Soap Finish: The Mushy, Flat Stuff

soap_table_3_coats_IMG_9549

The soap finish after three coats.

After cooking the soap concoction and letting it cool for 24 hours, it became opaque and thickened to a mayonnaise-like consistency. Today I used it to finish the top of a worktable that is based off examples shown in the Tacuinum Sanitatis, a health book from the Middle Ages.

My goal with this worktable was to give the top what some people call a “scrubbed finish” with a painted base below. An authentic scrubbed finish is really no finish at all. It is the result of years of washing – just bare, almost-bleached wood.

A top with a scrubbed finish at the Cheltenham museum.

A top with a scrubbed finish at the Cheltenham museum.

The finish is so prized by some collectors that it is routinely faked by some dealers. (Or so I am told.)

Applying the mayo-like finish is quick and easy. It spreads easily with a rag. The water soaks into the wood or evaporates quickly, leaving a bit of a hazy sheen on the wood. A clean rag wipes off the excess on the surface. It takes about 5 minutes total to apply a coat of finish to the top shown.

soap_table_applied_IMG_9554

After the soap dries, it is indeed a dead-flat finish. Unlike other users, however, I didn’t experience any raised grain on the tabletop; my guess is that is because I didn’t use any sandpaper. The top is right off the jack plane. Even so, I sanded the finish lightly between coats with a #320-grit sanding sponge.

After four coats the top is very smooth and soft. Just what I wanted.

I’m going to experiment more with a soap finish in the coming months. I like how it can be used to produce a variety of sheens depending on the amount of water you add to the flakes. I also really like how simple it is and how difficult it is to mess up – perfect for the beginner. The added bonus is that it is much less toxic than many solvent-based finishes. I have enough volatile organics in my shop.

— Christopher Schwarz

The soap finish after 24 hours of cooling and setting up.

The soap finish after 24 hours of cooling and setting up.

About Lost Art Press

Publisher of woodworking books and videos specializing in hand tool techniques.
This entry was posted in Finishing. Bookmark the permalink.

18 Responses to Soap Finish: The Mushy, Flat Stuff

  1. Drew says:

    If you wipe down the finish with a damp rag, how quickly will the soap come off? How often did people reapply this traditional finish? Is it slippery when wetted?

  2. Paul Sidener says:

    Hello Chris,
    I fine your experiment to be very interesting. The table in the first picture is beautiful. I have a question, What happens if the table gets wet? Will it leave a mark you can’t get rid of, or would you just apply another coat and be back where it was before the spill?

    I am going to give this a try on something.

  3. Drew says:

    Does the soap finish become very slippery or bubble when wiped with a wet rag (like a table top is likely to be)? Would it be rubbed off quickly in use on something that is a high-traffic surface like a kitchen table and need frequent reapplication?

  4. brentpmed says:

    Would the properties of a traditional beef or sheep tallow lye soap change the look, durability and workability of a soap finish? I could picture the lye soaps having a bleaching effect on the wood. Have you tried a lye soap yet? Olive oil based Castile soap might be different yet.

  5. Alvin says:

    Can you use soap finish over milk paint or stain? Im loving those painted legs also. Looking forward to the book.

  6. g2-87cc707f0aa4e62f4a92f77f89ccba9d says:

    Beautiful finish and table design. Gorgeous tight straight grain too!

  7. ctregan says:

    This blog is becoming a Soap Opera!

  8. Rachael Boyd says:

    I have used a lot of finishes. paint (oil and latex), polys , shellac, milk paint, chalk paint, BLO and many more. now I will need to try soap,does ever end ? whats next keep them coming.

  9. waltamb says:

    Superb!
    Chris, I am as excited about these furniture designs and the finishing as I was was 44 years ago when I discovered the simplicity of Shaker Design.
    I cannot wait for you to finish the book on these and then do lots of videos and classes.
    This is a Home Run for Sure.

  10. Thomas Scott says:

    Hey Chris,
    Have you considered burnishing with the polissior?

  11. mbred says:

    Commission work for a Moravian giant? I think he’ll like it. I’ll be curious to see the answers to how it reacts with water.

  12. Niels Cosman says:

    I’m digging all of the “Furniture of Necessity” designs. This table’s a stunner.

  13. dan says:

    mine looked a bit different after 24 hours – a little translucent. I guess there’s room for experimenting with different soaps. I used this one http://www.amazon.co.uk/Grannys-Original-Soap-Flakes/dp/B00BUF3DUS

  14. I bought a bar of fragrance free Castile soap this morning. I plan to grate it and see what happens this week. It costs about $15/pound (~$4.50/5 oz. bar). I can buy it at the local yuppie grocery store – the one where the food is whole – instead of waiting on shipping.

  15. Mike Siemsen says:

    Be careful with that soap. Isn’t that what caused Ralphie to go blind in “A Christmas Story”?

    • Clay says:

      I did some samples about a month ago on birch, they turned out great. I just used Kirk’s Castile bar soap from the drug store (didn’t have time for shipping). I used a damp terry cloth rag, rubbed it on the soap gererously, then on the wood. Super easy. I basically followed Caleb James’ instructions, sanding between coats. I then buffed w/ a t-shirt cloth rag on a wood block to float it over the grain. I would like to try the flakes to see how the hardened soap finish compares. So far, new favorite finish.

  16. Bob Jones says:

    I’m guessing this is a finish typically used with light colored woods? Does it lighten the surface?

  17. helleraknes says:

    The soap does come off when c leaning, therefor you will have to have a thin soap solution for the ‘daily cleaning’. It is very stain resistant, beet root juice wont leave marks. It wont bubble when you wash it :-). If the surface turns greyish after some time, just wash it with warm water and give it a new fresh coating of thick soap solution.

Comments are closed.