BS EN 927-3:2019
$167.15
Paints and varnishes. Coating materials and coating systems for exterior wood – Natural weathering test
| Published By | Publication Date | Number of Pages |
| BSI | 2019 | 36 |
This document specifies a natural weathering test for exterior wood coating systems mainly intended for decoration and protection of planed and sawn wood.
The test provides a means of evaluating the performance of a wood coating system during outdoor exposure. It forms the basis for the performance specification in accordance with ENÂ 927â??2. It also facilitates the comparison of coating systems performance on different substrates including the wood species, or other wood modifications.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | National foreword |
| 6 | 1 Scope 2 Normative references |
| 7 | 3 Terms and definitions 4 Principle |
| 8 | 5 Apparatus and materials 6 Coating sampling 7 Test panel selection 7.1 Wood reference species |
| 9 | 7.2 Preparation and selection of wood panels 7.2.1 Reference (standard) test panels |
| 10 | 7.2.2 Alternative test panels 7.3 Preparation of coated panels 7.3.1 Wood conditioning 7.3.2 Preparation of panels for the test coating 7.3.3 Preparation of panels for the Weathering Reference Material (WRM) 7.3.4 Sealing and ageing |
| 11 | 7.3.5 Thickness of the coating |
| 12 | 8 Procedure 8.1 General 8.2 Examination before exposure 8.3 Exposure 8.4 Examination after exposure 8.4.1 Examination on the exposure racks 8.4.2 Laboratory examination of unwashed panels |
| 13 | 8.4.3 Laboratory examination of washed panels 9 Precision data 10 Expression of results and test report |
| 14 | Annex A (normative)Details of test methods A.1 Gloss and change of gloss A.2 Colour and colour change A.3 Blistering A.4 Flaking A.5 Visual disfigurement by microorganisms (growth of fungi and algae) |
| 15 | A.6 Cracking A.7 Chalking A.8 General appearance A.9 Adhesion A.9.1 General A.9.2 Apparatus A.9.2.1 Cutting tool A.9.2.2 Adhesive tape A.9.3 Procedure A.10 Test for abnormally porous pine wood |
| 16 | A.11 Test for heartwood in pine |
| 17 | Annex B (normative)Assessment requirements for panels of test coatings and WRM |
| 18 | Annex C (informative)Example format for a test report |
| 21 | Annex D (informative)Optional tests including variations to standard weathering test procedure to obtain additional information on coating performance D.1 Principle D.2 Tests on alternative wood substrates D.3 Tests with water trap) D.3.1 Apparatus and materials |
| 22 | D.3.2 Preparation D.3.3 Panel assessment |
| 23 | D.4 Tests with back sealing of the panels |
| 24 | Annex E (informative)Explanatory notes E.1 Natural weathering test E.2 Validity of test reports E.2.1 System E.2.2 Climate and region |
| 25 | Annex F (informative)Precision data |
| 27 | Annex G (normative)Guidance on typical properties for some common wood species |
| 31 | Annex H (informative)Determination of adhesive strength of tape on test surface |
| 32 | Annex I (informative)Thermal or chemical modification to protect the wood I.1 General I.2 Thermally modified wood (TMT) |
| 33 | I.3 Chemically modified wood (CMT) |
