1、BRITISH STANDARD BS 6949:1991 Incorporating Amendment No. 1 Specification for Bitumen-based coatings for cold application, excluding use in contact with potable waterBS6949:1991 This British Standard, having been prepared under the directionof the Pigments, Paintsand Varnishes StandardsPolicy Commit
2、tee, waspublished under the authorityof the Standards Boardand comes into effect on 31October 1991 BSI 06-1999 First published December 1988 Second edition October 1991 The following BSI references relate to the work on this standard: Committee reference PVC/27 Draft for comment 91/51891 DC ISBN 0 5
3、80 20005 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Pigments, Paints and Varnishes Standards Policy Committee (PVC/-) to Technical Committee PVC/27, upon which the following bodies were represented: Aluminium Federation Aluminium
4、Finishing Association Aluminium Window Association British Railways Board British Telecommunications plc Consumer Policy Committee of BSI Department of the Environment (Building Research Establishment) European Resin Manufacturers Association Institute of Corrosion Institute of Metal Finishing Insti
5、tution of Structural Engineers Institution of Water and Environmental Management (IWEM) London Regional Transport Metcom Ministry of Defence National Federation of Painting and Decorating Contractors Oil and Colour Chemists Association Paint Research Association Paintmakers Association of Great Brit
6、ain Ltd. Society of Chemical Industry Steel Window Association Union of Construction, Allied Trades and Technicians Zinc Development Association Amendments issued since publication Amd. No. Date Comments 7287 September 1992 Indicated by a sideline in the marginBS6949:1991 BSI 06-1999 i Contents Page
7、 Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Classification 1 4 Sampling 1 5 Flash point 1 6 Drying and over-coating times 1 7 Finish 1 8 Protection against corrosion 2 9 Bend resistance 2 10 Shelf life 2 11 Marking 2 Appendix A Guidance on the use of bitumen-ba
8、sed coatings for cold application 3 Appendix B Methods of test for performance requirements 4 Appendix C Preparation and coating of test panels 5 Publication(s) referred to Inside back coverBS6949:1991 ii BSI 06-1999 Foreword This British Standard was prepared under the direction of the Pigments, Pa
9、ints and Varnishes Standards Policy Committee. It supersedes BS 6949:1988, which is withdrawn. This edition introduces technical changes but it does not reflect a full review or revision of the standard, which will be undertaken in due course. The main technical changes are: a) introduction of separ
10、ate immersion periods for type 1 and type 2 materials; b) a change in the size of the panel used in the methods of test for protection against corrosion (see B.4). NOTEDifferences in the text between this edition and BS 6949:1988 are indicated by a line in themargin. This British Standard contains r
11、equirements for bitumen-based coatings unsuitable for use in contact with potable water. Attention is drawn to BS 3416:1991 which covers only bitumen-based coatings suitable for use in contact with potable water and for approval by the UK Water Fittings Byelaws Scheme administered by the Water Resea
12、rch Centre. This British Standard also takes account of recent developments in this type of paint enabling the use of mineral fillers and alternative solvents. Two types of bitumen-based coating are included, each type having three classes relating to the solvent system used for the coating. For gui
13、dance on the use of these materials reference should be made to Appendix A, and to BS 5493 and BS 6150. Product certification. Users of this British Standard are advised to consider the desirability of third party certification of product conformity with this British Standard based on testing and co
14、ntinuing surveillance, which may be coupled with assessment of a suppliers quality systems against the appropriate Part of BS 5750. Enquiries as to the availability of third party certification schemes will be forwarded by BSI to the Association of Certification Bodies. If a third party certificatio
15、n scheme does not already exist, users should consider approaching an appropriate body from the list of Association members. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance
16、 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, pages1 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had
17、amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS6949:1991 BSI 06-1999 1 1 Scope This British Standard specifies performance and marking requirements for a range of bitumen-based, solvent-borne coatings. It covers coatings for cold application by eit
