In the introductory chapter about wood, we mentioned that wood fibres were able to absorb moisture from the air and evaporate it later, in dry weather. This process involves a change in volume: volumes grows or shrinks. With time, objects warp and untreated wood also gets dirty easily. Objects become so ugly that you are hardly able to restore them. Further problems are caused by wood decay fungi and insects. All these problems can very well be prevented by correctly performed wood protection. Most people think wood protection is synonymous with painting; it is a more complex process, however.
There is plenty of information on the Internet about painting and preventive surface treatment. There are many kinds of paints, impregnators, fungicide and pesticide coatings available. Some technologies, however, cannot be performed in a home environment.
In view of the latter, we will only focus on generally applicable procedures here that may be of interest for us.
Wood is a beautiful material. The wood grains and the knots in the wood make a unique, beautiful pattern on your objects. You should therefore try to preserve and, if possible, accentuate them.
Carefully performed surface treatment may keep your artworks beautiful in the long run.
Completed polished surfaces can be wiped off with a clean cloth. A paintbrush with soft bristles used for de-dusting only may serve you even better. With a paintbrush you can access difficult to access corners as well. For the best result use a compressor to blow out the dust: thereby you can de-dust your workpiece.
Next comes protection against fungi and insects which can, however, be omitted in our case. Since we make our workpieces for indoor use, they are not exposed to a humid or wet environment and fungi or insects cannot attack them. It is furthermore important that you should avoid contacting wood saturated with chemicals.
After de-dusting you can varnish or oil the wood. The easiest way of varnishing is by colourless varnish spray.
I like oiling as surface protection very much and recommend it a lot. It is environment friendly, it is a long-time solution for wood protection and the surface is easy to renew. The simplest and most easily available oil is linseed oil. Unfortunately it dries very slowly; drying may take as long as a week. For a long time the surface feels sticky. You get a more beautiful surface if you add white spirit to the oil in a ratio of 1:1. Walnut oil is simple to use. The only problem I have with it is its price: it is not cheaper than oils especially manufactured for wood protection. Danish oil is very good. It gives you a beautiful surface as is environment friendly. My real favourite is, however, Auro impregnating primer Nr.121. It gives a long-lasting coating even without a top coating. The surface not only looks nice but also has a silky touch. Auro No. 121 is furthermore saliva and sweat resistant, considering which it is suitable for treating children’s toys, too. Since the smallest container is 0.7 l, while Danish oil comes in 1 l containers, they last very long. So as to avoid making all the contents of the bottle dirty, I pour some of it into a 0.2 l bottle and use this latter for work. If you do so, do not forget to label the new bottle.
(Danish oil + small bottle)
Any of these oils can be applied to the surface by brush, a sponge or some strong paper towel.
Soak up some oil with the paper towel and apply it to the wood in a thin layer. In the case of carved objects, you can apply the oil to difficult to access parts with a small brush. In about 10 minutes’ time, wipe off the excess oil not soaked up by the wood with a dry towel. Apply the oil in two layers. Between the two layers, sand it carefully with 220 sandpaper and de-dust after sanding. Drying time is about 24 hours.
The easiest way you can protect your hands is by using disposable nylon gloves. After work you can wash out the brush with lukewarm soapy water.
If you want to paint the wood with colour paint and fill up the joints with wood filling material to make it mirror smooth, first decide what kind of paint to wish to apply as the top coating. This will determine what materials you can use underneath because not all chemicals are compatible with one another. There are water-based and solvent-based paints. With solvent-based paints you can almost always paint on top of water-based paints but you cannot do it vice versa. In the case of untreated wood you must most often apply a ground coat because the wood does not soak in the top coating evenly; staining can be avoided by applying several layers of paints.
In most cases you can work with acrylic paints, too, which produces fast and nice results. This synthetic resin-based paint gets stuck on almost any surface. It is not sensitive to wood-filling material, either. No ground coat is required because it does not leave any stains when drying. It is easy to purchase and children can use it, too. We almost always use acrylic paints.
If you work with chemicals, read the safety instructions and comply with them!