BS 2X 35-2003.pdf

BRITISH STANDARD AEROSPACE SERIES BS 2X 35:2003 Selectively removable intermediate coating for aerospace purposes ICS 49.040 ? Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2X 35:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 October 2003 BSI 31 October 2003 First published April 1998 The following BSI references relate to the work on this British Standard: Committee reference ACE/44 Draft for comment 02/708991 DC ISBN 0 580 42747 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee ACE/44, Protective treatments and aircraft finishes, upon which the following bodies were represented: British Coatings Federation Ltd. Ministry of Defence Oil and Colour Chemists Association Society of British Aerospace Companies Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2X 35:2003 © BSI 31 October 2003 i Contents Page Committees responsibleInside front cover Forewordii 1Scope1 2Normative references1 3Definitions1 4Materials1 5Performance2 6Batch inspection5 7Marking5 Annex A (normative) Type approval6 Annex B (normative) Preparation of test panels6 Annex C (normative) Method for determination of ability to selectively remove7 Annex D (normative) Method for determination of ability to restore the paint scheme after selective removal7 Table 1 Tests on liquid paint: intermediate coating2 Table 2 Tests on liquid paint: paint scheme3 Table 3 Tests on the dry film3 List of references 9 Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2X 35:2003 ii© BSI 31 October 2003 Foreword This British Standard has been prepared by Technical Committee ACE/44 and is one of a series for paints and varnishes suitable for aerospace purposes. It specifies requirements for an intermediate paint coating used as part of a scheme including a primer and finish. It supersedes BS X 35:1998 which is withdrawn. This new edition of BS 2X 35 incorporates technical changes only. It does not reflect a full review or revision of the standard, which will be undertaken in due course. It has been assumed in the drafting of this British Standard that execution of its provisions is entrusted to appropriately qualified and experienced people. The quality assurance authority and approving authority referred to in this British Standard are as stated in the contract or order, or the accredited representative of the authority stated, as instructed by the purchaser. WARNING. This British Standard calls for the use of substances and/or procedures that may be injurious to health if adequate precautions are not taken. It refers only to technical suitability and does not absolve the user from legal obligations relating to health and safety at any stage. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 9 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2X 35:2003 © BSI 31 October 2003 1 1 Scope This British Standard specifies requirements for three types of intermediate coating, type A, type B and type C, which when incorporated in a paint scheme between primer and finish, allow selective removal of the finish using a defined paint remover. The paint scheme, including the intermediate coating, is intended for application to metallic and non-metallic surfaces for aerospace purposes, to provide equivalent protection against corrosion and mechanical damage, and resistance to aircraft fluids, to that provided by a paint scheme consisting of primer and finish alone. Type A intermediate coating is intended to function with a finish conforming to type A of the latest edition of BS X 34, where maximum resistance to fluid attack is required. Type B intermediate coating is intended to function with a finish conforming to type B of the latest edition of BS X 34, offering increased tolerance to flexing compared with type A finish. Type C intermediate coating is intended to function with a finish conforming to BS X 34 and DEF STAN 00-72 1 for the protection of military aircraft requiring resistance to chemical warfare agents and decontaminants. Annex A gives information on application for type approval. 2 Normative references This British Standard incorporates, by dated or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on page 9. For dated references, only the edition cited applies; any subsequent amendments to or revisions of the cited publication apply to this British Standard only when incorporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments. 3 Definitions For the purposes of this British Standard the definitions given in BS 2015 apply. 