Staining Wood with Cheap, Natural and Non-toxic Tea
March 15, 2010
A few months ago George Constance, owner of the online tea emporium Indonique.com, sent me a parcel of beautifully packaged teas. He had been asking woodworkers on Twitter to try mixing up a concentrated tea solution to use as a stain for woodworking projects, and tell him how they liked the effect. He would even provide the tea. I put my name on the list.
I got around to experimenting with the tea stains just in time for the Canadian Home Workshop Show. Anyone who was at one of my presentations last weekend will remember how excited I was about finding a new, non-toxic stain that's dead simple to prepare. And dead cheap too.
In the Indonique kit I found 3 different kinds of tea leaves:
- Rooibos (a red-hued, fruity tea)
- Black Assam (earthy black tea)
- 'Powdered Blend' (a finely ground custom mix)
George's instructions were to boil the tea leaves in 2 cups of water until the liquid was strongly concentrated, and then apply the hot slurry, leaves and all, to wood. I boiled and prepared each of the teas and put the preparations into separate jars.
I painted a little of each mixture onto a pine board. (Experimental digression: I also tried engraving the wood so that the tea would sink extra-deep into the broken fibres in whatever design I had etched. It's a cool effect.)
Tea imparts a warm honey-coloured beauty to pine and fir, and the stain deepens over time. It's subtle and easy to control by adding more coats.
The Assam produced a light ash tone (left). The Rooibos imparted a warm reddish shade (center). The 'Powdered Blend' gave me the strongest colour (far right), a nice deep golden hue. (You can see the original whitish colour of the board peeking through between the swaths of tea).
I was pretty jazzed by the success of the tea stains. I've been using aniline stains for the past 10 years to achieve these honey and ash tones, but aniline is toxic and the intensity can be difficult to control.
Just when I thought I'd hit paydirt with tea stains, things got even better.
Working with the teas reminded me of a favourite old standby stain - a handful of nails (or one 'bun' of steel wool) tossed into a covered container with a few cups of vinegar and aged for at least a week.
The resulting rusty stain creates a dark brown (on pine) or charcoal (on oak) effect as it reacts with tannins in the wood cells. I always have a jar of 'Rusty Vinaigrette' in the garage looking like a science experiment that became self-aware.
By the way, I also made up a turquoise stain last year by soaking pennies in vinegar. The stain is gorgeous but it's not stable so you have to clearcoat it after it dries.
Left: Rusty Vinaigrette
Right: Coppery Goodness
I was using 'Rusty Vinaigrette' to darken some chip-carved lines on a coat rack when I had a minor brainwave. The rusty stain interacts with the TANNINS in the wood.
And tea is full of TANNINS.
So, if I add tea to the rust stain, I reasoned, it should really intensify the chemical reaction and impart a deeper colour.
I made a sample board of my homemade stains and let it dry. Then I dragged a paintbrush dipped in George's 'Powdered Blend' through each sample. Instantly, the stains changed colour and deepened. I freaked.
I should have yelled 'Eureka' but I didn't have the presence of mind. The thin dark line in each of the samples is where I painted on one coat of tea.
After this discovery I played with several mixtures. I found that if I put a couple of coats of Rust on a pine board I would get a dull medium brown. But as soon as I added Indonique's Powdered Blend, the wood went black. BLACK. A gorgeous rich black I've never been able to achieve before.
I also discovered that you can control the hue of the stain by blotting the tea after applying it over the rust stain. That's how I perfectly matched the colour of aged barnboard on the cut edges of my Ghostwood key rack.
Tea grows mouldy after about a week, so I blended it in equal parts with the rust stain. The vinegar acts as an anti-fungal so the stain is now stable but weak, since the chemical reaction occurs in the jar and not in the wood fibers. So for most projects I will still make up a fresh batch of tea stain and layer it over the rust or copper stains to control the hues.
Cool eh?
Thanks to George at Indonique.com for having such a great idea, and for putting it out to the woodworking world in a spirit of collaboration. Now you can try it too; either experiment with your own tea blends, or ask George to mix you up some of that kick-butt 'Powdered Blend'.
When you combine the tea and rust stain do you strain the rust stain first?
Posted by: Debbie Scholes | February 07, 2015 at 11:21 AM
its only toxic if you drink it...so dont...do your research before you try scaring people.
Posted by: Erin | December 03, 2014 at 09:39 AM
Just a note of caution. You might be getting a nice green color from the copper in your pennies but I think it might be poisonous too.
Posted by: Sam | November 25, 2014 at 11:13 AM