18、her brushing, spraying, rolling or dipping processes intended to give a coat for the corrosion protection and waterproofing of substrates including iron and steel. Two types, each with three classes, are included. All of these are suitable only for applications where the coating will not be in conta
19、ct with potable water (seeBS 3416). The level of gloss of the finished film is not specified in this British Standard. NOTE 1These bitumen coatings, are neither intended to withstand hot conditions, as on boilers, smoke stacks, etc., for which special coatings should be obtained, nor to resist conta
20、mination with mineral oils or paint solvents, all of which conditions will cause softening of the film. NOTE 2Guidance on the use of bitumen-based coatings is given in Appendix A, BS 5493 and BS 6150. NOTE 3The titles of the publications referred to in this standard are listed on the inside back cov
21、er. 2 Definitions For the purposes of this British Standard, the definitions given in BS 2015 apply together with the following. 2.1 bitumen a viscous liquid, or a solid, consisting essentially of hydrocarbons and their derivatives, which is soluble in trichloroethylene and is substantially non-vola
22、tile and softens gradually when heated. It is black or brown in colour and possesses waterproofing and adhesive properties. It is obtained by refinery processes from petroleum, and is also found as a natural deposit or as a component of naturally occurring asphalt in which it is associated with mine
23、ral matter NOTEThe international definition of bitumen relates its solubility to carbon disulphide but, in the United Kingdom, the safer material trichoroethylene is used as the test solvent as examination has shown no significant difference. 2.2 bitumen-based coating a liquid mixture of bitumen in
24、a carrier (solvent or solvent mixture), usually paraffinic hydrocarbons, chlorinated hydrocarbons and aromatic hydrocarbons, with or without fillers, to give a consistency suitable for brushing, spraying, rolling or dipping in accordance with the recommendations of the manufacturer. The coating may
25、exhibit thixotropy 3 Classification 3.1 Bitumen-based coatings shall be classified into two types. a) Type 1, without fillers. b) Type 2, with fillers. 3.2 Each type shall be further sub-classified as follows. a) Class A, using white spirit complying with BS245 as the carrier. b) Class B, using eith
26、er a solvent other than white spirit, or a solvent mixture with a flash point of or above 21 C and below 32 C as the carrier. c) Class C, using either a solvent other than white spirit, or a solvent mixture with a flash point of or above 32 C as the carrier. 4 Sampling Take and store in accordance w
27、ith BS 3900-A1 representative samples of not less than 1 000 mL of the coating either at the filling stage or from one or more previously unopened containers. Condition the samples for at least 12 h at 23 2 C before carrying out any tests. 5 Flash point When tested in accordance with B.1, coatings s
28、hall comply with the following requirements. a) Coatings of classes A and C shall not flash at a temperature below 32 C. b) Coatings of class B shall not flash at a temperature below 21 C. 6 Drying and over-coating times 6.1 Surface-dry time When tested in accordance with B.2.1, films of coatings sh
29、all be surface dry: a) if type 1, in not more than 4 h; b) if type 2, in not more than 8 h. 6.2 Over-coating time When tested in accordance with B.2.2, the film shall show no cissing, crawling, sinking, lifting or wrinkling during application or after 24 h drying time. 7 Finish When tested in accord
30、ance with B.3, the film shall be smooth, opaque and free from sags or runs or other surface imperfections.BS6949:1991 2 BSI 06-1999 8 Protection against corrosion 8.1 Resistance to tap water immersion 8.1.1 When tested in accordance with B.4.1.1, the film shall remain completely adherent to the subs
31、trate. Any blistering shall not exceed rating2(S3) in accordance with BS 3900-H2. 8.1.2 When tested in accordance with B.4.1.2, the surface of exposed metal revealed shall show no visible rust or pitting. 8.2 Resistance to artificial sea water immersion 8.2.1 When tested in accordance with B.4.2.1,
32、the film shall show no signs of breakdown. Any blistering shall not exceed rating 2 (S3) in accordance with BS 3900-H2. 8.2.2 When tested in accordance with B.4.2.2, the surface of exposed metal revealed shall show no visible rust or pitting. 9 Bend resistance When tested in accordance with B.5, the
33、 film shall show no signs of cracking or of becoming detached from the substrate. 10 Shelf life The product, if stored in unopened containers for12months at a temperature not exceeding 30 C shall meet the requirements of clauses 5 to 9. No separation shall take place which cannot be removed by stirr
