple coats and to get things a bit blacker, instead of a blue/purple hint to it, I add a coat of a tannin product dissolved in water. My question is can I just add the tannin to the acetic acid and wire wool solution? Or would that react for some reason?
Thank you

 

[Orraloon]

You could try a few experiments. I have only tried it the one time and I did not mix the tannin in but brushed it on before doing the acid/iron mix. As the tannin was not dry when the mix was brushed on suggests that the tannin could be mixed in. I just followed the method I had seen in a few on line clips but I think keeping the tannin seperate will give you more control. My mix was just white vinegar and steel wool left in a jar for a week and tea for the tannin. I tried things on a few offcuts before doing the main project.

I found by trial and error how many coats were needed and that the tannin was required.
Regards
John

 

[Cabinetman]

Best to “wash” the s/wool to remove the oils added to prevent it rusting, try washing up liquid.
Good advice above. I have tried to turn Oak black and spent a Lot of hours on it, the best I could get was a lovely shade of Royal Blue. A rub with black shoe polish sorted that out.
After that I gave up and now add a little black dye to water based poly varnish, totally foolproof.

 

[Orraloon]

Yes I should have mentioned the washing of the steel wool. In my case I had already had the steel wool in the jar for about 24 hours before I found out that bit of info so I just carried on without washing. I should think washing would speed up the breakdown of the wool and perhaps prevent the scum that forms on top of the solution.
Regards
John

 

[Yojevol]

Indian ink if you want it really black

 

[kinverkid]

Another here for Indian ink but also consider good quality printer ink refill. Wear gloves because meths, isopropyl or acetone won't get it off,

 

[Fitzroy]

I would say it depends on if the product of the tannin plus iron solution is water soluble or not. If it is not then it would precipitate out when you mix the solutions and it would be hard to apply evenly to the wood. This would be easy to test by making a mix and leaving it to see if the black compound settles out.

I’m also an India ink convert for truly black items.

 

[Harry581010]

Thank you for the ideas I'll give them a go

 

[Orraloon]

It is water soluble so after you get the degree of black you want(more coats=blacker) you can apply any oil coating or oil based varnish you like. I used a marine varnish. I did not want to take a chance on water based products. A chemical reaction between the iron oxide and the oak tannin causes the black colour. Adding more tannin helps things along. There is no black compound to settle out. All this talk of Dye, Ink and other coatings is a different process. I have posted a pic of the result so if anyone wants to post how dye, ink or anything else turns out please feel free.
Regards
John

 

[SimonStevensCanes]

Matt Estlea used a combination of ebonising and Black Rubio Monocoat to get a truly black finish in this video...

 

[Harry581010]

Matt Estlea used a combination of ebonising and Black Rubio Monocoat to get a truly black finish in this video...

It might be this video that got me wondering about the best method. At one point he has a clip of different concentrations and says to click the link but there isn't one! Maybe that vid will be out soon

 

[Inspector]

I used oil free steel wool bought on Amazon and a cleaning vinegar along with wine tannin (made from Chestnut bark I think) also from Amazon but I applied them separately. Dissolved the steel wool and then filtered it. Used hot water to dissolve as much tannin powder as it would take. I put the tannin solution on the oak first and when it dried the steel wool/vinegar. I repeated three or more times over several days. It looked to me as I did it that the wood was darker after the tannin applications so I ended there. It was still a blue black. I used a linseed oil based finish on it and the yellow/amber of the oil made it a nice black. Probably more time consuming than a back ink or stain but it works and is easy enough.

Pete

 

[stuckinthemud]

I think the level of blackness depends on the amount the oak has seasoned and perhaps air dried rather than kiln dried- green oak goes really black. Pre-soaking in strong tea can be a big help, I imagine, in restoring tannins . I ebonised this with rusty nails in vinegar, but other oak I have ebonised didn’t go quite so dark.

 

[SkinnyB]

I like my ebonising and use it a lot for my furniture and boards.

Fine wire wool soaked in cheap white vinegar from Lidl. I usually leave it for a month or so so the wire wool has completely dissolved. No pre-washing the wire wool. I feel like vinegar is used for de-greasing/cleaning anyway.

Wood is always Kiln dried oak no added tannins etc.

Method:
Apply ebonising solution to oak by brush.
Leave to dry.
Sand using 240 grit. Recommend soft backer pad on ROS. (Random orbit sander)
Second coat ebonising solution to oak by brush.
Leave to dry.
Sand using 320 Mirka Mirlon pad on ROS
Vacuum off
White spirt wipe down
Apply oil based finish. Osmo Poly

Will leave a deep rich black with the grain showing though. I think if you add washing up liquid to the ebonising solution it removes the surface tension and soaks better into the deep grain if that is the effect you are after. Not rid it though.

Without Oil it will be matt blue in colour.

https://www.ukworkshop.co.uk/threads/wedding-table-build-with-pictures.142343/

https://www.skinnerdesigns.co.uk/product-page/z-chairs-ebonised-english-oak

Black oak End Grain Chopping Board.

 

[SimonStevensCanes]

I'm curious about the durability of that chopping board, presumably it'll need re-blackening periodically?

 

[SkinnyB]

As the ebonising isn't very deep you are correct in that it can wear away. Being that it has an oil based finish (Osmo top oil) it would also prevent new ebonising solution from soaking in. I haven't yet needed to re-blacken and this is something my clients are told when purchasing this specific board.

If I was going to re-ebonsise I would plane down the board removing the Oil surface and hopefully be able to re-ebonise.