On the one hand, the darkening of the wood is a completely natural process of aging. Under the influence of ultraviolet rays, temperature extremes and precipitation occurs discoloration of the top layer of wood fibres, resulting in a wood surface acquires a uniform color of light gray color. The intensity of the discoloration of the wood depends on its degree of oxidation, and therefore the natural darkening occurs at different species of wood at different speeds.
Quite another thing if the lumber or wood appear distinct blue or gray-black spots. In this case we have to establish the fact of damage of the wood-molds.
In most cases the tree structure is not destroyed and its operating properties it does not lose, however, becomes a breeding ground for fungi which destroy the wood. Moreover, such a tree becomes unsuitable for use as a finishing material.
Types of brighteners
The bleaching process the wood surface is simply the discoloration of lignin or in the destruction and elimination of mold and wood-fungi and their subsequent discoloration.
Means for bleaching wood are divided into two types: chlorine bleach and a medicine that does not contain chlorine.
As the main active ingredient in chlorine bleaches are usually sodium hypochlorite, calcium hypochlorite, chlorine dioxide or bleaching powder. Atomic oxygen formed in the chlorine for bleaching as a result of the dissolution of the hypochlorous acid acts as an oxidizer which destroys the fungi and the bleaching of wood pulp fiber.
Without chlorine bleaches contain hydrogen peroxide or titanium, ammonia, oxalic or formic acid. These substances are bleach the wood due to the reaction of its oxidation by peroxy initiator and a small amount of oxygen formed during decomposition of peroxide compounds.
Name and brand of bleach we intentionally omitted, in order not to be accused of advertising some drugs undeserved and ignore others.
Getting whitening, you should be aware that miracles do not happen and the whitening process will be successful only on the surface of the wood, and deep wood becomes discolored just as much as you can penetrate the tool-bleach. This time is typically about 3-4 mm.
Before whitening it is necessary to clean the wood from grease, dust and dirt. If possible, the surface of the wood must be treated with sandpaper or a plane to remove the layer of darkened wood fibers, and then Polish it.
Otbelivala specific to each tool supplied with instructions for its use, but in most cases the whitening process is reduced to application on a wood surface means with the help of spray, brush, sponge or roller in the direction of the wood grain. After 20-30 minutes, re-applied a layer, then another.
After drying from the surface of the wood with a damp cloth removes stains and efflorescence, and then applied a protective textured coating.
Good luck with the bleaching of wood! Let you will succeed!