5 natural ways to finish wood and how durable each finish is

Ways of protecting wood existed long before factory-made varnishes. The ability of some materials to keep water away or make the surface more resistant to scratching or rubbing led to their use to improve the qualities of wood. Waxes produced by bees or plant leaves, natural oils and tar left over from burning wood have been used to protect everything from tables and dowry chests to houses and ships. They are still used today, and the absence of chemicals in their composition is the quality most appreciated by those who prefer natural products. Find out which materials we can use and how resistant treated wood becomes below.

1. Wax

The most commonly used natural wood waxes are beeswax and carnauba wax. They are hard to find commercially in a perfectly natural state, most products are blends in which natural waxes are the lowest percentage. It is often replaced with paraffin made from petroleum or other synthetic products. One clue that the product is natural is the much higher price than synthetics.

Beeswax

Beeswax is easy to find and not very expensive. You can buy it directly from the manufacturer. To purify it, it must be melted and left to harden again. This separates water and impurities. If impurities remain on the surface after hardening, it can be washed and/or scraped off. Commercially available beeswax is ready-purified, but the truly natural kind is more expensive than the manufacturers'.
At normal temperatures, simple wax is far too hard to be used. This is why it is mixed with oils and/or solvents, also natural, and made into a dense paste. The most commonly used oils are linseed and tung. Natural solvents can be used citrus or turpentine balm oil. To make the mixture, the wax must be melted at a temperature slightly above 60°C. The paste is used after cooling. Other oils such as olive, coconut, walnut or jojoba are sometimes used in the blends. These are blends used to protect finished furniture. They are made in small quantities because there is a risk of the oil going rancid.

Find here some wood and furniture wax recipes.

Carnauba wax

Carnauba wax is secreted for protection by the leaves of the Brazilian palm Copernica Corifera. The very strong sun in the region and the high amount of water in the rainy season affect the leaves. The secreted wax protects them from dehydration, when the temperature is very high and the humidity low, or from rotting due to excess water and high temperatures.
Carnauba wax is harder and more resistant than beeswax. The higher melting temperature (82-86°C) makes protected surfaces more resistant. Due to its high hardness it can be polished. It is therefore also used in the automotive industry.
For wood, it is used as an emulsion or mixed with beeswax for better resistance to rubbing and abrasion. It is commonly used in floor waxes where, despite the small amount added, it greatly increases the friction resistance of the resulting mixture.

Resistance of wax finish

Wax, in general, gives the weakest protection of all materials used to protect wood. Protected surfaces are sensitive to hot objects, alcohol, scratching, printing. If not well spread and polished, it can collect dust and dirt. The use of wax is recommended for dense and hard wood with high resistance to scratching, abrasion and printing. Not recommended for exterior wood protection.

2. Oils

The most commonly used are linseed oil and tung oil.

Finishing with linseed oil

Linseed oil is the most widely used wood protection oil in our country. It is easily available and affordable. It is made by pressing flax seeds. The linseed oil obtained in this way cannot be used for wood protection because it does not shrivel. To reduce the flashing time, it is boiled at high temperature (boiled linseed oil) or mixed with drying chemicals called siccatives (sicativated linseed oil). It can be found in its pure state, as well as mixed with other substances or in paints. Check the label to see if it is a truly natural product.

Linseed oil doesn't film because it doesn't actually dry, it just flakes off when it's in a very thin layer. That's why you don't apply it thickly and wipe off the excess. If it's not wiped off, it turns into a sticky, gummy substance that collects dust and dirt. Its great quality is that it penetrates deep into the wood and thus protects it against moisture. The wood darkens slightly and becomes silky. Over time, linseed oil takes on a yellow tint.

Like wax, linseed oil does not make the wood resistant to scratching, rubbing or imprinting because it does not film. Resistance to humidity is good, but it is not recommended outdoors because rain washes it out quite quickly (6 months to 1 year). It goes into wood easily, but if water "runs" over it often enough, it comes out just as easily. It is recommended for finishing interior hardwood. The resistance of the finish over time is increased if coated with wax.

Finishing with tung oil

Tung oil is one of the oldest materials used to protect wood, mentioned by Confucius in his writings. It is made from the seeds of the nut of the tung tree (Vernicia fondii), native to China. Unlike linseed oil, tung oil is a film-forming oil and is very resistant, even to some chemical solvents (acetone). Being in liquid form it penetrates into the wood quite well, but less so than linseed oil because it has a larger molecule. Wood finished with tung oil darkens slightly in color and takes on a vivid, silky appearance. The color does not yellow over time.