34、ing. NOTEIn the case of thixotropic coatings, sufficient time, as advised by the manufacturer, should be allowed after any stirring to redevelop the thixotropy. 11 Marking Each container of bitumen-based coating shall be clearly labelled with the following information: a) the manufacturers identific
35、ation; b) the number of this British Standard and the appropriate type and class of the product, e.g.BS6949:1991 1) , type 1, class A; c) the nominal content by mass or volume; d) the batch number from which the container was filled; e) the month and year in which the batch was manufactured; f) a st
36、atement that it is unsuitable for use in contact with potable water; g) whether the coating is suitable for brushing, spraying, rolling or dipping. 1) Marking BS 6949:1991 on or in relation to a product represents a manufacturers declaration of conformity, i.e. a claim by or on behalf of the manufac
37、turer that the product meets the requirements of the standard. The accuracy of such a claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirable.BS6949:1991 BSI 06-199
38、9 3 Appendix A Guidance on the use of bitumen-based coatings for cold application A.1 Safety instructions Consult the safety instructions of the manufacturer before application and, especially, before spraying these materials. NOTEAttention is drawn to the Health and Safety Executive Guidance Note G
39、S5 “Entry into Confined Spaces” regarding the safe working in confined spaces. A.2 General properties Like some other protective coatings referred to in BS 5493 and BS 6150, bitumen coatings are used to protect surfaces rather than to decorate them, their function being to exclude moisture or other
40、corrosive agents. It is thus important that each coat is applied in a continuous manner, without holidays or “misses”. Bitumen coatings have little power to inhibit corrosion. Hence, if ferrous surfaces are not adequately cleaned to be free from rust and mill-scale before these coatings are applied,
41、 under-rusting may occur with consequent failure of the film. They have good adhesion to most surfaces commonly found in building, e.g. ferrous metals, slightly etched galvanized iron and steel, concrete and brick, and will withstand moderate concentrations of acids and alkalis. These bitumen coatin
42、gs are neither intended to withstand hot conditions, as on boilers, smoke stacks, etc., for which special coatings should be obtained, nor to resist contamination with mineral oils or paint solvents, all of which conditions will cause softening of the film. A.3 Precautions Provide adequate ventilati
43、on, particularly of closed vessels, while the material is being applied and until it is thoroughly dry. The use of air-fed masks for personal ventilation is recommended. When painting the interiors of tanks, use a forced air supply to disperse the solvent and prevent residual solvent condensing on t
44、he coating and washing it off. Avoid naked lights in or near the tanks or cisterns during these periods. Use appropriate barrier creams and protective clothing to prevent skin sensitization. Skin should be thoroughly washed and clothing removed and cleaned as soon as possible after the work has been
45、 completed. A.4 Durability The durability of bitumen coatings depends mainly upon a) the thickness of the film and b) the degree of exposure. It is important to apply the products liberally in a number of coats, as thick films give proportionately greater protection than thin ones, and to ensure tha
46、t all areas of a surface are covered. The degree of exposure largely controls the rate of deterioration of the film surface. Bitumen is sensitive to sunlight and other strong light, which quickly cause complete loss of gloss, followed later by a form of chalking. This is, however, confined to the su
47、rface and provided that the film is of adequate thickness it will continue to give protection. In situations protected from such attack, the gloss is maintained longer. Crazing sometimes occurs with bitumen coatings but bitumen-coated ferrous metals are seldom subject to early corrosion from this ca
48、use. A.5 Thinning Where thinning is necessary, e.g. as a first coat on very porous surfaces, only white spirit should be used in the case of class A coatings. For class B andC coatings, only the manufacturers recommended thinners should be used. In all cases thinning should be kept to a minimum for
49、the type of use required. A.6 Primer In order to prevent under-rusting on ferrous metals, a system of rust-inhibiting primer and bitumen coating is often advocated. Reference should be made to the bitumen-coating manufacturer. It is important to allow adequate time for the hardening of primers prior to the application of bitumen-based coatings. A.7 Preparation of surfaces Establish that the substrate and the bitumen-based coating are compatible and prepare the substrate according to its type as follows. a) Bare non-porous surfaces. All dirt, including loosely adheri
