Dr M Raouf Kattan FRINA C.Eng IMAREST/RINA091 Implementing The Paint Specification in the Performance Standard for Protective Coatings – The Challenge The North East Coast Joint Branch of IMAREST and RINA Newcastle upon Tyne 12 March 2009

Objective To provide a review of the requirements/challenges posed by the IMO PSPC and highlight some key issues.

Rust is a Must – a poem …….All the ships upon the sea Slowly turn to Fe 2 0 3……. T.B Watson

High Technology shipbuilding

Surface preparation

Painting Improvement is needed

The Parties Involved at present Productivity/ Environment ShipyardShip-owner Performance Coating supplier

The Parties Involved A paint specification is in many ways a compromise: –It has to meet with the yards building procedures, environmental and productivity requirements –The shipyard is the customer of the coating manufacturers and they have to be competitive on standards as well as price –It has to match the paint suppliers product range. The PSPC is in effect making the compromise redundant

Coating Performance Standard Review The Performance Standard for Protective Coatings (PSPC) provides the technical requirements for protective coatings in dedicated sea water ballast tanks of all types of ships of 500 gt and greater and double sided skin spaces on bulk carriers of 150m and greater in length. It will be mandatory and is intended to be included as amendments to SOLAS regs II-1/3-2 and XII/6 It is also recommended to be applied where possible to items, not integral to the structure e.g. ladders, platforms – Permanent means of access

Tip of the iceberg A family of regulations –PSPC –Permanent means of access –Cargo tanks –Maintenance These will change the current compromise solutions

SOLAS Regulation All vessels now cannot be delivered without a compliant ballast tank coating systems For Common Structural Rule vessels – this now becomes a condition of class!

Why? Structural failures Chase for minimum standards Use of high tensile steels Paint as part of the solution – but was it part of the problem?

Coating Performance Standard Review Aims of the PSPC –to provide a 15 year life for ballast tank coatings over which it is defined as in being ‘good’ condition. –‘Good’ condition is defined in resolution A.744(18) and is “ condition with only minor rust spotting” –Better coating systems with reduced maintenance –Improved safety at sea

Coating Performance Standard Review Aims of the PSPC

Coating Performance Standard Review Aims of the PSPC

Coating Performance Standard Review Entry into force The proposals will apply to the aforementioned types of vessels: –For which the building contract is placed on or after 1st July 2008, or –In the absence of a building contract, the keels of which are laid or which are at a similar stage of construction on or after 1st January 2009, or –The delivery of which is on or after 1st July 2012

Coating Performance Standard Review Entry into force However IACS applied the proposals on ratification to tankers ( L > 150m) and bulkers (L > 90m) under the Common Structural Rules (CSR) for contracts signed from December 8 th 2006 The first new building classed under the above rules were delivered in the second half of 2008

The Parties Involved Productivity Performance ShipyardShip-owner ? Coating supplier Classification Soc.

Coating Performance Standard Review Main Elements of the PSPC: –Design of a specification and coating system –Coating System approval –Definition of inspection procedures –Production of a Coating Technical File (CTF) which records all aspects of the process –Verification of compliance

The Paint Specification The paint specification is at the heart of the PSPC and covers: –Primary and Secondary surface preparation standards –Steel profile range –Cleanliness of surfaces prior to coating –Soluble salt limits –Steel condition –Thickness and number of coats –Environmental conditions allowed

The Paint Specification The paint specification applies to the coating system that has been selected Selection of the coating system takes into account the service conditions and planned maintenance All coatings to be epoxy based or equivalent and consist of multi-coat systems of contrasting colour The top coat to be a light colour

Type approval All coatings to be pre-qualified by: –A method corresponding to a specified test procedure or equivalent ( now Annex 1), cross test with shop primer or… –Documented field exposure with a final condition of “GOOD” after 5 years Non Annex 1 test must show equivalent testing procedures and needs. A Statement of Compliance or Type Approval Certificate to be issued by a third party - independent of the coating manufacturer

