Introduction: Steel Wool and Vinegar Wood Aging/Ebonizing/Weathering (A Controlled Experiment)

Picture of Steel Wool and Vinegar Wood Aging/Ebonizing/Weathering (A Controlled Experiment)

I have read a lot about using Steel Wool and Vinegar to age/weather new wood. I guess the acidic solution reacts with the Tannins in the wood to create a chemical reaction to weather and essentially stain the wood with somewhat of an acid wash. I decided to do a test of various commonly found woods to see what type of coloration and saturation I could come up with.


I Started with a test board with a bunch of different woods.



You can see that there are two rows of test area that has been treated with Black Tea. Many woods have high tannin concentration, but there are some like PINE that are low. Adding a tea mixture provides some tannin to aid in the reaction. This will give us an idea of what type of depth of color we can achieve.

Step 1: Different Vinegar Mixes

Picture of Different Vinegar Mixes

I decided to test just two Vinegar choices, Balsamic Vinegar and Apple Cider Vinegar. White Vinegar is also a choice, but knowing that I want a darker stain for the furniture that I will be using this on, I went with what I had heard would make a darker tint.

I chose Mason Jars from Target that were 16 oz each. I am sure that I could go much bigger, but this was the trial. I will adjust mixture if necessary.

The first Jar you see is Apple Cider Mix, with ONE WHOLE steel wool (0000), ripped into pieces to try and speed up the process of degradation. 

The Second mix is Balsamic Vinegar with ONE WHOLE steel wool (0000), ((I also did a jar with half of a steel wool, to see if that would make a difference).

The third Jar, (Bigger one) is bleach, with various woods soaking inside. My plan is to wire brush them to remove the softer fibers that have been weakened by the bleach. Then I can treat them with the wash and see how the grain looks.

You can see my tea mixture here also, and the pouring of the Vinegar.

Step 2: After a Couple Days.....

Picture of After a Couple Days.....

Here is what everything looks like after a couple days. This was actually a really fun experiment. Weathered and old looking in a matter of days!!!


regniweol (author)2014-04-21

This is a very nice experiment! Thanks for all the info, definitely helps with some projects I'm doing, and jives with some experiments I've been up to.

I'm a synthetic organic chemist so I thought I'd lend some of what I know and what I've found, and try to troubleshoot a little for people below.

It's already been discussed, but the desired reaction is the iron acetate is reacting with the tannins in the wood or the tannins you've put there (a little more on that below***).

If you are just having issues making your iron acetate solution I've got a bit of advice to add to kjbills' below.

1) If there is any oil or a coating of organic matter on your steel wool, it'll definitely slow up the process a bunch. This includes trace oils from your skin! - Try not to handle the steel wool without gloves, preferably not latex ones.

- You can rinse off residual oils (maybe from the manufacturing process or something, who knows?) with mineral spirits, then let it dry completely to ensure the surface is free of oils before you begin.

2) You can really speed up your process by adding some other household chemicals and they shouldn't alter the reaction down the line.

- To your vinegar you can add a capful or two of a disinfecting hydrogen peroxide solution. This is the safest, easiest way to speed things up, because household hydrogen peroxide is very dilute. Don't use industrial stuff, because that could pose an explosion risk (anything more than say 15%).

- The intermediary option is to add a capful of household bleach to the vinegar. Bleach is one of the better oxidants available to you in the home and will corrode exposed iron quickly. To give a slight boost to the process, you can again add some salt, but this makes it a little more dangerous because it borders on option three, the most dangerous:

- In lab, sometimes metals deposit on glassware and you need to dissolve them off. We use a solution of very strong acids, which you should not use. However the gist is this, those acids aren't acting primarily as acids, but also a so called 'radical oxidant': chlorine-radical (or Cl-dot). This is just a very powerful oxidant, and it will corrode iron and many other metals in no time.

