DIY Finishing - Crafting ideas - Finishing Techniques

Kreidezeit oil-based lacquers for natural and resistant exterior finish

Treating outdoor wood with oil is an old practice, both in our country and in other parts of the world. Linseed oil, common in this area, was used to protect wood against damp, the combination of burnt wood and oil being common for village fences. The problem was - and still is for linseed oil with no other additions - its low resistance over time, as the oil was washed away by rain in relatively short time. But there are several types of oil, and blending them together can produce much more durable finishes, even in harsh outdoor conditions. This is the case with the mixture of linseed oil and tung which is the basis, not only for Danish oil, but also for other finishing products. Kreidezeit, a German company that produces and promotes natural products to protect wood and house walls, has used the two oils, as well as other natural materials, to produce exterior finishing products with very good resistance over time. Kreidezeit products are distributed in Romania by Naturalpaint.

Why the combination of the two oils is a winner

Indeed, the mixture of linseed and tung oil has proven to be a good combination. The two oils have properties that complement each other resulting in products with superior qualities.

Linseed oil has a much smaller molecule than tung oil, which allows it to penetrate deeper into the wood and protect it from the inside. Tung oil has the ability to fully polymerise in the presence of air, hardening and forming a film. Mixing them in the optimum percentage results in an oil that protects the wood much better.

Kreidezeit's oil blend also includes turpentine oil, a product used as a natural thinner. Turpentine is a natural product made from resin collected mainly from pine (the living tree) but also from other resinous trees. Distillation produces turpentine oil. Boiled linseed and tung oils are viscous and need dilution to penetrate the wood better. Boiling the oils is done to decrease the drying time. Unboiled oils have a very long drying time of up to one month.

Pigments as a barrier to UV radiation

The ability of oils to protect wood against moisture is self-evident. But outside, wood is not only subject to the action of water but also to solar radiation, and simple oils, without the addition of another product, have no capacity to protect against it. Wood to which transparent oil has been applied will change colour over time, just like unprotected wood. This is why no product with good outdoor resistance is totally colourless.

The pigments used by Kreidezeit to produce oil-based paints or pre-coloured lacquers are natural, without the addition of chemicals or other auxiliaries. They also contain no lead or other heavy metals, so there is no health risk.

Kreidezeit's natural pigments can be found, in varying percentages, in the composition of pre-coloured lacquers or oil-based paints, but also as separate products with which lacquers or paints can be produced in the most interesting colours.

Pre-coloured Kreidezeit lazings

The coloured lacquers protect the wood, leaving its natural grain and pattern visible. Oil-based varnishes have the advantage of a natural look, as the film formed is almost imperceptible. The oil allows the wood to vary in size when the humidity outside increases or decreases, an important property for a product used outdoors. With oil-based lacquer finishes, the finish is elastic and there is no risk of cracking or peeling of the film.

The lacquers are available in nine different natural colours: pine, larch, walnut, light oak, antique oak, rosewood, teak, venge and ebony. They are perfectly miscible with each other, so you can get a lot of derivative colours. They can be used to stain and protect houses in bușteni, of panelling used to clad houses, to protect fences, wooden garden furniture, gazebos, pergolas or terraces. Not recommended for decks and outdoor floors if they are subject to heavy traffic. Being natural, they can be used to finish wood in children's playgrounds, cribs and playhouses or toys.

How to apply and...reapply

Kreidezeit pre-coloured lacquers are applied directly to untreated wood. It is sufficient polishing it white, then apply two coats of varnish, drying in between. It is not recommended to apply the second coat before the first one is completely dry. A 24-hour interval between coats at a temperature of 20°C is therefore preferable. Application is done with a brush, trowel or spray gun. Consumption is between 50 and 100 g/m²/coat, depending on the application method and the absorbency of the wood. Pre-coloured lacquers cannot be applied to wood covered with varnish or water-based finishing products (primer, paint). The wood must be completely stripped beforehand.

WARNING!After application, all used rags, oil residues and other auxiliary materials that have come into contact with the oil are placed in a bowl of water. Like all oils and lazines Kreidezeit is self-combusting. The sun and the heat of summer accelerate the phenomenon, but oil-soaked scraps and rags should also be put in water in winter.

"The 'ageing' of the finish occurs gradually over time and is recognised by the loss of the original oily, silky sheen and the appearance of a dry sheen. This is the moment that tells us the finish needs freshening up. Degradation depends on the intensity of atmospheric factors, so it is not possible to say exactly when refreshing should be done. Elements located on the north side of the house, in unprotected areas or where weathering occurs violently for a good part of the year, may need to be refreshed after 2-4 years. In the southern part of the house, in areas with milder climates or in more sheltered spaces, rejuvenation may be needed after 4-6 years. Simply wash the surfaces beforehand for degreasing and apply a new coat of lacquer.

Kreidezeit products are appreciated by professionals who use them to finish log houses, exterior panelling, windows or terraces. They appreciate the ease with which they are applied and reapplied, the easy maintenance and the natural look. And the fact that they are natural products is a plus that cannot be overlooked.

About the author

Mihaela Radu

Mihaela Radu is a chemical engineer but has a great passion for wood. She has been working in the field for more than 20 years, wood finishing being what defined her during this period. She gained experience working in a research institute, in her own company, as well as in a multinational. She wants to continuously share her experience with those who have the same passion - and more.

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