PRESENTATION FOR SURFACE PREPARATION METHOD FOR PAINTING
- 1. SURFACE PREPARATION METHOD FOR PAINTING – ABBAS V ABOOBACKER
- 2. AGENDA Introduction General points to remember Condition of the initial surface Influence of on-site environmental conditions Removal of contaminants Selection of the preparation grade
- 3. INTRODUCTION THE PERFORMANCE OF PROTECTIVE COATINGS OF PAINT AND RELATED PRODUCTS APPLIED TO STEEL IS SIGNIFICANTLY AFFECTED BY THE STATE OF THE STEEL SURFACE IMMEDIATELY PRIOR TO PAINTING. THE PRINCIPAL FACTORS THAT ARE KNOWN TO INFLUENCE THIS PERFORMANCE ARE — THE PRESENCE OF RUST AND MILL SCALE, — THE PRESENCE OF SURFACE CONTAMINANTS, INCLUDING SALTS, DUST, OILS AND GREASES, AND — THE SURFACE PROFILE. THE ISO 8501 SERIES, THE ISO 8502 SERIES AND THE ISO 8503 SERIES PROVIDE METHODS FOR ASSESSING THESE FACTORS, WHILE THE ISO 8504 SERIES PROVIDES GUIDANCE ON THE PREPARATION METHODS THAT ARE AVAILABLE FOR CLEANING STEEL SUBSTRATES, INDICATING THE CAPABILITIES OF EACH OF ATTAINING SPECIFIED LEVELS OF CLEANLINESS. THESE INTERNATIONAL STANDARDS DO NOT CONTAIN RECOMMENDATIONS FOR THE PROTECTIVE COATING SYSTEM TO BE APPLIED TO THE STEEL SURFACE. THEY DO NOT CONTAIN RECOMMENDATIONS ON SURFACE QUALITY REQUIREMENTS FOR SPECIFIC SITUATIONS EVEN THOUGH SURFACE QUALITY CAN HAVE A DIRECT INFLUENCE ON THE CHOICE OF PROTECTIVE COATING AND ON ITS PERFORMANCE. SUCH RECOMMENDATIONS ARE FOUND IN OTHER DOCUMENTS SUCH AS NATIONAL STANDARDS AND CODES OF PRACTICE. THESE INTERNATIONAL STANDARDS ARE USED TO ENSURE THAT THE SPECIFIED QUALITIES ARE — COMPATIBLE AND APPROPRIATE BOTH FOR THE ENVIRONMENTAL CONDITIONS TO WHICH THE STEEL WILL BE EXPOSED AND FOR THE PROTECTIVE COATING SYSTEM TO BE USED, AND — WITHIN THE CAPABILITY OF THE CLEANING PROCEDURE SPECIFIED. THIS DOCUMENT SHOULD BE READ IN CONJUNCTION WITH ISO 8504-2, ISO 8504-3 THAT DESCRIBE SPECIFIC SURFACE PREPARATION METHODS.
- 4. GENERAL POINTS TO REMEMBER THE PRIMARY OBJECTIVE OF SURFACE PREPARATION IS TO ENSURE THE REMOVAL OF DELETERIOUS MATTER AND TO OBTAIN A SURFACE THAT PERMITS SATISFACTORY ADHESION OF THE PRIMING PAINT TO THE STEEL. IT ALSO HELPS IN REDUCING THE AMOUNTS OF CONTAMINANTS THAT INITIATE CORROSION. THERE IS A VERY WIDE VARIATION IN THE CONDITION OF STEEL SURFACES REQUIRING CLEANING PRIOR TO PAINTING. THIS PARTICULARLY APPLIES TO MAINTENANCE OF AN ALREADY COATED STRUCTURE. THE AGE OF THE STRUCTURE AND ITS LOCATION, THE QUALITY OF THE PREVIOUS SURFACE, THE PERFORMANCE OF THE EXISTING COATING SYSTEM AND THE EXTENT OF BREAKDOWN, THE TYPE AND SEVERITY OF PREVIOUS AND FUTURE CORROSION ENVIRONMENTS, AND THE INTENDED NEW COATING SYSTEM ALL INFLUENCE THE AMOUNT OF PREPARATION REQUIRED.
