While everyone has heard of "sandblasting", compressed-air blasting remains a lesser-known process to the general public since it is a more recent abrasive blasting method. Sandblasting has proven itself in the stripping of heavily soiled or corroded hard materials, but it remains poorly suited to delicate surfaces whose shape must be strictly respected. Sandblasting is also very dirty and not suitable for indoor use, especially in occupied sites. See this article (in French) to learn more about the difference between the two.
Compressed-air blasting solves these drawbacks by using softer abrasives with finer grain sizes, projected at a lower pressure. The abrasive, selected according to the surface and the expected result, is loaded into the pressurized tank of the compressed-air blasting machine. Pressurized air sprays it through a nozzle to produce a precise jet of abrasive projected onto the surface. The grains strike the surface and remove the desired layer (paint, varnish, rust, grease, etc.) from the surface by simple mechanical action.
In short, compressed-air blasting is a surface treatment process based on abrasion whose different parameters (nature and grain size of the abrasive, choice of blasting machine and nozzle, pressure adjustment) allow it to be adjusted to almost all surfaces and all situations.
Compressed-air blasting is also known in French as "aérogommage".
As we have seen, the great strength of compressed-air blasting lies in its wide range of adjustment possibilities. Properly operated by a trained technician, a compressed-air blasting machine can, for example, strip the varnish from a piece of furniture bought from an Emmaüs charity shop without damaging the wood or diminishing the profile of its moldings. It can also strip dirty old floor tiles while respecting the handmade and irregular appearance of the tiles.
With a suitable nozzle, a compressed-air blasting machine can deliver a very precise jet that will allow you to strip the wood of a chair without damaging its canework, or to clean a wooden window frame without leaving any marks on the glass.
Furthermore, the relatively low pressure used will limit the projection of abrasive beyond the work area. It is therefore possible to treat the beams or bricks of a room in an occupied house without turning it into a giant construction site. Simultaneous water misting (known as wet blasting) also helps to keep dust down and prevent it from spreading.
Compressed-air blasting should also be compared to other processes such as manual stripping using mechanical action, thermal stripping, or the use of solvents and chemicals.
In principle, compressed-air blasting is not far from manual stripping using a spatula, brush, and sandpaper (mechanical action). In reality, there is no comparison in the effort and time required: using a compressed-air blasting machine is so much faster and more precise that it is no contest.
Thermal stripping produces potentially toxic fumes when the paint or varnish is heated. Furthermore, excessive heat can damage the wood, scorching it, or even hollowing it out during scraping.
Chemical stripping is certainly the least environmentally friendly process, harmful to both the environment and the user.
Compressed-air blasting overcomes these drawbacks: the process uses no chemicals and no heat, yet is fast and precise.
If the advantages of compressed-air blasting had to be summed up in one word, it would be "respect".
Almost all! A careful choice of abrasive and proper pressure adjustment will allow you to strip any surface, mineral or organic, even the softest woods, even leather.
Compressed-air blasting is commonly used on:
The only limitation comes from the hardness ratio between the surface and the layer to be removed: the surface must be harder than the material to be removed. It should also be noted that rubber and imitation leather react poorly.
Its uses in the fields of construction, heritage, mechanics, and industry are obvious. Other uses may be more unexpected or surprising:
With its great versatility, compressed-air blasting is a process that will interest individuals, craftspeople, and manufacturers alike, given its vast range of applications.
Yes, definitely. First, because it uses no chemicals and does not heat paints or varnishes (which releases fumes), but also because of the nature of the abrasives used. Among those frequently used are:
Compressed-air blasting is clearly one of the most environmentally friendly stripping processes.
Some abrasives are of natural origin and biodegradable, while others are neutral and environmentally friendly (mineral powders). Furthermore, a compressed-air blasting machine uses much less abrasive than a sandblaster. Some abrasives can even be recycled and reused. Ideally, waste containing used abrasives and stripped materials should be processed by a specialized company.
Compressed-air blasting machines are precise devices that allow multiple settings: stripping pressure, nozzle selection and adjustment, and flow rate adjustment. There are also compact models that can be used in confined spaces (tanks, vehicles). Note that a compressed-air blasting machine is always used with an air compressor, which supplies the necessary pressure.
Wet blasting machines are compressed-air blasting machines that also spray water with the abrasive to keep dust from spreading.
The starting price for a compressed-air blasting machine is around $2,000, and this can rise to several tens of thousands of dollars for the most powerful models with full equipment.
Compressed-air blasting is a process that requires real expertise to get the most out of it.
Due to the numerous adjustment options and the technical aspect of the process, training is essential to master a compressed-air blasting machine and achieve good results safely.
Some beautiful examples of the use of compressed-air blasting in the field of antique materials, and more specifically on terracotta floors. The before/after comparison is always very telling! Photos kindly provided by Lascombes Matériaux Anciens.
A selection of videos showing all kinds of compressed-air blasting operations: these clearly demonstrate the versatility, precision, and effectiveness of compressed-air blasting machines!
Understand the advantages of using cool, dry compressed air in abrasive blasting.
Soda blasting of wood: demonstration on furniture, beams, shutters, stairs, etc.
Wet sandblasting vs dry sandblasting
A video showing real-life compressed-air blasting jobs on a wide range of surfaces: tar, fabric, wood, graffiti, steel, aluminum. (in French)
Examples of compressed-air blasting on delicate objects whose details must be preserved: wooden and metal shutters, a metal statue, a decorated wooden piece of furniture, a bicycle, etc. (in French)
The components of a compressed-air blasting kit: the compressor, the aftercooler and, of course, the compressed-air blasting machine. (in French)
A compressed-air blasting demonstration: connecting and setting up the equipment, protecting the technician, stripping a gate and a stone wall at height. (in French)