Pure oil dries hard, but not as hard as linseed oil but only in a few days. To shorten the drying time, the oil is boiled at 260°C in the absence of oxygen (pre-polymerization). The resulting oil has a much higher viscosity and improved film-forming properties. It needs dilution to penetrate deeper into the wood. We preserve the natural character of the mixture by using citrus or turpentine balsam oil as thinners.

Tung oil can be used for interior and exterior wood finishing. It is resistant to moisture, scratching, abrasion, rubbing. The film does not deteriorate over time or change color.
The pure, natural product is very expensive. It is mostly found mixed with other oils and even synthetic products. There are even polyurethane varnishes containing tung oil.

Danish oil and oil blends

Mixture of tung oil with linseed oil is common in products known for wood preservatives. Danish oil or Kreidezeit oils are such products. Danish oil is a name used by several manufacturers, which is why the composition differs. The more expensive it is, the higher the tung oil content and the stronger the product. Kreidezeit oils have a constant composition because they are produced only by the German company Kreidezeit.
Oil blends combine the advantages of both types of oil. Linseed oil penetrates deep into the wood while tung oil makes a tough film. In the right formula they can be used to protect floors or wood used outdoors.

Finishing with mineral oil

Mineral oilAlthough it is used to protect choppers, bowls and other wooden objects in the kitchen and is food safe, it is not considered natural. It is a fraction obtained from the distillation of petroleum, which is then purified. More information about mineral oil and how it is used to protect grinders can be found at here.

3. Shellac

Shellac is the first varnish for the protection of wood and stringed musical instruments used since the 16th century. It is a resin secreted by a female beetle (Keria lacca) that lives on trees in the forests of India and Thailand. The beetle feeds on sap and deposits the resin on the branches, forming a tunnel. Once collected, the resin is melted, filtered and recrystallized for purification. It varies in color depending on the type of tree and the time of year in which it was secreted and can range from straw yellow to dark brown, orange, red or light brown. It is commercially available as flakes in various shapes and sizes, but less commonly as varnish because of its low resistance over time.

To obtain the varnish, the resin is dissolved in pure ethyl alcohol or industrial ethyl alcohol (denatured sprit). The varnish prepared does not last more than 3-4 months, after which it stops drying and remains sticky. It is the temperature that causes the deterioration. It is therefore advisable to keep the varnish cold.

Shellac has a natural sheen, but applying it is quite tricky and involves a lot of work. special technique and a very large number of coats. The resulting film is outstanding, with a natural sheen that can even reach a mirror gloss. With the addition of silicon salts, the appearance can become matt. However, the varnished surface is sensitive to water, alcohol and is not resistant to high temperatures. Defects in the area where a hot object has been placed can be repaired easily and locally, simply by applying varnish to the affected area. The repaired area will not be visible.

Shellac also has the ability to block tannin in wood.

4. Wood tar

There are two types of tar, wood tar and petroleum tar. Oil tar was used in the past mainly to protect railway sleepers. It is no longer used because it is considered carcinogenic. Wood tar is a natural product used for hundreds of years in the Nordic countries. It is obtained from both both resinous and deciduous, by dry distillation of the wood at 500°C. It is resinous tar, specifically pine tar, that is used to protect the wood.

Pine tar protects wood against water, moisture and insects, including termites. It is a thick liquid that must be heated to 60°C in a water bath before it can be used. Drying is very slow and can take several weeks, depending on climate and temperature. Drying can lead to staining. It is a 100% natural finish, with very good moisture resistance and can be used to protect wooden boats. It is mainly used for the protection of outdoor wood.

Pure pine tar is hard to find commercially. It is generally mixed with linseed oil and turpentine oil. Wood finished with these products can last outdoors for more than 20 years. More information on tar here.

5. Soap

Wood protection with soap solutions is a traditional way of protecting floors in northern Europe. It is still used to coat light-colored wood - maple, ash, white oak - because it does not change color or yellow over time. The resulting finish has a soft, pleasant, very low-gloss or no gloss. The film has the strength of wax and needs periodic refreshing.

The purest natural soap and water are used to obtain the solutions. The resulting solution is applied to the wood, allowed to dry and polished. Apply several coats, as with shellac. Find here two methods of finishing wood with soap, described in detail.

I hope you find the information useful. As always, additions are welcome. And if you have any questions or queries, please leave them below in the dedicated space. I will be sure to reply.