We differentiate between protection against pests and wood care. The biggest pest challenge is protection against termites, which are widespread throughout the Iberian Peninsula, especially in the coastal regions. But more on that in a later post. Oil based paints and varnishes are often used for colouring and caring for wood.
Oil has the advantage that it penetrates the wood and thereby increases its protection. Oil is flexible and follows the movements of the wood excellently, even in changing temperatures. Oil is water-repellent and at the same time it allows the wood to breathe.
But oil also has impractical properties.
Oil dries slowly. Oil smells for a long time and can cause allergic reactions. Due to the smell, it is not advisable for treatment in closets. Oil wears out more quickly, especially when exposed to sun and rain. Oils become brittle over time.
Linseed oil in particular should be viewed critically. The big advantage of linseed oil is that it is more liquid than most of the other oils. It can penetrate deep into the wood and therefore protects the wood excellently. The bad thing is, that linseed oil in particular dries very slowly. Pure linseed oil goes rancid quickly and offers no protection, cooked linseed oil needs additives that that are not necessarily ecological. Linseed oil has little resistance and is quickly washed away by the rain and also wears out quickly on indoor floor areas. Linseed oil oxidizes quickly in air, becomes brittle and yellow.
Natural paint manufacturers like to use linseed oil as an admixture with hard oils to make it easier to transport the harder oils into the wood.
What exactly is contained in the products sold as oils often remains a mystery. Acrylates are often added to improve the disadvantages described above. This is not only at the expense of the wood’s ability to breathe. There is an important difference between real oils and mixed products that can already be read from the instructions for use: If repairs are necessary due to wear and tear, surfaces that have been treated with real oils can also be partially re-oiled after cleaning with a damp cloth. However, mixed products must be sanded before a renovation coat; partial improvements are hardly possible without remaining visible.
As in my post about eco-paints, I would also like to take a critical view of nanotechnology here. Nanotechnology is undesirable in oils from a building biology perspective. Here is a link to the online book “The Whole Building Handbook. How to Design Healthy, Efficient…” with a few words about nanotechnology from page 26 on.
If it’s not about pests, the colour or preventing stains, it can also be a sensible idea to skip wood painting, especially indoors.
A natural oil paint manufacturer with transparent product information is KREIDEZEIT. Their products are also used extensively in Japan, an indication that, in addition to ecology, the product quality must be good (I use KREIDEZEIT-products, but don’t sell them).
embarro.blog 