ebonising oak

[marcros]

i put some rusty metal into the remnants of a pickled girkin jar for a couple of days, and last night dipped an offcut of oak in i. Pretty quickly, it turned jet black as I expected it to.

Is there any way of varying this, so that bare oak goes blacker, without going all the way to jet black, or is it a matter of full reaction/no reaction.

One thing that I didnt try was painting it onto a piece with a medullary ray on- would the ray still show through?

 

[Steve Maskery]

The trad way is to fume it with ammonia. You can get .880 ammonia from your local frimdly chemist, although he will probably want to know what you want it for and that you know how to handle it. If you don't, best avoided. It will burn you. The whiff will knock you over, too.
Anyway, you need an enclosure big enough for the piece. This can be a cardboard box or the garden shed. Put both the open bottle of NH3 and the piece into the sealed enclosure and wait. A day, a week, it depends how dark you want it. If you put in a series of scraps as well, you can take them out, label them as to how long they have been in there, so next time you will have an idea of how long you need for any given depth of colour.
English oak fumes the best, AWO doesn't have so much tannin in it.
S

 

[marcros]

Thanks Steve. I had a look at google images, and had wondered how that aged colouring was produced.

 

[Sgian Dubh]

The trad way is to fume it with ammonia.

Actually Steve, fuming oak with ammonia doesn't really ebonise the wood because fuming causes the wood to go brown rather than black. I suspect this difference in the end result just slipped your mind. marcros was asking about ebonising, so I hope you don't mind if I jump in with some alternative information.

The vinegar and iron solution for ebonising does work, although I've always found it a bit hit and miss so I tend to avaoid it. There are other methods I prefer for the job, such as using a black dye, either spirit based or water based, or the use of green copperas, ie, Ferrous Sulphate as described at the following link. The link talks about a couple of grain filling techniques as well as creating an ebonised background colour to the wood prior to the grain filling jobs. Slainte.
http://www.richardjonesfurniture.com/Ar ... table.html

 

[Steve Maskery]

You are quite right, Richard. I was thinking of how dark oak goes in stables, which is years of fuming, but, as you say, it's not actually the same as proper ebonising.
S

 

[Hudson Carpentry]

The water from a wetstone works :evil: I was sharpening a wide chisel last week and as I moved the chisel off the wetstone grinder soem water splashed on a butchers block I had just finished sanding. Even though I wiped up the water within 5 mins where the drips fell was black #-o Thankfully they sanded out!

 

[AndyT]

You could also try Van Dyck crystals for a traditional brown stain for oak. Dissolve them in hot water. Experiment with different concentrations - you should be able to get a range of tones from mid-brown to near black.

Axminster sell them. http://www.axminster.co.uk/liberon-liberon-van-dyck-crystals-prod21990/

 

[Sgian Dubh]

I was thinking of how dark oak goes in stables, which is years of fuming. S

Steve, I suspect, and just guessing really, that some of the darkness seen in oak beams in such places as cowsheds and stables is caused by dirt from things like bedding, dung, and feedstuffs. I'm thinking of decades of dust and the like that floats about in the air; it's got to settle somewhere. Slainte.

 

[chunkolini]

I use ammonium chloride a lot to speed rust steel on sculpture projects, eg 6 hours to an even finish.
Does ammonium chloride do anything to oak?
I will try some on oak and see what it does. I have heard some where about it being use to treat timber but cant remember where.
Google is your friend http://hackaday.com/2011/05/16/chemical-wood-burning/ not exactly relevant but worth investigating.
Hmm chemical woodburning, looks like a new game stencils etc.
I will have a tinker about over the next few days and report back.
I'm sure I have heard of it being used to age timber somewhere along the way, to get that silvery look.