BS EN 4689:2021 pdf download.Aerospace series Paints and varnishes Two-components room temperature curing polyurethane finish High flexibility and chemical agent resistance for military application.
BS EN 4689 specifies the requirements for a two-components flexible polyurethane topcoat to be applied over EN 4687 and/or EN 4688 primers mainly for exterior aerospace applications.
The primer and the finish tested to this document will be from the same manufacturer applied in accordance with (i.a.w.) their instructions/Table 1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 2101, Aerospace series — Chromic acid anodizing of aluminium and wrought aluminium alloys
EN 2334, Aerospace series — Chromic-suiphuric acid pickle of aluminium and aluminium alloys
EN 2437, Aerospace series — Chromate conversion coatings (yellow) for aluminium and aluminium alloys
EN 3837, Aerospace series — Paints and varnishes — Nature and method for surface preparation of test
EN ISO 2811-2, Paints and varnishes — Determination of density — Part 2: Immersed body (plummet) method
EN ISO 2811-3, Paints and varnishes — Determination of density — Part 3: Oscillation method
EN ISO 2811-4, Paints and varnishes — Determination of density — Part 4: Pressure cup method
EN ISO 2812-1, Paints and varnishes — Determination of resistance to liquids — Part 1: Immersion in liquids other than water
EN ISO 28 12-2, Paints and varnishes — Determination of resistance to liquids — Part 2: Water immersion method
EN ISO 2813, Paints and varnishes — Determination of gloss value at 20°, 600 and 85°
EN ISO 3251, Paints, varnishes and plastics — Determination of non-volatile-matter content
EN ISO 3675, Crude petroleum and liquid petroleum products — Laboratory determination of density — Hydrometer method
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• ISO Online browsing platform: available at http://www.iso.org/obp
• IEC Electropedia: available at http://www.electropedia.org/
4 Surface pretreatments
In accordance with EN 3837, the surface pretreatments applicable to aluminium alloy test panels are the following:
EN 3837 — Procedure A: Sulfochromic pickling in accordance with EN 2334
EN 3837 — Procedure B: Chromate acid anodizing in accordance with EN 2101
EN 3837 — Procedure C: Chromate conversion coating in accordance with EN 2437
EN 3837 — Procedure D: Tartaric-Suiphuric-Acid anodizing in accordance with EN 4704.BS-EN-4689-2021