- 5. PERSONNEL CARRYING OUT SURFACE PREPARATION WORK SHALL HAVE SUITABLE EQUIPMENT AND SUFFICIENT TECHNICAL KNOWLEDGE OF THE PROCESSES INVOLVED TO ENABLE THEM TO CARRY OUT THE WORK IN ACCORDANCE WITH THE REQUIRED SPECIFICATIONS. ALL RELEVANT MEASURES RELATED TO HEALTH AND SAFETY SHOULD BE TAKEN INTO ACCOUNT. IT IS RECOMMENDED THAT THE SURFACES TO BE TREATED BE READILY ACCESSIBLE AND SUFFICIENTLY ILLUMINATED. ALL SURFACE PREPARATION WORK SHALL BE PROPERLY SUPERVISED AND INSPECTED. IF THE SPECIFIED PREPARATION GRADE HAS NOT BEEN ACHIEVED BY THE PREPARATION METHOD SELECTED OR WHEN THE CONDITION OF THE PREPARED SURFACE HAS SUBSEQUENTLY CHANGED BEFORE THE APPLICATION OF THE COATING SYSTEM, RELEVANT PARTS OF THE PROCEDURE SHALL BE REPEATED SO AS TO OBTAIN THE SPECIFIED PREPARATION GRADE. DETAILS REGARDING THE PRELIMINARY TREATMENT OF WELDS, THE REMOVAL OF WELD SPATTER AND THE REMOVAL OF BURRS AND OTHER SHARP EDGES SHALL BE SPECIFIED. THESE MEASURES SHOULD BE TAKEN INTO ACCOUNT DURING THE MANUFACTURING PROCESS BEFORE THE SURFACE PREPARATION
- 6. ASSESSMENT OF THE SURFACE CONDITION AS THE COST OF SURFACE PREPARATION IS SIGNIFICANTLY INFLUENCED BY THE CONDITION OF THE INITIAL SURFACE, INFORMATION AS GIVEN IN A) ORB) BELOW SHOULD BE AVAILABLE BEFORE PARTICULAR SURFACE PREPARATION METHODS AND PREPARATION GRADES ARE SPECIFIED. THE RUST GRADE ASSESSED IN ACCORDANCE WITH ISO 8501-1 WILL DETERMINE WHICH REPRESENTATIVE PHOTOGRAPHIC EXAMPLE(S) SHALL BE USED IN ACCORDANCE WITH ISO 8501-1, ISO 8501-2 OR ISO 8501-4. A) FOR UNCOATED SURFACES — THE TYPE OF STEEL (INCLUDING SPECIAL TREATMENTS THAT INFLUENCE THE SURFACE PREPARATION) AND THE THICKNESS OF THE STEEL, — THE WORST RUST GRADE, ASSESSED IN ACCORDANCE WITH ISO 8501-1, THAT IS EVIDENT, TOGETHER WITH ANY RELEVANT SUPPLEMENTARY DETAILS (FOR EXAMPLE "RUST GRADE D WITH HEAVY RUST LAYERS"), AND — SUPPLEMENTARY DETAILS CONCERNING, FOR EXAMPLE, CHEMICAL AND/OR OTHER CONTAMINANTS SUCH AS WATER-SOLUBLE CORROSION-PROMOTING SALTS. B) FOR COATED SURFACES — THE TYPE (FOR EXAMPLE TYPE OF BINDER AND PIGMENT), APPROXIMATE FILM THICKNESS, CONDITION AND AGE OF THE COATING OR COATING SYSTEM, — THE DEGREE OF RUSTING ASSESSED IN ACCORDANCE WITH ISO 4628-3, TOGETHER WITH ANY RELEVANT SUPPLEMENTARY DETAILS ON APPARENT UNDER RUST, — THE DEGREE OF BLISTERING ASSESSED IN ACCORDANCE WITH ISO 4628-2, — THE DEGREE OF CRACKING ASSESSED IN ACCORDANCE WITH ISO 4628-4, — THE DEGREE OF FLAKING ASSESSED IN ACCORDANCE WITH ISO 4628-5, AND — SUPPLEMENTARY DETAILS CONCERNING, FOR EXAMPLE, ADHESION AND CHEMICAL AND/OR OTHER CONTAMINANTS. CONDITION OF THE INITIAL SURFACE
- 7. INFLUENCE OF ON-SITE ENVIRONMENTAL CONDITIONS IN ORDER TO HOLD DOWN THE COST OF SURFACE PREPARATION AND BECAUSE OF POSSIBLE SEVERE CONTAMINATION BY CORROSION-STIMULATING SUBSTANCES THAT ARE DIFFICULT TO REMOVE, STORAGE OF UNPROTECTED STEEL IN INDUSTRIAL OR MARINE ENVIRONMENTS SHOULD BE AVOIDED. AS FAR AS POSSIBLE, SURFACE PREPARATION SHOULD TAKE PLACE WHEN RUST GRADE A OR (OR RUST GRADE C FOR MANUAL PREPARATION) AS DEFINED BY ISO 8501-1 IS PRESENT, В FOLLOWED BY APPLICATION OF A SUITABLE PRIMER AS SOON AS POSSIBLE. NO SURFACE PREPARATION WORK USING DRY OR MOISTURE-INJECTION (SEE ISO 8504-2) BLAST-CLEANING METHODS OR OTHER DRY SURFACE PREPARATION METHODS SHOULD BE CARRIED OUT ON SITE DURING RAINFALL OR OTHER PRECIPITATION. TO MINIMIZE CONDENSATION ON THE SURFACE, THE TEMPERATURE OF THE SURFACE BEING PREPARED SHOULD BE HIGHER (USUALLY AT LEAST 3 ° HIGHER) THAN THE DEW POINT OF THE SURROUNDING AIR. IF THE WORK HAS С TO BE CONTINUED EVEN UNDER UNFAVOURABLE CONDITIONS, IT IS ESSENTIAL TO TAKE SPECIAL PRECAUTIONS SUCH AS WORKING UNDER A COVER, ENCLOSING IN A TENT, WARMING THE SURFACE AND/OR DRYING THE AIR (SEE ISO 8502-4). SURFACE PREPARATION WORK IN AREAS WHERE THERE IS A FIRE OR EXPLOSION HAZARD REQUIRES SPECIAL PRECAUTIONS (FOR EXAMPLE LOW-SPARK, ELECTRICAL-GROUNDING OR FLAME-FREE PROCEDURES).