Inspection process The inspection process covers all the processes and defines the standards from: Shop Primer Application Block Painting Post Erection Repairs

The inspection process The inspection processat each stage can be separated into the following simple processes: –Cleaning the surface –Preparing the surface –Coating the surface

The Paint Specification The paint specification covers all the processes and defines the standards from : Shop Primer Application Block Painting Post Erection Repairs

The Paint Specification Shop Primer –Four items are defined The standard of surface preparation of the bare steel - determines ‘cleanliness’ The ‘profile’ of the steel - determines adhesion The maximum level of water soluble salts on the surface prior to application - determines resistance to blistering The shop primer type (the thickness of shop primer is not specified but will be given on the product technical data sheet)

The Paint Specification Shop Primer –The standard of surface preparation of the bare steel ex the steel mill is to be Sa2½ as defined in ISO –This process is carried out in an automated plant using, typically, round steel shot –Achieving this standard on a well maintained plant is normally not a problem

The Paint Specification Shop Primer –Sa2½ as defined in ISO is “When viewed without magnification, the surface shall be free from visible oil, grease and dirt, and from mill scale, rust, paint coatings and foreign matter. Any remaining traces of contamination shall show only as slight stains in the form of spots or stripes “ All the standards have pictorial references

The Paint Specification Shop Primer –Surface profile to be between microns and its measurement is defined in the standard ISO /3 –The measurement is by a comparator of known roughness and size

The Paint Specification Shop Primer –Water Soluble Limit on the surface prior to coating to be less than or equal to 50 mg/m² ( or 5µg/cm²) –This is measured by a conductivity method according to ISO A known volume of water is used to extract any soluble material from a known area and the conductivity of that solution is measured and converted to a mg/m²

The Paint Specification Shop Primer –Shop Primer is to be a zinc containing inhibitor free zinc silicate or equivalent (its compatibility with the main coating system to be confirmed by the coating manufacturer ) –The vast majority of shop primers in use today meet this criteria

The Paint Specification Shop Primer –There is also statement stating that blasting should not be carried out when: The relative humidity is > 85% The surface temperature of the steel is < 3°C (5 °F) above the dew point

The Paint Specification Shop Primer –The application of shop primer is a carried out in an enclosed automated plant and is a continuous process. –Usually once the plant is set up it is left to run with only spot checks being made –There is no specific mention of any of the shop primer details being required for the CTF …but ‘records of the coating application’ are requested

The Paint Specification Shop Primer Also –Depending on ship type as little as 5% of shop primed steel will be in the ballast tanks –In most cases only one side of the plate will be part of the ballast tank surface –Pre-primed plate sourced externally will be subject to the same requirements

The Paint Specification Shop Primer –It is probable given the practical difficulties outlined of measuring the parameters etc. stated in the PSPC that a procedure for maintaining the standards ( i.e. spot checks) in the shop primer plant will have to be produced, audited and certified

The Paint Specification The paint specification covers all the processes and defines the standards from: Shop Primer Application Block Painting Post Erection Repairs

The Paint Specification Block painting is the application of the main coating system. In some yards the coating of ballast tanks is carried out in-situ - after erection - but the vast majority of new building yards coat the ballast tanks at the ‘block stage’

The Paint Specification The specification at block stage covers: –The condition of the actual steel work –Surface preparation and profile requirements –Thickness of the coating and number of coats –Stripe coats –Cleanliness/contamination –Soluble salt levels –Environmental conditions

The Paint Specification The specification at block stage covers: –The condition of the actual steel work - to prevent premature breakdown of the coating system –Surface preparation and profile requirements - determines coating life and adhesion –Thickness of the coating and number of coats - determines protective properties –Stripe coats - to prevent premature breakdown –Cleanliness/contamination - to prevent premature breakdown

