Category: Finishing

If I ever write a book on finishing, I’ll probably call it “Farting Around With Finishes.” 

One of the things I like to do on a Sunday afternoon is mess around with dumb ideas. About 100 percent of the time, my results are ugly or unremarkable. But every once in a while I discover something interesting that eludes the rounding error of “about 100 percent.”

One of the things I love about old vernacular pieces are the (rare) unrestored finishes. The best of them have a dark and mellow glow that verges on black. They have a low luster, but it’s nothing like dried linseed oil, which can look flat and starved.

After talking to experts on furniture and finishing, I’ve concluded that many of these finishes are the result of soot from the hearth (consider what coal soot did to the buildings of the U.K.). And the shine? Burnishing from use and the natural oils from the body of the sitter. There also could be waxes. Grease from food. Soil from clothing. Water damage. Children. And on and on.

(The original finish on these pieces could have been anything from nothing/nekkid, to an oil, a linseed-oil paint or a wax. These made-at-home pieces were unlikely to have a fancy film finish applied by the builder, though anything could have happened to the piece in the 20th century.)

Last fall I took a trip to Europe to travel around with Chair Chatters™ Klaus Skrudland and Rudy Everts. We drank a lot of Belgian ale and talked non-stop about chairs for about a week. Near the end of the trip as we were driving back to Munich, I wondered aloud if it would be possible to create a finish that would somewhat mimic old finishes on vernacular pieces (without dangerous chemicals or a 32-step process).

I had a dumb idea. Perhaps the finish could be based on a plant oil that is similar to sebum, the oil and waxes made by our sebaceous glands to keep our skin moisturized. As it turns out, jojoba oil is similar to sebum. (There is synthetic sebum out there, but the sources I have found are too expensive to use as a furniture finish.)

Jojoba is inexpensive, widely available and edible (but not digestible). Like linseed oil, jojoba is a drying oil. It is combustible, and there is a small risk of it auto-igniting if you foolishly bunch up your rags. So take the same precautions as with all drying oils and dispose of the rags as recommended on the oil’s Safety Data Sheet.

So jojoba is indeed a good candidate for a wood finish.

The next hurdle was how to get the hearth smoke into the finish. My first thought was to grind up lump charcoal or simply get some ashes from the fireplace and mix it into the jojoba. My experiments with those sources didn’t go well. The finish felt really gritty.

The solution was to switch to carbon black. Carbon black is essentially soot that is used as a pigment in inks and paints, and to color the rubber in your tires. It’s cheap, and you can get it as an extremely fine and consistent powder.

So what happens when you mix together jojoba oil and carbon black? I started with 1 ounce of jojoba oil and mixed in 1/2 teaspoon of carbon black. I stirred it with a popsicle stick and within a few seconds the carbon black was evenly distributed in the oil.

Then I ragged it on a scrap white oak chair arm that has been hanging around my shop for a year.

Surprisingly, it looked pretty good. The oil gave the wood an orange color, and the carbon acted like a pigment stain – collecting in the wood’s pores and sitting on top of the wood. I let the finish dry for a couple hours then checked it again. 

The downside is that the carbon black rubs off on your clothes a bit. After the oil dried to the touch, I rubbed it quite a bit with clean, dry rags. The finish on the wood didn’t get any lighter, but I continued to get some carbon black on the rags. (Though it was less and less the more I rubbed.)

So next, I’m going to reduce the amount of carbon black in the mixture and see what happens. And I’ll try adding a spit coat of shellac to the sample boards to see if it locks in the black color. Third option: cook up some soft wax with jojoba, beeswax and some carbon black.

All this might be a dead end, but I enjoy the process (and I hope that maybe Lucy will get me a lab coat for Christmas – ooooh, and a clipboard).

— Christopher Schwarz

Applying a linseed oil and wax finish is one of the easiest things to do…

If. You. Follow. Instructions.

Every single problem I have encountered with applying this simple finish can be traced to not following the application instructions. Why is it always user error? Because almost nothing else can go wrong. The finish isn’t particularly sensitive to humidity, temperature or the way you apply it. You can put it on with a rag, steel wool, synthetic woven pad or cheesecloth. There are no brush strokes to overlap or tip off. There are no spray patterns to learn. Heck, the workshop can even be a little dusty.

So what can go wrong with this finish? Well, I’m sorry to say it, but it’s you.

Here are the instructions. 

