Our partner company in relation to painting and lacquering, Pintures and Lacats Toni Planas, provides us with a series of tips for the treatment of your outdoor and garden furniture.
Undoubtedly, among all the materials that nature offers us, no other is as practical as wood. What resists the passage of time better than a wood treated with protective products and that offers thermal and acoustic insulation at the same time? It is hard to say. To get this material to endure the transfer of daily life and adverse environmental conditions, it is good to know it better and know what its characteristics and qualities are.
The sun’s (UV) rays are a natural enemy of wood. They are responsible for this, if it is outdoors, lose its natural appearance and acquire a grayish tone. This is because the sun degrades a component of the material called “lignin.” From there, the rain removes the lignin, cracking the wood and giving way to the action of moisture.
On the other hand, water and humidity do not directly attack the wood, but favor the conditions for the development of fungi and insects. This material only ends up rotting if it is constantly wet, so when we have wooden elements outdoors, they need effective protection against moisture. When the autumn rains come we find the right time to protect it.
When talking about this term, we refer to the resistance that wood presents naturally in the face of attack by insects and fungi, as well as atmospheric phenomena. The difference between the durability of some woods and others, is due to the greater or lesser content of resins, tannins, or oils that permeate their internal tissues.
Very durable: iroko, teak, iron stick, guayacán, ukola.
Durable: mahogany, oak, chestnut, red merenti, cedar.
Durable medium: American oak, pine, fir.
Not durable: raft, poplar, ramín, birch, maple.
We already know that, for garden furniture and exterior carpentry, we will opt for tropical wood.
Characteristics that wood protectors must meet
The products offered by the market for the protection of wood are those that, applied in appropriate dosage and form, take care of this material against one or more destructive agents. In general, we will state its ideal properties:
Can be applied to all types of wood.
Be effective against insects and xylophagous fungi.
It should not be harmful to the environment.
It must be compatible with the subsequent application of paints and varnishes.
It will not affect the properties of wood.
It will not leave residual odors.
You must maintain your long-term protective action.
Due to its effectiveness against wood destroyers, the materials can be:
Fungicides (protect against the action of fungi), insecticides (insects), water repellent (moisture), pigmented (contain pigments that protect from the action of the sun).
The application system is usually by brush or brush (although it can also be applied by spraying, dipping, injection and autoclave). Brushing is the simplest impregnation system since we only need a brush or brush.
To obtain a good decorative finish, it is important to prepare the material. On new woods, the surface will be devastated with a coarse-grained sandpaper and then with a finer sandpaper, imperfections are eliminated until a smooth and smooth touch is achieved.
Sanding will always be done in the direction of the grain. We will remove the dust with a brush or with a slightly damp cloth. It is also advisable to sand gently between application hands, to improve the final finish and the adhesion between layers.
It is always necessary to remove the layers of varnish or paint that have been previously applied. Wood needs to breathe and protect itself, so it is necessary to remove the barriers that form varnishes and paints.
The exterior wood protector is essentially composed of oils that are impregnated in the wood fiber, nourishing it and leaving a natural perspiration. In wooden garden furniture, we will use teak oil.
For the compounds by rattan, banana or wicker, being their construction material different from wood, they should always be covered in terraces or porches, or not left outdoors, since the effect of rain and humidity would be fatal. These can be varnished at the beginning of spring and autumn.
We should never apply a protector on varnished or painted surfaces, because it would be inefficient and evaporate slowly. To remove the previous layers of varnishes and paints, mechanical means (sanders, hot air torches) or chemical means (strippers or paint removers, following the manufacturer’s instructions) can be used.
Now only sanding and cleaning remains, brushing with the protective oil (from teak for garden furniture, protective oil for exterior carpentry), retouching defects with wood pulp, sanding gently and applying protective finish. The best products are undoubtedly those offered by renowned brands and that we can find in DIY centers.