Alumimium Chromate Conversion
CPK offer large capacity acid dip and chromate conversion for aluminium etching prior to finishing. Items upto 7m long, 1m high and 0.9m wide can be treated. The treatment is a 5 stage process as detailed below:

• Acid Dip
• Rinse
• Chromate Conversion
• 1st Rinse
• 2nd Rinse.

Aluminium Treatment
Because most coatings do not adhere particularly well to aluminium, for long term coating performance a chromate conversion is recommended. The conversion process, like anodising, converts the surface of aluminium to a more stable and coating friendly state. Because the conversion layer is integral to the component the applied coating is less likely to peel when subject to deformation or weathering. Our five part treatment process starts off with an acid based degreaser that removes surface contaminants including oxide layers from the aluminium surface, leaving the component ready, after a rinse, for the chromate conversion which conforms to BS6496.

Coating Weight
The weight of a chromate conversion is about 1.3g/m², (about 2µm thick).