Discover the compressed-air blasting technique in 5 minutes

What is compressed-air blasting? ?

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.

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.

Compressed-air blasting, precision stripping for specific applications.
Compressed-air blasting, precision stripping for specific applications.
Photo CC Colby Gutierrez-Kraybill

Finally, compressed-air blasting is an abrasive blasting process by abrasion whose different parameters (nature and grain size of the abrasive, choice of airbrush 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".

The advantages of compressed-air blasting

As we have seen, the great strength of compressed-air blasting lies in its wide range of adjustment possibilities. Properly implemented by a trained technician, a compressed-air blasting machine can, for example, strip the varnish from a piece of furniture 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, an airbrush can deliver a very precise jet that will allow you to strip the wood of a chair without damaging its canework, or to clean the wood of a window 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 also helps to fix dust and prevent it from spreading.

A beautiful example of stripping terracotta floor tiles
Stripping terracotta floor tiles: before and after.
Photo DR - Lascombes Matériaux Anciens

Compressed-air blasting machine 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 machine is not far from manual stripping using a spatula, brush, and sandpaper (mechanical action). In reality, the effort required and the time required are unrelated: using an airblaster is so much faster and more precise that the comparison is easy to make.
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 machine overcomes these drawbacks by implementing a process of abrasive blasting that uses no chemicals or heat, yet is fast and precise.

If the advantages of compressed-air blasting machine had to be summed up in one word, it would be "respect".

On which surfaces?

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 stronger than the material to be removed. It should also be noted that rubber and blaxon react poorly.

An application of abrasive blasting machine for cleaning boat hulls.
An application of abrasive blasting machine for cleaning boat hulls.

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.

A truly ecological process?

Yes, definitely. Firstly, because it doesn't use chemicals and doesn't heat paints or varnishes, causing fumes, but also because of the nature of the abrasive 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

Compressed-air blasting machines are precise devices that allow multiple settings: stripping pressure, nozzle selection and adjustment, and flow rate adjustment. Furthermore, there are compact models, allowing them to be used in confined spaces (tanks, vehicles). Note that a compressed-air blasting machine is always associated with an air compressor to provide the essential pressure.

An example of a compact and handy compressed-air blasting machine.
An example of a compact and handy compressed-air blasting machine.
Photo CC Johann

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 efficient 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.

Photos

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.

Videos

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.

Sodablasting of wood : demonstration on furniture, beams, shutters, stairs...

Wet sandblasting vs dry sandblasting

Glossaire

Abrasive

In the compressed-air blasting process, powder is projected onto the surface to be sandblasted. It is (among other things) the hardness ratio between the abrasive and the surface that determines the speed of compressed-air blasting and the final condition of the surface.

Nozzle

A nozzle placed at the end of the lance or hose. Its shape and design determine the pressure, flow rate, and shape of the jet. Choosing the nozzle is related to the choice of abrasive and the compressed-air blasting machine settings. A nozzle can also be adjustable.

Air Compressor

Device providing the necessary pressure for the compressed-air blasting machine to project the abrasive under pressure. Depending on needs, a compressor can be electric or thermal (gasoline or diesel).

Chemical Stripping

A stripping method using chemicals to trigger a reaction with the layer to be stripped (paint, varnish, rust, grease, etc.) and change its nature. This phase is often completed by mechanical removal of the layer (spatula, brush, etc.).

Industrial Stripping

Stripping whose objective is purely functional, unlike paint or varnish stripping, whose purpose is primarily aesthetic. Industrial stripping can involve parts or tools exposed to aggressive products, corrosion, or grease. The final condition and adherence to the dimensions and surface finish of the part to be stripped are particularly important.

Thermal stripping

A stripping method that uses heat to modify the consistency of the layer to be stripped (mainly paint or varnish) to facilitate its removal using tools (spatula, brush, etc.).

Graffiti

As old as humanity (see decorated caves), the oldest graffiti is generally created by incising or scraping the surface. Nowadays, it is most often painted, and not necessarily in the desired locations (public spaces, storefronts, vehicles, etc.), thus requiring stripping.

Varnish

Varnish is a surface treatment that is more or less glossy and at least partially transparent. The purpose is to protect the wood from moisture and wear, and sometimes to stain it. A varnish is applied in a liquid state; the "drying" can result from the evaporation of solvents or a chemical reaction (e.g., polymerization). Older varnishes used natural ingredients, such as oil varnishes used in violin making, for example. Currently, most varnishes are chemically derived.

More...

Surface finishing List of different surface finishing on Wikipedia Sandblasting Sandblasting on Wikipedia Directive 2014/68/EU Directive of the European Parliament and of the Council on pressure equipment