4 Materials 4.1 Composition NOTEThe composition of the intermediate coat is not defined. If a curing agent is included in the intermediate coating it shall be mixed in simple proportions by volume and thinned as necessary with the appropriate thinners as recommended by the manufacturer. 4.2 Scheme components 4.2.1 General Components used in tests on the intermediate coating as part of a paint scheme shall conform to 4.2.2, 4.2.3 and 4.2.4. If required, paint remover shall conform to 4.2.5. 4.2.2 Primer The primer shall conform to type B of the latest edition of BS X 33 unless otherwise specified. 4.2.3 Intermediate coating The intermediate coating shall conform to this British Standard. 4.2.4 Finish The finish shall conform to type A or type B of the latest edition of BS X 34 unless otherwise specified. 4.2.5 Paint remover The paint remover shall conform to the reference formulation specified in the latest edition of BS X 36 unless otherwise specified. NOTEThe performance of a scheme including components otherwise specified may be suitable but should be separately assessed. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2X 35:2003 2© BSI 31 October 2003 5 Performance 5.1 General 5.1.1 The test panels shall be prepared and coated as described in Annex B. 5.1.2 Unless otherwise specified, all tests shall be carried out in temperature and relative humidity conditions conforming to BS EN 23270. 5.2 Tests on liquid paint: intermediate coating The intermediate coating shall conform to Table 1. 5.3 Tests on liquid paint: paint scheme The paint scheme, comprising primer, intermediate coating and finish, prepared in accordance with Annex B, shall conform to Table 2. 5.4 Tests on the dry film: paint scheme The dry film of the paint scheme, comprising primer, intermediate coating and finish, prepared in accordance with Annex B, shall conform to Table 3. Table 1 Tests on liquid paint: intermediate coating TestTest panel, preparation and paint system ConditionsTest methodRequirement 1) ConditionComponents in their original or laboratory containers BS EN ISO 1513Shall be free from extraneous matter and shall show no skinning, gelling, hard settlement or other defect that may prevent satisfactory application of a defect-free film. 2) Volatile organic compound (VOC) content When prepared for application as specified in B.3.1 ASTM-D3960 2Shall be less than or equal to the reference value.a 3) Shelf lifeAfter 12 months at 5 °C to 35 °C, components in their original containers Tests 1), 5) and 6) of this table Shall conform to the requirements 4) Pot life4 h after preparation of a 200 ml sample as specified in B.3.1 BS EN ISO 2431Viscosity shall not increase by more than a factor of two from the initial value, unless otherwise specified by the purchaser. 5) ApplicationB.1.1 (300 mm × 100 mm test panel), B.1.3 and B.3 (without primer) 24 h after application Visual examination with normal corrected vision Paint film shall show an opaque even finish, free from runs, sags, wrinkling, pin-holing or other defect. 6) Drying timeB.1.1, B.1.3 and B.3 (without primer) After application BS EN 29117:1992 Paint film shall be through-dry at k6 h from application, unless otherwise specified by the purchaser. a The reference value shall be established during type approval unless agreed otherwise between manufacturer and purchaser (see Annex A). Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2X 35:2003 © BSI 31 October 2003 3 Table 2 Tests on liquid paint: paint scheme Table 3 Tests on the dry film TestTest panel, preparation and paint system ConditionsTest methodRequirement 1) Application B.1.1 (300 mm × 100 mm test panel), B.1.3 and B.4 24 h after application Visual examination with normal corrected vision Paint film shall show an opaque even finish, free from runs, sags, wrinkling, pin-holing or other defect. 2) Drying time B.1.1, B.1.3 and B.4After application BS EN 29117Paint film shall be through-dry at k6 h from application, unless otherwise specified by the purchaser. TestTest panel, preparation and paint system ConditionsTest methodRequirement 1) ColourB.1.1, B.1.3 and B.324 h after application, under diffuse daylight BS EN ISO 3668Shall match the colour specified by the purchaser. 2) Specular gloss B.1.1, B.1.3 and B.424 h after application, using a 60° glossmeter BS EN ISO 2813Shall be as follows: high gloss: 85 units or above; semi matt: (15 ± 3) units; matt: less than or equal to 5 units. 