- The only reasonable source of Cl-dot for you is probably from a mixture of ammonia and bleach. This reaction could be quite dangerous because it will generate a small amount of Cl2 gas, do it outside, read below! Place your steel wool as above in a mason jar, add 1/4 inch of household bleach (make sure to wet all the wool, even if it isn't covered), then drop in a capful of household ammonia. Cover the jar LIGHTLY so that it isn't sealed and let it sit for a day or so. Then you can carefully add your acetic acid. The bleach will break down in the sunlight to water and chlorine, and it and the ammonia will quickly evaporate off, leaving iron oxide in solution which will quickly exchange with your acetic acid to make iron acetate.


Why use these chemicals???

Most of the dissolution of iron is probably occurring in a reaction between the thin layer of iron oxide (rust) on the surface and the acetic acid, but once it gets down to the layer of 'elemental iron' as in pure Fe(0), an oxidation reaction needs to take place to make more iron oxide. Acetic acid itself isn't going to achieve this very well; it isn't a good oxidant, and household vinegar probably isn't strong enough an acid to corrode the metal all that much. If you observe this reaction, the oxidant is actually probably oxygen from the air, or radicals generated from UV light so that's pretty slow. You add an oxidant to promote oxidizing the iron and pulling it into solution for/via ion-exchange.

*** What is going on between the iron and the tannins???

- Ok, tannic acid (and other tannins) are big organic molecules ( made up of highly-oxygenated 'aromatic organic' units. A tree 'uses' chemicals like this (we call them siderophores) to 'grab' iron for various uses (nutrition, antibacterial etc.). Tannic acid is good for this because all of its oxygens have a bunch of negative charge and they can 'grab' onto iron and not let go without necessarily making a bond (we call this an ionic, or dative bond, rather than a covalent bond).

- When the tannins go out and grab the iron, the entire iron-tannic acid thing is now kind of a new chemical, which we call a 'complex.' This complex is what is colored. The reason it has color is that the iron and the aromatic ligands, share electrons really freely across the entire system: A little bit like a battery (the positively charged Fe) connected to a network of wires. And these wires happen to be attractive to light in that if a photon hits them, they absorb it easily, then share it all around the circuit, and eventually spit it back out as a photon of a different wavelength. Each complex is different, but this one spits light back out as this darker color.

FINALLY: Why do I care?

1) If only because I've read this far


2) At the end of the day it's not IRON ACETATE, but solubilized IRON(II) or IRON(III) that is doing the job. You don't NEED vinegar. Any other iron salt will do. This might be cool, because liquid ammonia also will dissolve iron and ammonia is used to darken wood on it's own. In this way you might see some sort of interesting effects by combining the two chemicals.

3) Maybe you want to take all of this even one step further. You know that iron behaves in this way, but it's possible other metals will too. Please be safe and research what you are doing, but I've been experimenting a little with solutions mixed with other metals, like aluminum. I'll try to update people if they are beneficial...

Solipsis (author)regniweol2017-10-05

Thanks for the elaborate response.
I do have some comments and questions.
The ebonization is I think a complex balance between any leftover acid bleaching the wood, iron(III) reacting with tannic acids to form iron(III) trigallate (a derivative not tannate) and the presence of leftover iron acetate.
Bleaching will lighten, the iron trigallate is blue to black and the iron acetate is a dulling brown solid.

I would advise against allowing too much bleaching though am still figuring out if a lack of tannins can be somewhat reliably supplemented later.

The iron acetate might be dissolved in alcohols but that may also pull them into the wood depending on your concentration and the amount applied.

If you make an iron acetate solution, adding chems to help the oxidation will only be useful if you have no time to spare.. Otherwise they should be avoided IMO as they can bleach the wood which you will really see in certain parts of the wood.
Iron acetate has bad solubility in water so as you generate it it will also deposit as nasty brown frothy stuff. What is the point of speeding up the process if it will just reach saturation quickly and deposit?

