5

I have been collecting old nails from pallets that I have been tearing down and only realized now why I was keeping them. I am going to try and make my own stain.

There are several tutorials online that talk about making an ebonizing or oxidizing stain. Regardless of the name they all involve at a minimum rust and vinegar.

The part I don't completely understand is why one some tutorials say to use regular vinegar and others apple cider vinegar or even balsamic vinegar. This could just be a preference but I want to know the actual difference that using those vinegars.

I do understand the many variables that exist with this type of experimentation but this particular aspect is not really covered in the tutorials I have seen.

Matt
  • 20,188
  • 41
  • 99
  • 202
  • As far as i know, all that matters is creating an iron oxide solution. Plain vinegar works and is cheap. If you're really going for the ebonizing effect, other ingredients should be mostly irrelevant. – keshlam Aug 18 '15 at 02:56
  • 1
    Use whatever type you already have in the cupboard/pantry. If you already have a jug of each, try both and see if you prefer one over the other. – rob Aug 18 '15 at 03:58
  • How would apple cider vinegar or balsamic (which is mostly vinegar plus sugar) or any other super duper vinegar be different? They all contain acetic acid, which is the active chemical that you are using. The cheapest stuff that you can find will do. – Damon Aug 25 '15 at 14:24
  • @Damon After reading all the comments here and understanding the process that is my findings as well. Thanks. – Matt Aug 25 '15 at 14:25

1 Answers1

5

The part I don't completely understand is why one some tutorials say to use regular vinegar and others apple cider vinegar or even balsamic vinegar.

What most guides don't simply spell out in plain English is this process is actually a chemical reaction in which you're making iron acetate.

The iron acetate then reacts with the tannins in the wood, which forms iron tannate, a black metallic salt: hence the very dark colour in some oak (high in tannins) and the slight greying you usually get in softwoods (very low in tannins).

So anyway, the reason to prefer one vinegar over another is simply to do with the acetic acid content. Higher acetic acid level = more iron acetate formed. With a stronger vinegar you get a stronger solution of iron acetate and this give a more pronounced reaction in the wood, and faster.

Regardless of the name they all involve at a minimum rust and vinegar.

In reality you just need iron and vinegar. Rusty metal is no more or less desirable here, as seen by the most common method of forming this 'dye' which uses steel wool.

However there is a bonus if you do use rusty nails, as this will do two things simultaneously: it will clean the rust from your nails as well as forming the iron acetate solution :-)

I should add here that if you're specifically looking to do ebonising this alone is not a reliable way to get there. Wood, even oak, is often not quite high enough in tannins to make a good black colour and it can vary even from piece to piece in the same lot of wood, so you could end up with one grey board within an otherwise black piece.

There are various chemical means to achieve a more reliable black, e.g. by introducing tannic acid to the wood, or with sulphuric acid and a heat gun, but the simplest (and safest!) method is just to paint the wood with Indian ink.

Graphus
  • 65,691
  • 3
  • 50
  • 139
  • My first test was going to be with pine which is very low in tannins. I read that using some teas, like black tea, could help with that. Either way it will be fun to try it out. – Matt Aug 18 '15 at 10:43
  • Yes, tea can be a good source for tannin. And if you're willing to resort to it, even a black marker is sometimes a decent black stain. – keshlam Aug 18 '15 at 14:09
  • @Matt, yes you can introduce tannic acid using tea. I did a test of this about two weeks ago. It's worth doing a stepped test board to check the effect: bare pine then one, two and three coats of tea, after which you paint a line of the iron acetate over all four and see the difference. If you're after a really dark grey or black it's worth buying tannic acid in powder form online, a small bag will last a lifetime. – Graphus Aug 18 '15 at 17:20
  • That stuff is pretty cheap it seems. Will try out what I have and then look at the powder later if I start doing this more. Thanks. – Matt Aug 18 '15 at 18:22