Iron Buff.

I'm not much of a risk taker in the world outside my shop. I wear my seatbelt, show up to my day job on time, and don't enjoy slot machines or lottery tickets.

Inside the studio is another matter. It seems like I enjoy it most when I'm pushing the boundaries. They may not be boundaries to everyone, hell, it may be old hat to some, but I'm content when something is new to me. It seems that when something is predictable and in my control, I'm bored.

I have a friend I owe a carved box to. A couple weeks ago I finally got him nailed down to some specifics regarding size and use. He's going to use it in conjunction with his own medieval reenactment and I've wanted to build a dry run of one of the chests shown in the Maciejowski Bible.

 The box itself would be fairly simple but I wanted to play with some of the treatments. The Box in the miniature is colored black and paint works and it is medieval accurate, but I wanted to try a different approach.

I have a blacksmith on the line for the lock and straps for the "good" box for the book, but I wanted to try and play with some off the shelf options from the home store to offer alternatives to readers. I also wanted to play with lining the inside of the box with some wood block printed paper after seeing some examples of this treatment in Victor Chinnery's book "Oak Furniture: The British Tradition"

I remembered reading about doing a surface treatment on oak that would stain it black. I think I first heard about it from Stephen Sheperd over at Full Chisel Blog, he refers to it as Iron Buff, which is probably a better name that what I've been calling it (dirty vinegar). It's basically vinegar thats been charged with iron filings and it so happens I started a jar priming several weeks ago.

I knew oak was particularly receptive to a reaction to iron buff, and it just so happens I had a board of white oak earmarked for this box already. All I had to do was saw it up and plane it down to size

A single coat of iron buff changed the color of the oak dramatically. The board in the foreground was connected to the stained one in the back. I know others have done this before, but for me this was magical to see. I just layered it on thick with a brush and set it on some painter's triangles to dry. After a few hours it was dry but still had a slightly vinegar/metallic smell and

I didn't want the box to smell like a pickle jar every time the lid was opened and the dried iron buff left a light residue that would rub off on my hands. I solved both of these issues with a coat of clear shellac.

I was curious how deep the buff had penetrated and the best way to figure it was to carve or cut into it. The geometric designs I came up with crossed a line into new territory for me.

A combination of 17th century techniques and influences of gothic tracery mixed with a lightly botched initial layout led to something terribly unique yet balanced in a pleasing way. I wasn't sure if I liked it at first but after passing by it In the shop for several days it's really grown on me. 

This may be the first carving I've done that I will be sad to let go of. 

Experiment in your shop. Accept the accidents and mistakes, roll with the punches, and you may just really like what turns up. 

Ratione et Passionis


  1. I've used the steel wool and vinegar trick on oak and walnut. Definitely try it on walnut if you like experimenting. Because it has smaller pores than oak it's an even deeper black.

    You can use it on wood that's low in tannin like pine or maple to give it a weathered look. It's the tannin that reacts with the dissolved iron to create the dark color. I haven't tried this, but I've read that if you soak a low tannin wood in tea (which is high in tannin) you can get it to turn darker.

  2. I've used it on Australian Mountain Ash, which is supposed to be a high-tannin timber but found a couple of pieces wouldn't take the dye. To try and rescue the job I experimented with tea and found the cheapest, nastiest tea from the supermarket produced the best results. If you can see the bottom of the pot, it isn't strong enough. :-) Leave it to soak overnight if you can.
    Iron in vinegar also works well as a black dye on veg tanned leather.


Post a Comment

Popular Posts