I have yet to master the tricks of excess acids and iron acetate precipitation on the wood though..
Looking for tips on getting out the iron acetate, ebonizing the parts resistent to blackening and info on whether ebonization can overcome all bleached spots...

Careful with aluminum etc, its toxic..
Iron(III) might be too though ib different ways i forget

Randomlycrazy1 (author)regniweol2016-12-24

Love finding the chemists comment on these things. Especially the organic chemists who actually care about educating the public. Thank you for your contribution to the community!

JenniferC212 (author)regniweol2016-04-27

Thanks so much for this! My solution wasn't doing much of anything and i was about to go buy regular wood stain from home depot...but then i read your post, which was very interesting and informative! I added a splash of bleach and the solution immediately started to change colours...thank you! Science is awesome!!

Pace1128 (author)2016-07-30

Can tannins be added to wood? To pine , for example, to made the color more uniform?

Randomlycrazy1 (author)Pace11282016-12-23

Great question! I've done some digging into this, as I'm interested in how other people have approached this technique. Tannins are able to be artificially added to wood. The article mentions using Black Tea, which is known to be high in tannins and holds a special place in my house for making homemade wine. However, not all woods will require extra tannin to be added to them. Soft woods, such as pine may require a little extra help.
-Chemistry student, homemade wine enthusiast, paramedic, honey-do man

Rosebuddog1 (author)2016-09-05

Need to get copper/ patina on alumin I like a little auqua patina mixed in. Any suggestions ?

Helen Michelle (author)2015-08-06

Hi there, This is my before and not quit after project.. I love the grey color and I would love to seal it without changing the there a way that I can do this without changing the color? Thank so much!!

renroc (author)Helen Michelle2016-08-29

Hi Helen, can you tell me what you used to get the colour on the table. It looks great and just what im looking for on a set of pine shelves. Hope its not too long ago. thanks Peter

CoreyT18 (author)Helen Michelle2016-04-13

Water-based poly dries without the amber tone of oil based polys, and you can find them in a satin or matte finish depending on how flat you want it to be.

Dan Solo (author)2016-04-16

I tried the mixture and after more of two weeks the wool still remains as the first day, it not melted a bit. What I am doing bad?

ElifK3 (author)2015-09-06

Daniel AlejandroG (author)2015-06-17

it's a great idea to document this experiment, this is just what i needed and didn't think i would find. The only con is that i can't read the lines on the wood. I am interested on the darkest one...

I agree on this, a chart explaining what was used with a picture of that outcome would make this an ace instructable. The picture isn't the clearest to work out your results.

However, great job!

pb404 (author)2015-07-23

Regniweol thanks for providing the science behind this! I've been using vinegar steel wool stain for a while but was looking for a way to speed up the process. The last batch I made sat for about a month and became way less potent. Making a new batch that's two days in but I need to use it ASAP. Gonna go try adding some hydrogen peroxide now.

Tip for those wanting to get aged wood look, get some cheap cedar wall planks (6 in a pack at Home Depot) then scrape and dent the crap out of them with stuff in your garage, wipe clean, lightly burn with a torch (I use my cooking torch) to bring out the grain texture then stain with the vinegar stain (I just used white vinegar and steel wool) that is 3 or more days old. The longer it sits the more potent it gets, but after about 2 weeks the strength seems to start to weaken. Beautiful! The dents and scrapes are a darker color and overall it has a nice grey brown color. I should probably just do an instructable for this but I'm too busy aging wood ;)

louisyisrael.chardonne (author)2015-01-12

I would say that this is very close to the principle of iron gall ink making

All my best

_Marc_74 (author)2014-11-26


im hoping for some advise.

