The orbital sander is different from normal belt models and from those equipped with a round sanding pad, also in terms of the type of applications.
The main difference between orbital sanders, those with belt and those with round pad, lies both in the type of movement applied to the paper or abrasive disc and in the management of the working speed.
In normal belt sanders, for example, the sanding paper is mounted on two rollers and scrolled quickly in one direction, while many of the round base sanders feature a rotating movement of the pad. The shape of the latter, however, is not decisive for the type of movement; in fact, orbital sanders can have both round and rectangular backing pads, depending on the model and its specific intended use.
The main feature of the orbital sander, therefore, to which we also owe its characteristic definition, is that of having a rotary movement which is precisely of the orbital type; that is, the central point of rotation of the pad is not fixed but oscillating.
Obviously it is not possible to establish which is the best sander only on the basis of the type of movement that distinguishes it; the latter, however, becomes decisive for the type of application of use of this electric tool.
The belt sanders and those with the rotating circular pad, for example, are ideal above all for roughing jobs on different types of materials; the orbitals on the other hand, apart from the type of movement, are also characterized by the possibility of being able to adjust the rotation speed more precisely.
Their characteristics, consequently, make them more suitable for finishing works and for specific applications, which we are now going to examine in more detail.
From matte to glossy finishes
As mentioned above, the orbital sander is mainly used for the treatment of the finest surfaces. After having roughed the most consistent roughness with coarse-grained abrasives, passed on the surfaces with the uniform movement of normal sanders, in fact, the oscillating action of the orbital sander with discs and fine-grained abrasive papers, allows to make the final touch in the process of grinding the surfaces of more “delicate” materials, such as plastics for example, and especially wood.
By adequately adjusting the speed of the power tool, but above all by dosing the force applied to it, it is possible not only to make the surface of the material smooth and uniform to the touch, but also to choose the degree of compactness of the same.
When you have to treat a raw wood surface with the orbital sander, just to give a practical example, you can easily choose to obtain a matt, satin or glossy finish depending on the type of grain used for the abrasive and the force applied to the surface. ‘tool.
The latter also plays a fundamental role for this type of application, the pressure exerted with the orbital sander in fact, unlike normal roughing sanders, must never be too intense to avoid the formation of irregularities.
The same is also true when working on materials such as plastic and metal, as any scratches, or line alterations, would be much more difficult to correct without substantially altering the continuity of the surface.
The orbital oscillation movement, in fact, is specifically designed to avoid this type of risk; However, this does not mean that if you exaggerate with the pressure applied, the possibility of damaging the area you are working on becomes less remote.
Special treatments for the application of chemicals
One of the specific applications of the orbital sander, using special felt or wool discs, is that of treating surfaces with specific chemical substances, such as mordant, waxes, waterproofing and polishing products; in these cases the orbital movement is exploited for its “massaging” action on the surface to be treated.
As for the metal surfaces, this means that the distribution of the product occurs in a uniform manner, which is very important since the purpose is to create a thin protective layer on the sheet; in the case of porous materials, on the other hand, such as wood, the orbital movement allows the substance to penetrate more effectively and deeper, increasing the yield of the treatment in terms of durability.
Polishing of metal surfaces
Aside from the applications described above, the orbital sander is mainly used for polishing surfaces. Furthermore, this particular use is inseparable from the steps described above; in other words, therefore, if the sanding and treatments for the application of chemical substances can be performed independently and aimed at themselves, the polishing of a surface cannot be carried out without first passing through a smoothing phase and a subsequent application of the specific substance that will give further emphasis to the polishing.
Also in this case the dynamics of use of the orbital sander varies, albeit slightly, depending on the type of surface on which you are working. Wood and plastic do not always need a sander to acquire a glossy finish, in fact, given the possibility of obtaining the same in a simpler and faster way, by applying lacquers or special paints specifically designed for this purpose.
The situation changes, however, when it comes to metal polishing, and here we must also make a difference between the various types of surfaces to be polished. In the treatment of large surfaces such as car bodies, for example, or the fuselages of airliners, the orbital sander becomes a fundamental and irreplaceable tool, as it is used both in the application phase of the wax, or specific polishing substances to as appropriate, both for the final polishing step.
The importance of using this electric tool, in these circumstances, is partly due to the aesthetic motivation, but above all to the functional one; the substance applied to the sheet in fact, as we mentioned in the previous paragraph, not only has the purpose of making it shiny, but above all that of creating an insulating layer capable of protecting the metal and any layer of colored paint applied to it, allowing water and dust particles to slip off without damage.