1.1Â This method is intended to determine whether anodic oxide coatings on aluminum and its alloys, that have undergone a sealing treatment and contact with an acid solution, are stainproof or nonadsorptive with respect to dyes.
1.2 Coatings that have been properly sealed should be proof against adsorption of coloring materials and, hence, “nonstaining” in many types of service.
1.3Â This method is applicable to anodic coatings intended for applications where they are exposed to the weather, or for protective purposes in corrosive media, and where resistance to staining is important.
1.4Â In the case of coatings colored in deep shades, where estimation of the intensity of any residual dye stain is difficult, interpretation of the test is based on whether or not the original color has been affected by the action of the test.
This specification covers measurement of strain resistance of anodic coatings on aluminium and its alloys, that have undergone a sealing treatment and contact with an acidic solution, are stainproof or nonadsorptive with respect to dyes. The method comprises contacting the test area of the anodized specimen with nitric acid solution and, after rinsing and drying, applying a special dye solution followed by rinsing and rubbing the test area with pumice powder, drying, and visual examination of the test area for retention of dye stain. Coatings that exhibit no dye stain or change in color are considered to have passed the test. Reagent grade chemicals shall be used in all tests. A specified solution of nitric acid shall be prepared in distilled or deionized water. A specified volume of aluminium blue 2WL dye shall be dissolved in distilled or deionized water.
| SDO | ASTM: ASTM International |
| Document Number | B136 |
| Publication Date | May 1, 2013 |
| Language | en - English |
| Page Count | 2 |
| Revision Level | 84(2013) |
| Supercedes | |
| Committee | B08.07 |