1 Scope

This document specifies two methods to assess the quality of sealed anodic oxidation coatings on aluminium and its alloys:

• Method 1 which assesses the quality of sealed anodic oxidation coatings by measuring the loss of mass after immersion in a phosphoric acid based solution without prior acid treatment;

• Method 2 which assesses the quality of sealed anodic oxidation coatings by measuring the loss of mass after immersion in a phosphoric acid based solution with prior acid treatment.

Method 1 is applicable to anodic oxidation coatings intended for decorative or protective purposes or where resistance to staining is important.

Method 2 is applicable to anodic oxidation coatings intended for outdoor architectural purposes. For less severe applications, Method 1 can be more suitable.

The methods are not applicable to the following:

• hard-type anodic oxidation coatings which normally are not sealed;

• anodic oxidation coatings that have been sealed only in dichromate solutions;

• anodic oxidation coatings produced in chromic acid solutions;

• anodic oxidation coatings that have undergone treatment to render them hydrophobic.