Degrease aluminum

Before aluminum can be further processed, it must be degreased. Specialist shops and specialist retailers offer different approaches here. Below we have listed for you the typical applications for degreasing aluminum.

Degreasing versus pickling aluminum

Degreasing is closely related to the pickling of aluminum. As with pickling, in addition to the fat layer, the oxide layer can also be removed by degreasing. There are various processing methods in which this degreasing is extremely important, such as aluminum painting or gluing aluminum.

Chemical process for degreasing aluminum

In the past, trichlorethylene or perchlorethylene (halogenated hydrocarbons) was used for degreasing, which was banned because of its dangerous side effects. Instead, primarily aqueous emulsions are used today for degreasing aluminum. These may vary depending on the composition:

  • emulsifying (the fat is now in the emulsion)
  • demulsifying (the fat floats on top of the emulsion)

The decoction degreasing of aluminum

These products consist of water, salts and surfactants and require a certain temperature (around 50 to 95 degrees Celsius) for their effect. In addition, the solution can be adjusted strongly or slightly alkaline. To degrease aluminum, the solution must be slightly alkaline, or strongly alkaline for steel or stainless steel. This process for degreasing metals and thus also aluminum is concretely referred to as "Abkochentfettung".

Differences due to the composition

Depending on whether the solution is emulsifying or demulsifying, this entails different advantages and disadvantages, which must then be taken into account individually. If you want to use this process for degreasing aluminum, buy only the salt and surfactant mixture. Then this mixture is mixed according to manufacturer's instructions with water and heated accordingly. These products can also be purchased ready mixed.

Degrease and remove oxide layer

By this degreasing but not the removal of the oxidation layer is guaranteed. For this it is necessary to pickle the metal or aluminum accordingly. You also have to keep in mind that the oxidation layer on aluminum immediately forms again when the light metal is exposed to normal air.

Depending on the following processing also remove the oxide layer

As a result, paints do not adhere to the aluminum after painting or you get difficulties soldering aluminum (when soldering, the temperature remains around 500 degrees, but the oxide layer melts only at more than 2,000 degrees Celsius.

Tips & Tricks

You can also degrease the aluminum mechanically. To do this, brush or grind the aluminum. But again, there is the problem again that the oxidation layer immediately forms again.

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