Rick, I've also done some testing with the Iron Acetate.
For going dark, the wood needs tannins to react. White oak has them, along with red oak, cherry, and other woods. To really push the limits, the wood can be loaded artificially, usually with black tea or other strong tea. One can also buy compounds with tannin extract that work, but tea is cheap 😀
Make it as strong as possible, then really saturate the wood for the best black. You can see that the pores are still lighter, but this can be eliminated with some good soaking and scrubbing with a toothbrush to work it in.
To react, ammonia fuming or iron acetate will react, you just need to decide which is less toxic 😵 With ammonia, the wood wont get raised grain and you can do a project after tea-ing and final sanding.
Blackening is an old school process that everyone should explore, nice to see it brought up! 👍
Thanks SplinterGroup. Just to comment about ammonia fuming....it's slow, cumbersome to set up, and nasty on the lungs. Disposing of it is a pain too. But it is even and beautiful.
However ... Iron Acetate IMO is better in many ways.
Just sharing info and hopefully sparking interest in the many wonderful journeys in woodworking!
Thanks for posting this! I’ve done a couple small projects with acetate, but (as has been stated) you really need that high tannin wood to make it work. It’s another good tool to have, and I do like the idea of ebonizing with it, especially for decorative plugs or something. 👍🏼
Ryan/// ~sigh~ I blew up another bowl. Moke told me "I made the inside bigger than the outside".
Ryan ... for woods that are weak in tannin content you add it. This is done by black tea first. Let the tea tannins soak in some then add the iron acetate.
Gary G Nice. Need to see the difference with white oak.
Gary.... tannins in white oak tend to be less than in red oak. If I were you I'd test with and without using black tea first with the iron acetate. This will show you which you'll like before doing actual piece that you want it on. Pine is also weak in tannins but it depends on what type. Always test on the side first.
Just had another interesting effect. I brushed on some liquid ammonia on the red oak. I let it sit for about 30 sec until soaked in but not dry. Then I brushed on some iron acetate. The results were fast, surprising, and looked alot like "D".
Yeah, I’m aware of the tea trick…but the ammonia is interesting. I wonder if it’s accelerating the existing conversion, or making more tannins available of something…
Ryan/// ~sigh~ I blew up another bowl. Moke told me "I made the inside bigger than the outside".
RyanGi Yeah, I’m aware of the tea trick…but the ammonia is interesting. I wonder if it’s accelerating the existing conversion, or making more tannins available of something…
When fuming, Ammonia reacts with the natural tannins in the wood species. In this case red oak. It deepens the wood's color and enlivens the figure. However I applied liquid ammonia and it changed it to a tan color and the second I touched the iron acetate to it the surface went near black. Just awesome!
Actually, white oak has more tannins, though there are differences between sap/heart wood which makes relying on the natural tannins a fair amount of guess work.
I'm not sure of the chemistry between the tannins and ammonia/Iron acetate, but I'd assume that either will convert 100% of the tannin given sufficient time. I have got a very "pure" black with both, but nice thing about the ammonia is the depth of penetration. Helps prevent sanding through the color. Either will work well, I do a lot of fuming so I have a 30 gallon tub that acts as my chamber.
Not sure what peroxide (an oxidizer) does chemically, but that is a brown with punch.
Ammonia fuming red oak (no other treatments) typically will produce a greenish tint which I don't really care for.
It would be interesting to see if and how much that color shifts with different color boards and even sap wood. See if it is based on tannin or the acetate turning to rust (iron oxide).
