I saw a guy on youtube using tea to add tannins to wood by using the natural tannins in black tea.
This is his web site. It has the video link.
I've got a strong mixture of tea steeping now. Already have the steel wool/vinegar mix. Going to give this a shot on some scrap 1/4 ply. I know the wooly vinegar mix turns the un faced side solid black. Will try this on 1/2 ply as well.
I've used that formula for years to age wooden repair parts on antique clocks when making repairs.
Here is a short how-to I did some time back Wood Aging
The process works well, but the older the mixture gets the stronger it gets. This isn't necessarily a good ting since you can easily "over-age" a piece. When that happens a bit of sanding will usually "un-age" the part a bit and make it usable.
Anyway, it works great and can produce some nice effects.
it works great.Tea just a little bit, coffee strong and steelwool vinegar also, just experiment a bit, with mixtures.
I use a coffee tea mix for a nice medium brown and steelwool-vinegar for a dark brown.
Nice link Tom T. Thanks for sharing. My results were good. just not what I was hoping for.
The first pic is of the dark side of my 1/4 ply scrap. The darker corner is where i used the tea first.
The second picture is the reverse side of this. Didn't seem to matter where the tea was. it's all black.
The third pic is of the end of a pine 2x4. Again the dark end is where the tea was put down first.
I'm going to try backing soda next. I also have a tube of M. Graham water color paint that's pure iron oxide. May try that with vinegar and again with water to see what happens.
Thanks for the photos, Rat. The suggestion to "Experiment" is definitely in order. There are a ton of variables to play with (Tea strength, how long the vinegar/steel wool solution sits, how quickly you neutralize the wood after application and type of wood). Once you get a feel for how the stuff will affect the wood, you can control things pretty easily.