Brush aluminum

There are numerous techniques and methods for finishing a metallic surface. Of course, this also works with aluminum. One of these refinement processes is the brushing of aluminum. However, since this process comes from the industry, the handyman can only achieve a similar result through "detours".

The appearance of a brushed aluminum surface

Brushed aluminum will be slightly dull while maintaining a certain sheen. Thus, the brushing of aluminum is in contrast to other finishing options of aluminum. These include, but are not limited to, the following techniques:

  • Chrome-plated aluminum
  • Gild aluminum
  • Polish aluminum
  • Oxidize aluminum
  • Anodize aluminum

Definition of the brushing of aluminum

The brushing of aluminum is a mechanical process for the surface treatment of aluminum. The industry uses cylindrical brushes that exceed in length the width of the aluminum workpiece to be brushed. In addition, the aluminum is also cooled by a liquid coolant during industrial brushing.

This is necessary because the aluminum surface discolors very quickly when heated. If the aluminum is even heated too much, bubbles form and destroy the workpiece. This is because the melting point of aluminum at 580 to 680 degrees Celsius (depending on the particular alloy) is relatively low and aluminum dissolves hydrogen when heated. Therefore, the casting of aluminum is problematic.

Aluminum brush by the handyman

Of course, do-it-yourselfers do not have the machines to professionally brush aluminum. Even not every metalworker has the expensive machines.

If you need a really professionally brushed aluminum surface, we strongly recommend that you visit a specialized company with appropriate machine equipment. The brushing of individual workpieces then falls financially not too much out of the ordinary.

Wet grinding achieves a similar effect as brushing

However, if you want to perform a surface finish of aluminum that is close in appearance to brushed aluminum, do not use a brush for a drill or angle grinder, such as the classic cup wire brush for the angle grinder.

In any case, work the aluminum manually

This would destroy the surface very quickly and burning of aluminum with bubbling can not be ruled out. Instead, you can achieve a very similar surface finish by sanding aluminum.

For this purpose, the aluminum is first pre-sanded with a grain size of at least 120 and then gradually reduced the grain size. At least with the 400 grit you should definitely use wet sandpaper.

Procedure for wet grinding of aluminum

You always grind in the same grinding direction and never in a roundish arc. Rather, you must make sure that the grinding direction always remains very straight. If you do not want to drag short but relatively long in length, you better grind slower, so that you do not drag in a bend, but actually straight.

Tips & Tricks

When brushing aluminum, remember to remove the oxidation layer as well. Some aluminum alloys have a specially applied oxidation layer with specific properties, the so-called conversion layer.

On the one hand, such a conversion layer would be destroyed during wet grinding or brushing, on the other hand, an uncontrolled oxide layer can now form. You can counter this with anodising or anodizing.

Video Board: How To Get Brushed Metal Appearance on Aluminum Fan Shroud - Eastwood