The Paint Specification The specification at block stage covers: –Soluble salt levels - to prevent blistering –Environmental conditions - to prevent premature breakdown

The Paint Specification Block stage : –The steelwork should be prepared so that the coating can be applied evenly in accordance with ISO grade P2 –This involves removing sharp edges, weld spatter etc - most coatings flow away from sharp edges leaving an inadequate thickness for protection –Edges of stiffeners are also to be rounded to a radius of 2mm - or subject to ‘three pass grinding’ or equivalent

The Paint Specification Block stage : –ISO grade P2 consists of a number of illustrations that are provided covering imperfections such as weld spatter, slag, flame cut edges etc and P2 grade describes the preparation on each imperfection

The Paint Specification Block stage : –E.g. P2 for weld porosity: “ Surface pores shall be sufficiently open to allow penetration of paint, or dressed out” P1 - “as welded”. P3 - “ surface shall be free from visible pores”

The Paint Specification Block stage : –Surface Preparation is defined as per the shop primer specification -i.e in accordance with ISO –As the steel is already coated with shop primer the specification calls for: Sa2½ standard of preparation on welds and damaged shop primer “Sa2 standard removing at least 70% of intact shop primer” if the shop primer has not passed a pre- qualification test”

The Paint Specification Block stage : –“Sa2 removing at least 70% of intact shop primer” is not a standard –Sa2 refers to bare steel –Is it 70% removal by area or volume?? If the shop primer has passed a pre-qualification test as part of the epoxy system it may remain but should be cleaned by sweep blasting, high pressure washing or equivalent A number of yards sweep blast the shop primer anyway when preparing the welds as it is quicker and more productive

The Paint Specification Block stage : –Steel Profile is specified as microns or that recommended by the coating manufacturer and is according to ISO /3 as per the shop primer specification

The Paint Specification Block stage : –Paint thickness and number of coats are specified as follows: Nominal dft microns in total This is to be achieved in a minimum of 2 coats and 2 stripe coats Typical specs will be 2 x 160 microns – but coats of differing thicknesses are allowed –Stripe coats by brush or roller to be applied to edges, welds, etc (roller to be used for scallops and rat holes only) –Second stripe coat may be omitted on welds if the ndft can be met by the coats applied

The Paint Specification Block stage : –The paint thickness specification has upper and lower limits: NDFT of 320 microns but with a “90/10” rule At least 90% of all thickness measurements will be greater or equal to the NDFT and none of the remaining percentage (up to10%) to be below 0.9 of the NDFT i.e. a minimum thickness of 288 microns Upper limit to be defined by the coating manufacturer

The Paint Specification Block stage : –The PSPC also advises on where to check for dft and the number of readings to be taken (This is in annex 3 and is referenced in the standard SSPC - PA2 – this covers calibration, etc) –Thickness measurements are to be taken after each coat for quality control purposes and the total dft confirmed on completion

The Paint Specification Block stage : –The PSPC also advises on where to check for dft and the number of readings to be taken (This is in annex 3 and is referenced in the standard SSPC - PA2 – this covers calibration, etc) –Thickness measurements are to be taken after each coat for quality control purposes and the total dft confirmed on completion

The Paint Specification Block stage : –Cleanliness and contamination on a surface prior to coating are defined in the specification as: no oil or other visible contamination to be present on the surface Dust quantity rating “1” for dust size class 3,4 or 5 as stated in ISO Lower particle sizes to be removed if visible without magnification –Any particles embedded in a coating are also to be removed

The Paint Specification Block stage : –ISO uses clear adhesive tape that is pressed onto a surface and after removal is placed on a ‘display board’ of contrasting colour to the dust. The tape is then compared against standards – 1 ( minimum ) to 5 (maximum) for volume of dust –The dust is also classified by size : Class 0 particles (not visible under 10x magnification) and class 5 ( particles clearly visible in normal vision of up to 5 mm in diameter.)

