Soap Finish

Soap Finish

The Natural Look

Published: 7/29/20
By: Brennen Waldron

A soap finish is a simple wood finish; easy to apply, does not affect the wood’s color, and arguably the cleanest finish available. Other wood finishes such as polyurethane, wax, and oil are more common and available at most hardware stores. Although they are most popular in these regards, these finishes tend to discolor the wood and most often contain toxic chemicals. Unlike these finishes, soap finish is not easily found on store shelves and not commonly used today.

Apply a soap finish by using a rag to cover the desired work surface. After letting it sit for 5 to 10 minutes, buff off the excess with a clean rag. You will end up with a light sheen, thin coating similar to a finishing wax. Depending on the desired hardiness, soap finish can be applied as many times as you really would like, although 4 to 5 coats are the consensus for hardy protection. You may also be pleased to know that soap finish can be made in your kitchen using only two ingredients: pure soap flakes and boiling water.

Two standard recipes produce two different forms of the finish, the slurry, and the wax. The slurry is best to cover large surface areas because it is easy to spread and gets in the tight corners. The recipe for this mix is one part pure soap flakes and four parts boiling water. Let the mixture sit overnight after mixing. The consistency of the resulting mix is similar to applesauce.
Another form of soap finish is similar to a bar of soap and only requires one part soap flakes one part boiling water, again let it sit overnight. I find this “soap bar“ easy to store and bring out anytime you need to touch up a surface.

To show the effects of soap finish on different wood species, I tested on pine, cedar, ash, oak, and walnut. The images may seem underwhelming as there’s no significant difference between the raw and finished woods. But that is exactly what draws me to this finish; you protect the wood without compromising its natural look.

Top: Soap finish on pine, ash, oak, cedar, walnut
Bottom: Unfinished wood

Context




Traditional Soap Finish, with Christopher Schwarz

 


Thoughts

– Why choose a soap finish?
– How does the vulnerability of a soap finish change your interaction with objects it adorns?
– What is a project you think wood benefit from a soap finish?