Acid Etching for Aluminum & Alloys Prior to Chemical Conversion Coating or Plating Processes
Liquid, immersion or spray applications is a blend of acids for use in the etching/deoxidizing alloys of aluminum prior to application of conversion coating or anodizing processing. Works synergistically with ALUMAL DEOX 425 to improve removal of surface smuts, which is defined by Qualicoat requirements.
Features & Benefits
- Works very well on all alloys but especially those containing high magnesium and silicon.
- One component liquid for ease of make up and replenishment
- Immersion or spray (cascade) application.
- No Nitrates or Phosphates
- Removes oxide layers often obtained after prolonged exposures of metal to humid environments with minimal grain boundary attack on most aluminum alloys.
This process belongs toALUMAL DEOX series
Aluminum has a natural protective oxide surface film and affinity for oxygen, in order to improve the appearance of an aluminum part or component through conversion coating, painting, anodizing or plating processes, requires some additional surface treatment processing to remove the natural oxide layer.
Once aluminum and alloys are exposed to etching solutions, the oxides are often removed but then depending on the alloy of aluminum, there are surface adherent non-reactive reaction products referred to as “smuts” on their surfaces. Desmut formulations are required to remove these from the surfaces of aluminum parts or components. The types of smuts present are related to the alloy of aluminum. For example, 200 series wrought aluminum have resulting copper smuts that are effectively removed by iron based desmut formulations. Alloys containing silicon or magnesium smuts are thoroughly desmutted with blends of acids including fluorides, nitrates & sulphates. All surface smuts must be removed for success with applications of conversion coatings, painting, anodizing or plating aluminum and alloys.
Choices for Anodizing applications include ALUMAL DEOX 411, 436 or 444.
For chemical conversion coating prior to painting, review ALUMAL DEOX 411, 425, 445, or 427.
Coventya offers many additional types of ALUMAL products to effectively deoxidize and desmut all types of cast and wrought alloys of Aluminum. This is just a partial list of what is available; contact your local COVENTYA representative for review of other available technologies.