Structuring wood by sandblasting

Lately I have been asked by several people about sandblasting. As there is interest in this wood structuring process, I thought I would expand a bit on the subject.

What is sandblasting

According to the DEX, sandblasting is the operation of cleaning, smoothing or blasting metal surfaces with a jet of sand shot with compressed air. It comes from the French word sand which means sand. Initially sandblasting was used only for metals, but over time it began to be used on wood, to remove paint and varnish from older finished surfaces or to print various marks using stencils.

It was only one step away from being used for structuring wood. Now, the sandblasting method of removing early wood from the wood surface is commonly used industrially. The result is structured, 3D wood that imitates old wood ate weather.

The risks of sandblasting

It is not a method that can be easily used by everyone. It is practiced by specialists because it involves the use of special, pressurized guns. During the operation sand and pieces of wood bounce all over the place, which is why the sandblaster has to wear protective equipment. Because of the fine sand everywhere the air has to be filtered. Such work is carried out in special cabins.

There are also people who clean or structure wood without being in a factory. They have a lot of experience in the field, they know what is involved in using such a gun and the risks they are exposed to. They protect themselves very well with special suits or by covering their face and skin very well, wearing gloves and goggles. They usually work outside in open spaces, making sure there are no people around who could be injured. In any case, don't try such methods and guns without being very well informed beforehand and without ensuring the protection of yourself and those around you.

Equipment and materials

In general, blasting equipment consists of: a compressor, a tank for sand (or other blasting materials), a long hose that allows movement around the object to be blasted, a gun and a nozzle of various shapes and sizes, depending on the purpose.

Although sand gave the method its name, other abrasives can also be used. The least aggressive material, originally used for copper blasting, is baking soda (sodium bicarbonate). The low aggressiveness protects the wood so that bicarbonate can be used to clean old paint coatings from wood without the risk of damaging the surface. After the bicarbonate action, the wood stays clean and the fiber remains whole.

More aggressive materials such as sand or some natural materials - walnut shells, coconut shells, shredded corn cob, pumice stone - small metal or plastic balls are used for structuring.

Being an abrasive material, the grain size of sand is also expressed by numbers, in the same way as abrasive paper. Small numbers are for coarse, coarse grit, and large numbers for fine. Sand is available in grain sizes from 30 to 220, but 30 to 80 is recommended for wood.

How sandblasting can be used

Sandblasting produces wood with a structured surface, i.e. the late wood is brought out by removing the early wood. The process is most commonly used on resinous and oak or similar essences. Depending on the grain size of the material used, a more or less pronounced or more discreetly structured surface is obtained. Sandblasting produces a lot of broken fibers through which water can be removed. After sandblasting, the wood must therefore be polished and finished to prevent severe drying.

Generally sandblasted solid wood. However, there are also artists who sandblast veneer or very narrow planks of lumber, totally removing the early wood. What remains is a lattice of late wood with a very interesting pattern.

Sandblasting is widely used in industry to achieve antiqued parquet or other wooden objects that suggest the passage of time. Followed by a quality finish, with materials that contribute to the natural effect, wood products can be made that add value to homes.