The Paint Specification Block stage : –Soluble salt levels on the steel after surface preparation but before painting are specified to be less than or equal to 50 mg/m². –This is to be measured according to ISO as per shop primer application and in at least one location per block

The Paint Specification Block stage : –The environmental conditions under which the coating may be applied are to be in accordance with the manufacturer’s recommendations but the specification states that coatings shall not be applied: If the relative humidity is > 85% or The surface temperature is < 3ºC ( 5 ºF) above the dew point

The Paint Specification Block stage : –Other parameters such as the drying, curing and over coating times are to be given by the manufacturer and will be found on the data sheet –The method of application will also be specified by the manufacturer as will any repairs of defective areas –Appropriate ventilation is also required as recommended the manufacturer

The Paint Specification The paint specification covers all the processes and defines the standards from: Shop Primer Application Block Painting Post Erection Repairs

The Paint Specification Post Erection surface preparation and repairs are specified as follows: –Butts (‘join ups’) to be prepared prior to coating to ‘St3 or better or Sa2½ where practical’ as per ISO

The Paint Specification Small damages - up to 2% of the total area are to be prepared to St3 standard prior to coating. Contiguous damage over 25 m² or over 2% of the total area of the tank should be prepared to Sa2½ (note that open blasting in a confined space can lead to over-blast damage) All coating repairs to be feathered in the overlap Note: There is no profile requirement in St3 standard – this may be an issue!!

Coating technical file (CTF) YARD –A statement of agreement between Owner/yard and paint company for this contract –Paint specification as issued by yard including key criteria and data sheets –A summary or full log of work carried out by yard/coating inspector - one for each tank and Non-conformity/repair summary log for each tank - including verified inspection reports –Statement of conformance –Copy of type approval certificate or statement of compliance –Yard procedures (for inspection and repair) audit certificate from class (includes application ). Paint Company –Planned maintenance procedures for in service Ship owner –Maintenance log –Inspection log –Condition log –Class inspection log

DFT Measurement Typical Double Bottom Block WT BHD FWD Long spacing 0.7 – 0.95m 3 – 6m

DFT Measurement : Long & Trans (2 reading/2~3m) : Flat area (1 reading / 5 m 2 ) Flat area 22 points Long and Trans 60 points

DFT Measurement 26 Openings 12 Openings 8 Openings 42 openings – 92 measurements Openings > 400mm – 4 measurements

DFT Measurement Total area to paint 2,790m 2 Total measurements 3,400

DFT measurements Total area of WBT = 240,000m 2 About 40 football fields

Data management - ELCOship Electronic data gathering Local PC Remote database Coating Technical File IMO PSPC Compliant Standard documents Reference drwgs

Verification Tri-party agreement Type approval Test results Process audit Inspection audit CTF audit and sign off – currently cannot be complied with

The Paint Specification The main elements of the specification in the PSPC are already being carried out in many shipyards and have been for a number of years The main items that are new are : –A Coating Technical File has to be produced by the shipyard –All inspectors are to be qualified to a recognised standard –Increased inspection and prescriptive inspection and data collection –Audit by class

Ambiguities There are many ambiguities in the standard: –Salt measurement –90:10 rule –Area judgement and other subjective elements –CTF detail and content –Products approved through testing – will they last 15 years target life –What happens if they do not –Approved inspector There are some guidelines –PR34 from IACS –IACS guidance notes Maintenance requirements Costs of implementation IACS members not acting in harmony – adding costs Conflict with other regulations

Conclusions Added time and cost to the process Needs a bedding in period Needs a cool and calm interpretation In the wrong hands is adding to costs. Places a clear increased burden on yards It is going to get worse before it gets better. Will it bring with it improvements? Is it needed? Can we do better?

Do it soon

Thank you – but how does the poem end? ……Here’s to rust no doubt about it Most of us would starve without it!….. Acknowledgement to Hyun- Kug Lee for some images (Korean Shipbuilders Assoc and Samsung Heavy Industry) for some images