Stain Your Wood Purple Using Red Cabbage

DIY-ing and crafting is a great hobby and stress reliever for me, but I'm not set on one particular medium and tend to jump from woodworking to 3D printing to sewing an so on... It's all fun until you sit down and calculate how much money you actually spend on supplies that only get used once or twice. I have cans and jars filled with specialised varnishes, paints, waxes that are slowly drying out because I only needed a little bit for my project , but had to buy a quarter gallon. I like to experiment with home made concoctions whenever possible to cut the costs and possibly come up with new uses for certain products.

My newest project focused on home made wood stain, specifically purple dye I needed to stain a wooden chest. Before I used cabbage, I tried staining my wood with diluted food dye and acrylic paint, but final effect wasn't too impressive. Food dye was the worst, no matter what brand I used, I ended up with indigo instead of purple. Out of desperation, I decided to use red cabbage which, if you remember from chemistry lessons, has the ability to change colour. That turned out to be an additional bonus, because I was able to play with it and create different colours I might use in the future.

You will need:

• Red cabbage
• Juicer or food processor with a grating plate
• Strainer / sieve
• Cheese cloth
• Disposable gloves

Cabbage is not a particularly juicy vegetable, but even without a juicer you will be able to squeeze 1/4 cup of raw juice from a small cabbage. 1/4 cup allowed me to cover about 6 sq. ft of wood (only one layer), so if you have a bigger project in mind, you will need a bigger cabbage.

Use disposable gloves or even rubber kitchen gloves while working with cabbage. It will stain your hands. It's relatively easy to clean the skin with a bit of soap and a brush, but that juice stains cuticles and gets under the nails, and is very difficult to wash off. I tried everything to clean my fingernails and nothing worked, so for two days my fingers looked like I just escaped the morgue.

• Grate the cabbage in a food processor and transfer (few tablespoons at the time!) to a fine sieve.
• Push the cabbage with the back of your spoon until there is no more juice left to extract and repeat that process with remaining cabbage.
• You will be left with a foamy liquid and possibly few stray bits of cabbage. Run that liquid through a cheese cloth or a disposable kitchen towel to purify it.
• Your cabbage juice is now pure and foam-free. Transfer into a jar and keep in the fridge until needed.
• You can keep it in a fridge for a few days, but after that it will succumb to mould, so finish your project as soon as possible.
  
  

Red cabbage is used to dye fabric and there are a lot of Instructables and YouTube videos that show you how to do it. Most of them recommend chopping the cabbage and boiling it until all colour leaches into the water. I don't recommend this method, unless you want your house to smell for days. Grating the cabbage and extracting raw juice is quicker, relatively smell-free and final product is more concentrated.

Use a regular paintbrush to apply the liquid all over unvarnished wood or plywood. Leave it to dry naturally, don't wipe the excess off. It will be wet and nicely saturated at first, but as it dries, the colour will become more subdued. Second layer of juice, once dry, will give the wood more vibrant colour.

If you are not sure about the final result, test it on an offcut to determine how many layers will be needed and how saturated the colour will be once dry. Different woods produce different results and need different number of layers.

You can apply clear varnish once everything is dry completely (2-4hours).

For anyone interested in using the juice over wood filler- this is what happens. White filler turned grey and no matter how many layers of juice I painted over it, it wouldn't blend in.

You can experiment with your cabbage juice by adding different quantities of acid (lemon juice/vinegar), which turns the cabbage juice pink-ish, or adding alkali (bicarb of soda/soap/bleach) which turns it blue-green.

You can see from the pictures that wet and dry stripes look completely different. Wet blue stripes turned green and dark teal, wet dark pink turned light purple and very light pink turned darker pink.

If you are looking for a particular shade of pink or green-blue, you will have to test your mixture in 30min increments.

So, let's say you want a particular shade of teal - you will have to add a small amount of alkali to your cabbage juice, mix it, paint a stripe on your wood offcut and leave it to dry for 30min. After 30min, if you are not satisfied with the colour, add more alkali, paint another stripe and let it dry. Repeat until you get your desired colour.

It's important to test the mixture and let it fully dry each time more acid or alum is added. It looks completely different wet than it does dry and also, different wood types will yield different results.

The fun part of this project is the ability to change the original colour into red/dark pink or blue/green if you are not happy with purple. Simply paint lemon juice over the wood or apply a solution of bicarb and water and see the colour change before your eyes.