I would like to add just a slight aged tone to this box

i do not want a grey colour just a slight aged tone, only slight darker but with extra character. unsure if should use vinegar/wool or tea etc etc

any tips you could advise?

liliana.ferreira.397501 (author)2014-11-12

Can you tell me what the fourth row from the top is? How did you get that colour on the pine?

pmk222 (author)2014-09-02

I went to a woodworking studio that was making chair sets for an auction that was being held to benefit the replanting of white oak trees in the area, the wood being used was here when the city was being settled so it had a real meaning for our area. there were two sets of six chairs both were white oak with walnut backs. half the chairs were ebonized and the other half were not.

the half that was not ebonized we separated the wood that had iron stains (essentially a natural version of the ebonization process) but the half we ebonized turned a really cool dark purple/black color.

the person who owned the studio told us that white oak has one of the highest concentrations of tannin but you can get tannic acid as a powder (used in making wine) from wineries and you can add that to the mixture and let the wood soak for a while to create either a darker shade for make wood that normally doesn't have a high concentration of tannic acid ebonize as well.

Mistycedars (author)pmk2222014-11-08

Sounds like the Northwest Woodworking Studio in Portland Oregon. I was able to help with the chairs for a couple days.

brian.sessums (author)2014-10-20

I tried 1 part vinegar, 1 part hydrogen peroxide, to the tune of half a mason jar of each fluid, along with the nails and steel wool. I put the mason jar lids on, set them on a shelf and went back to cutting wood. I anticipated checking on them in a week. That was before I noticed the swollen metal lids and bubbling. The jars were very hot and I felt they would explode if I did not rush them out of my garage and smash them myself on a tree, which I did. So, go easy on the peroxide if you keep this concoction in your house or garage, or just don't add it would be a safe bet.

Vincent_Kille (author)2014-03-30

Nice post, thanks for the instruction!
How did you add the tea mixture? Did you mix it with the vinegar before coating the wood or did you add the tea mixture to the wood and then coated the wood with the vinegar?

jezibel (author)2013-09-11

So, I'm using plain white vinegar and regular steel wool I'm a jar. I was expecting some kind of color change, but after 24 hours it still looks like plain old steel wool in clear white vinegar. I left it over night, as well as putting it I'm the sun today. Is there something else I should be doing, or is the color from the other products not the vinegar itself?

kjbills (author)jezibel2013-09-12

From my limited knowledge on all this, the reaction in the jar is much less important than the reaction on the wood. The jar is just to produce an acidic, metallic mixture that will react with the tannins and wood fiber to age and weather it.
Here are the ways you might run into trouble....

1) Steel wool is too thick or vinegar too diluted or cheap to dissolve enough of the steel wool in 24 hours. Break up the steel wool so that the most surface area is in contact with the vinegar. I didn't use white vinegar, so maybe it just doesn't change color, but the reaction is still happening....

2) The wood you choose has a big influence on how the color change takes place. Just remember that the reaction takes place with the tannins and so some woods will not change like others. Pine has very low levels, and will not darken or react much unless you add something to react, so that is why the Black tea was added to the mixture or pre-applied to the wood. Hope that helps.

I would test your mixture on a piece of scrap wood (Same wood that you are going to use for your project) and see if your current mixture works, regardless of wether it changes in the jar or not.

romonster (author)2013-09-07

Think you could give a list from top to bottom of the combinations that you used. I see that you wrote them on the side but I am unable to really make it out. Thanks in advance. This is really what I've been looking for.

kjbills (author)romonster2013-09-10

Okay, I will try to remember exactly what order they are in.

Here goes.

Very top section, No Treatment
2 Coats of Apple Cider Vinegar mix
1 Coat of Apple Cider Vinegar mix
1 Coat of Apple Cider Vinagar mix WITH BLACK TEA
1 Coat of Balsamic Vinegar mix
1 Coat of Balsamic Vinegar mix WITH BLACK TEA

Hope that helps.

cad_il (author)2013-06-18

Would this work for exterior applications? A cedar deck for example? Would it rust?

waldaddy (author)2013-04-12

Adding watercolor paints to white vinegar makes for some pretty nice stains too.

ccrome (author)2013-03-26

I love to see real science used on an instructable :-) Science doesn't have to be complex or difficult -- a simple method gives you a great array of choices.

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