1. Prepare the raw wood just like you would for any clear finish. Remove excess glue. Make sure all the show surfaces are prepared to the same level of refinement. Break the sharp edges. 
2. Apply a good coat of the linseed oil/wax finish. Saturate the wood, especially the end grain. Get the whole chair, box or shelving unit covered with the stuff. Look for dry spots (especially on end grain and in corners).
3. Now get a clean rag or towel (we use Huck towels). Rub the entire project until you have absolutely and positively removed all excess from the surface. If there is a greasy film that you can leave a fingerprint in, then you have not removed enough. You should keep rubbing the project until the wood is basically dry on its surface. It will feel a little cool to the touch but there should be no discernible greasy film.
4. Wait 30 minutes. Get a coffee or a glass of water.
5. Go back to the project with a clean rag or towel and rub it dry again. Some woods will leach out some of the oil after the first application, and you don’t want that stuff pooling on the wood. Get in the corners. It’s easy to miss a few spots on the first rub-down, so this is your chance to find the excess. 
6. Go away for two hours. When you return, the project can be handled. Sit in your chair. Move the shelves to their final resting place. 
7. Now wait for two or three weeks. Look at the project. Are you happy with the sheen? If so, walk away. Does it look a little dry? Then return to step two and apply another thin coat of the stuff.
8. Now wait a year. Look at the project. Are you happy with the sheen? You know what to do.

If you haven’t figured it out, the biggest error people make with this finish is they don’t remove the excess finish. They leave a little extra on top, thinking: “That will add extra protection.” Wax/oil finishes don’t work that way. When you leave a little extra, the excess bunches up like a rubbery scab. Or it refuses to fully dry. 

This problem is especially acute with casework. The woodworker finishes the interior of the secretary or cabinet then closes up the case – robbing the finish of the air it needs to cure. So the finish never dries. And it smells awful. If you use this finish on the interior of something, you have to leave its doors and drawers open until it cures (which is two to three weeks).

Most projects don’t need the interior to be finished (historically, finishing the inside of a piece was seen as a waste of time and material).

Finally, take the rags or pads and lay them out to dry. Don’t bunch them up – it’s a fire hazard. In Europe, many woodworkers burn the rags. In some parts of the country, they put the rags in plastic bags filled with water. I lay the rags out, and I have never had a problem.

Troubleshooting tip: What if you left too much of the finish on the surface, and it is a sticky mess the next day? Get a solvent such as low odor mineral spirits or a citrus solvent (limonene) and flood the surface. It will dissolve the excess wax and oil, and everything can then be wiped away. Wipe the project until it is dry and you are back to wood. Let the piece dry overnight. Then begin again with step two above.

— Christopher Schwarz

I’ve cooked up about 10 batches of linseed oil and wax in an attempt to make my own finish, but nine of those batches were unusable. Several batches were almost rock hard. Others were no different than thickened linseed oil.

One batch was perfect. But, of course, like an idiot I didn’t write down the procedure for that batch. I probably got distracted by a squirrel.

Until I get the recipe nailed down, I continue to use three commercial brands: Allbäck Linseed Oil Wax, Tried & True Original and Heritage BeesBlock. All three are free of harmful solvents. 

The only difference among the products I have found is their viscosity (and their price). The Allbäck is like peanut butter and costs $61 per quart. Tried & True is like snot and costs $35 per quart. And BeesBlock is like a thinned linseed oil and costs $42 per quart. I suspect the difference is caused by how much wax is in the mix, but I can’t say for sure.

I love these finishes because they are easy to apply, easy to maintain and they pick up patina quickly. In other words, they don’t offer much protection from life. But that’s the approach I have come to prefer for most of the things I make (when I get to decide on the finish).

Application

Most people put these finishes on too thick. And they don’t remove enough when they wipe it down. Here’s how I apply them. I use a 3M woven grey pad to apply the finish. I like this pad because its slight abrasiveness helps smooth any rough spots, especially up around the spindles where it is hard to work with sandpaper or scrapers.

I put the project upside down on my bench and coat every surface I can easily reach rubbing the finish in. End grain will need extra finish because it will suck it up and leave the surface dry. After I coat all the surfaces of the piece that I can reach, I let it sit for 15 minutes.

Then I take a Huck towel (a surgical rag with no lint) and vigorously rub off any excess finish. I keep rubbing until the surface is dry.

Then I turn the piece over and finish the rest of the surfaces, let it sit for 15 minutes and then rub it with the Huck towel.

I look for dry spots, especially on the end grain, and add some more finish. When I’m satisfied, I let the piece sit overnight. Then I rub it vigorously with a clean Huck towel. The finish is done.

You can apply additional coats of finish if you like, or you can put the project in service. After about a year you might want to apply another coat. Or let nature take its course.

— Christopher Schwarz