- 8. REMOVAL OF CONTAMINANTS OIL, GREASE, DIRT AND SIMILAR CONTAMINANTS SHALL BE REMOVED PRIOR TO SURFACE PREPARATION USING THE SELECTED METHOD. IN ADDITION, PRIOR REMOVAL OF HEAVY, FIRMLY ADHERING RUST AND MILL SCALE BY SUITABLE MANUAL OR MECHANICAL TECHNIQUES CAN BE NECESSARY. IF SPECIFIED OR AGREED BY INTERESTED PARTIES, WATER-SOLUBLE CONTAMINANTS, E.G. SALT, SHALL BE REMOVED, USING OTHER TECHNIQUES, PRIOR TO AND/OR AFTER APPLICATION OF THE SELECTED SURFACE PREPARATION METHOD. SUITABLE METHODS FOR REMOVAL OF CONTAMINANTS ARE DESCRIBED IN ISO 12944-4. SELECTION OF THE SURFACE PREPARATION METHOD THE SELECTION OF THE METHOD FOR THE PREPARATION OF A GIVEN SURFACE WILL DEPEND ON — THE SURFACE CONDITION (SEE CLAUSE 5. THE ISO 8502 SERIES AND THE ISO 8503 SERIES), — PRACTICABILITY (FOR EXAMPLE OPERATING CONDITIONS, TARGET DATES, AND HEALTH, SAFETY AND ENVIRONMENTAL CONSIDERATIONS SUCH AS EVOLUTION OF DUST, REDUCTION OF WASTE BY CHOICE OF SUITABLE BLAST-CLEANING ABRASIVES, AMOUNT OF WATER REQUIRED AND FLAME APPLICATION), — WHETHER THE COMPLETE SURFACE OR ONLY PARTS OF IT ARE TO BE PREPARED, — THE SPECIFIED OR REQUIRED PREPARATION GRADE, — THE COATING SYSTEM, — ECONOMIC CONSIDERATIONS, AND — PARTICULAR REQUIREMENTS WITH REGARD TO OPERATING CONDITIONS OR THE REQUIRED RESULT OF THE SURFACE PREPARATION PROCEDURE (FOR EXAMPLE SURFACE PROFILE OR REMOVAL OF WATER-SOLUBLE CONTAMINANTS).
- 9. SELECTION OF THE PREPARATION GRADE The selection of the preparation grade for a given surface will depend on — the surface condition (see Clause 5. the ISO 8502 series and the ISO 8503 series), — the coating system, — the corrosivity of the environment to which the coated surface will be exposed, — whether the complete surface or only parts of it are to be prepared, — the practicability of the surface preparation method associated with the preparation grade, and — economic considerations.
- 10. SELECTION OF THE PREPARATION GRADE Usually, the preparation grades specified in ISO 8501-1 and ISO 8501-2 are used. Other preparation grades (such as ISO 8501-4), defined either by special reference specimens or by reference areas that are part of the object to be treated, can be used by agreement between the interested parties. If reference areas are agreed, these should be either effectively protected against change or photographed.
- 11. ASSESSMENT The appearance of the prepared surface depends on — the condition of the surface prior to treatment, — the type of substrate, and — the surface preparation method, including the tool or material used. After the surface preparation procedure (cleaning as specified), the prepared surfaces shall be assessed as described in ISO 8501-1, ISO 8501-2 or ISO 8501-4, i.e. the cleanliness is assessed by evaluating the appearance of the surface only. If specified or agreed, the surfaces shall additionally be assessed in accordance with the ISO 8502 series and the ISO 8503 series.
- 12. THANK YOU Abbas V Aboobacker abbasvaisyamveettilaboobacker@gmail.co m