Of all the chemicals presented in this book, sodium hydroxide has perhaps the most lurid associations! More commonly known as lye and sometimes referred to as caustic soda, pure sodium hydroxide is not as widely available as it once was. This is because it is a necessary component in the creation of crystal meth. However, it is available through various online sources.
Another less than savory use of sodium hydroxide is to speed up the decomposition of dead bodies—a practice favored by a handful of notorious serial killers and drug cartel assassins because it erases features and reduces the corpse to a gelatinous sludge.
Sodium hydroxide is probably most well known, however, by its common name of lye and for its use as a drain cleaner. In fact, it is one of the oldest and cheapest cleaners around. In considerably lower strengths, it is used to make soap.
By now you are probably wondering why anyone would want to color their wood with this nasty substance! The reason is that sodium hydroxide produces a magical transformation in the color of wood—particularly on cherry and mahogany whereby their inherent reddish cast is magnificently enhanced.
Remember, though, that this chemical is also called caustic soda! Its deceptively innocuous-looking white crystals will burn your skin if you don’t wear gloves, particularly when the crystals are wet. Like sodium carbonate, it is hygroscopic, which means it has a strange ability to attract and extract moisture from the air.
Here’s a simple science experiment for you to perform: Place about a teaspoon of sodium hydroxide crystals on a piece of scrap wood and time how long it takes before water droplets appear. When done, use another piece of scrap wood to sweep them into the trash.
If you don’t neutralize the lye, it will eat through your finish, leading to blistering or pimpling.
Bear in mind that because you will neutralize the lye after applying it, you will need two complete sets of supplies: mixing containers, brushes, stir sticks, measuring spoons and cups, distilled water, rags, gloves and strainers.
It is best if you have all of these supplies ready on the work table before you begin mixing the sodium hydroxide solution. Be sure to wear eye protection as well as gloves and a mask.
Also, it is important to label your mixing containers beforehand because when the sodium hydroxide is dissolved in the water, it can look a lot like plain water, and you don’t want to mistake the lye solution for plain water when you start making the neutralizing solution. It has happened!
Sodium Hydroxide Solution:
1 tsp. of sodium hydroxide
3 oz. hot distilled water
3 oz. cold distilled water
Add one teaspoon of sodium hydroxide very slowly to the container of hot water because it can be unstable when it hits hot water and you don’t want it splashing out of the container onto you or other surfaces. Mix until thoroughly dissolved and then add 3 ounces of cold distilled water. Mix thoroughly. Strain this solution into a clean container and apply when it has come to room temperature. Wipe the surface with a rag before the solution dries.
Neutralizing Solution:
4 oz. white vinegar
4 oz. distilled water
When the sodium hydroxide solution has completely dried on the wood, it is time to apply the neutralizing solution. Be sure to use a different brush for this!
Slowly stir the vinegar into four ounces of distilled water and mix thoroughly. Brush the solution onto your project.
Always put the lid back on immediately and tightly seal the glass or plastic container that holds the crystals. This will prevent clumping, which makes the crystals much more difficult to dissolve and a tight seal will also maintain their almost infinite shelf life.
Now the main thing to know about lye if you are going to use it to color wood is that it is an alkali so you need to neutralize it with an acid after it dries, which in this case will be a solution of one part white vinegar to one part distilled water.
The color will lighten slightly after you neutralize it so you have to account for this. The finish color (the color of the wood after a clear coat finish has been applied) will match the color of the wood after the sodium hydroxide solution has dried. (You’ll recall that typically the finish color matches the color of the wood while it’s wet.)
Alder
Cherry
Mahogany
Maple
Oak
Walnut