3) Flexibility (cupping test) B.1.1, B.1.3 and B.4BS EN ISO 1520 (×10 magnification) Type B: there shall be no cracking at an indentation depth of 4 mm. 4) Flexibility (impact) B.1.1, B.1.2 and B.4BS EN ISO 6272 (coating downwards) Type B: there shall be no cracking at an indentation depth of 3.8 mm. 5) Adhesion (crosshatch) B.1.1, B.1.3 and B.4BS EN ISO 2409, 1 mm spacing kclass 1 6) Hardness (scratch) B.1.1, B.1.3 and B.4BS EN ISO 1518There shall be no penetration of the needle to the intermediate coat under a load of 1 500 g. 7) Water resistance B.1.1, B.1.3 and B.4Immerse for 168 h at (40 ± 2) °C in water conforming to at least grade 3 of BS EN ISO 3696 a) Method 1, procedure A of BS EN ISO 2812-1 k2 min after removal shall show no blistering or other film defects. b) BS EN ISO 2409, 1 mm spacing k2 min after removal, the adhesion shall be kclass 1. c) BS EN ISO 1518k2 min after removal shall show no penetration of a needle to the intermediate coat under a load of 1 500 g. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2X 35:2003 © BSI 31 October 20034 Table 3 Tests on the dry film (continued) TestTest panel, preparation and paint system ConditionsTest methodRequirement 8) Fuel resistanceB.1.1, B.1.2 and B.4 Cut paint film through to substrate down the middle of panel; immerse at (40 ± 2) °C in NATO F-37 fluid for 1 000 h a) Method 1, procedure A of BS EN ISO 2812-1 Type C: k 2 min after removal shall show no blistering or other film defects. b) BS EN ISO 2409, 1 mm spacing Type C: k 2 min after removal, the adhesion shall be k class 1 9) Hydraulic fluid (phosphate ester) resistance B.1.1, B.1.2 and B.4 Cut paint film through to substrate down the middle of panel; immerse in tri-n-butylphosphate; type A: 1 000 h at (70 ± 2) °C; type B: 168 h at (70 ± 2) °C; type C: 336 h at (23 ± 2) °C; a) Method 1, procedure A of BS EN ISO 2812-1 k1 h after removal shall show no blistering or other film defects. b) BS EN ISO 1518; scratch (10 ± 2) mm parallel to cut k1 h after removal shall show no penetration of the needle to the intermediate coat under the following load: type A: 1 200 g; type B: 1 000 g; type C: 1 200 g. c) BS EN ISO 2409, 1 mm spacing Type C: k 2 min after removal, the adhesion shall be k class 1 10) Hydraulic fluid (hydrocarbon) resistance B.1.1, B.1.2 and B.4 Cut paint film through to substrate down the middle of panel; immerse at (70 ± 2) °C in NATO H-538 fluid for 300 h a) Method 1, procedure A of BS EN ISO 2812-1 Type C: k 1 h after removal shall show no blistering or other film defects. b) BS EN ISO 2409, 1 mm spacing Type C: k 2 min after removal, the adhesion shall be k class 1 11) Artificial weathering B.1.1, B.1.3 and B.4 BS EN ISO 11507, method A. Lamps: UV-B (313); total duration 500 h a) BS EN ISO 1520Type B: there shall be no cracking at an indentation depth of 4 mm. b) BS EN ISO 2813High gloss and semi matt: gloss reduction shall be k20 % of initial value. c) BS 3900-D8, BS 3900-D9 and BS 3900-D10 %E*abk 2.0 12) Selective removal B.1.1, B.1.2 and B.4 After 96 h at (70 ± 2) °C Annex CFinish or finish and intermediate coating shall be removable at k2 h without permanent damage to remaining coating. 13) Scheme restoration a) B.1.1, B.1.2 and B.4 BS EN ISO 11507, method A. Lamps: UV-B (313); total duration 500 h Annex CFinish or finish and intermediate coating shall be removable at k2 h without permanent damage to remaining coating. b) Annex DTests 1) and 2) of Table 2; tests 1) to 10) of this table Shall conform to the requirements. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 2X 35:2003 © BSI 31 October 2003 5 6 Batch inspection Before despatch, a representative sample of each batch of material, taken in accordance with BS EN ISO 15528, shall be tested to confirm conformity to tests 1, 4, 5 and 6 of Table 1, and, when prepared in accordance with Annex B, the scheme shall conform to tests 1, 2, 4 and 6 of Table 3. NOTESamples of material and material ingredients may be inspected at any stage of manufacture, and from any portion of the batch. 7 Marking In addition to any statutory requirements each container shall be legibly and durably marked with at least the following: a) a description of the material; b) the number and date of this British Standard, i.e. BS 2 X 35:2003; c) the type of material, i.e. type A, type B or type C; d) the colour (with the colour standard if appropriate); e) the manufacturers name and recognized trade mark; f) the batch number; g) the date of manufacture; h) mixing and thinning instructions. Licensed Copy: sheffieldun sheffieldun, na, Tue Nov 28 14:17:44 GMT+00:00 2006, Un