ISO 12944

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Page 1 Release Date:31-Dec-05 Ref:

ISO 12944 Module 7 DEFG

Introduction Like many industrial sectors, the Protective Coatings Industry has standardisation associated with it Standardisation is required in order to ensure best practice and a specified level of quality is achieved When it comes to the issue of corrosion protection via the use of protective coatings, it is fair to say that most regions or countries of the world may have their own standardisation & quality requirements that needs to be adhered to Where countries dont have their own, they tend to borrow from the more recognised standards such as those provided by SSPC, NACE, DIN or BS In addition, some customers, such as those associated with oil & gas, will adopt these standards and use them as a framework in developing their own internal standardisation & quality requirements From an IPC point of view, trying to satisfy all the requirements of the many individual, regional and local standards currently in place is an impossible task, and only makes the implementation of a global strategy and product range even more complex It is important that IP as a truly global company should direct its focus on a truly global coatings standard and by that we mean those standards developed by ISO ISO = International Standards Organisation (www.iso.org) it is based in Switzerland and is responsible for the standardisation and documentation of numerous procedures and testing regimes The use of ISO standards fits well with IPC global strategy and allows us to put more focus on adopting and promoting the principles on a truly international stage ISO standards are available worldwide and in many different languages much like our own global product range associated literature such as datasheets & brochures etc This module focuses upon the ISO 12944 international standard which covers corrosion protection of steel structures by protective paint systems




ISO 12944 What is it? In the mid 1990s the coatings industry & corrosion experts from all over the world came together to form a committee to look into the standardisation of corrosion control at new construction After years of work, the result was the standard ISO 12944 Corrosion Protection of Steel Structures by Protective Paint Systems ISO 12944 comprises of 8 parts which deals with all the aspects that are important in achieving adequate corrosion protection of steel structures when using protective coatings at new construction ISO 12944 Who uses it? The standard is intended to be used by structure owners, engineers, consultants, fabricators, applicators and corrosion inspectors who have some knowledge of corrosion to assist in adopting best practice in corrosion mitigation via the use of protective coatings Utilising ISO 12944 at the new construction stage will help to minimise the need for coating maintenance which in turn helps to reduce health & safety concerns, environmental impact and overall structure lifetime costs Another key benefit of using ISO 12944 is that it can help to standardise the terminology and definitions used within the coatings industry This in turn helps to avoid misunderstanding of information which passes between the many different parties involved in a new construction project Everybody is talking the same language When considering the complex sales chain involved in certain PC projects, the use of ISO 12944 throughout the chain can help to reduce complexity and provide unambiguous and easily understandable communications in which all parties can relate to A common language amongst all those involved in the sales chain ISO 12944 was released in 1998 and it has rapidly replaced local standards in Europe e.g. BS5493 and DIN55 928 It has also been adopted where no strong local standards are in place




Within the Americas and Australasia where NACE/SSPC and AS/NZ standards are well established respectively, the switch to ISO 12944 is less advanced, however it is growing in popularity in these areas A large section of our potential customers will not be aware of ISO12944, it is everybodys responsibility to take the lead and introduce it Many engineers prefer dealing with ISO - it is an independent, internationally recognised organization By promoting ISO 12944 within the market, International Protective Coatings can be seen as global, proactive in the industry, willing to accept impartial standards and taking a responsible approach to coating specification ISO 12944 The concept In the broadest terms, ISO12944 makes use of 3 parameters when dealing with the corrosion protection of steel structures at New Construction Durability - The expected lifetime of a protective coating system prior to the first MAJOR maintenance. It is assumed that regular coating inspection and minor maintenance will always be required throughout the structure design life Corrosivity The ability of an environment to cause corrosion, (taking into consideration any special conditions which may affect the performance of a protective coating system) Coating System Specification The recommended coating system generic type which will provide the necessary corrosion protection to meet the both the durability and corrosivity demands. (this includes surface preparation) The development of the ISO 12944 standard has had a significant impact on the protective coatings industry since its release from both the perspective of the customer be that an engineer, architect, fabricator, applicator and the coating manufacturer Anybody who is involved with the provision of advice within the protective coatings industry should have a level of understanding of what ISO 12944 is all about This module summarizes IPs viewpoint, however, it is not a substitute to actually reviewing the standard itself. It is recommended that you read the actual ISO 12944 standard in conjunction with this module




ISO 12944 The Parts As already mentioned, ISO 12944 covers all aspects of protective coatings and consists of 8 parts, these are

ISO 12944 Part 1 General Introduction ISO 12944 Part 1 describes the general scope of the entire standard and makes an early reference to protective functions that are not covered These are functions such as anti-fouling (e.g. Intersleek), storage of chemicals and ballast (e.g. Interline, Intershield), and fireprotection (e.g. Chartek & Interchar) Although not mentioned specifically, the ISO 12944 standard does not cover high heat areas (e.g. Intertherm) The specification of coating schemes involving Interline, Chartek, Intersleek & Intertherm are highly specialised Therefore they require more detailed information, guidance and testing to ensure successful use

This detail can be difficult to capture in a standard such as ISO 12944 which covers such as broad range of corrosion protection issues

The key element of part 1 revolves around the definition of the term Durability and the expected lifetime of a protective coating system Within ISO 12944, durability is expressed in terms of 3 ranges, Low, Medium & High

Part Description 1 General Introduction 2 Classification of Environments 3 Design Considerations 4 Surface Preparation 5 Protective Paint Systems 6 Laboratory Test Methods 7 Execution / Supervision of Paint Work 8 Development of Specifications




An alternative way of describing durability is in terms of coating design life. Many engineers, who will use ISO 12944, can better relate to the term design life. In many cases it is what they are trained to understand Low (L) 2 to 5 years Medium (M) 5 to 15 years High (H) >15 years When talking about coating durability or coating design life, there are some important considerations that must be taken into account. These are :-

The coating design life is dependent upon the degree of surface preparation. In most cases it is assumed that a minimum of Sa2 cleanliness (~SSPC SP6) is achieved prior to coating application

The design life of the coating system is generally shorter than the expected design life

of the structure it is protecting. Design life is best described as the level of coating failure (or breakdown) prior to the first MAJOR coating maintenance work is required

As such, due consideration must be made to ensure regular coating inspection and

expected minor maintenance is carried out over the specified design life The definition of MAJOR maintenance should be agreed by all interested parties in accordance with the standardised degradation of paint coatings described in ISO 4628 parts 1,2,3,4 & 5 Coating design life is not a guarantee time; therefore, ISO12944 offers a standard method of avoiding lengthy and unrealistic lifetime guarantees whilst still offering a meaningful coating design life. This all adds up to helping IPC manage liability from a commercial point of view Most IPC customers will focus their attention towards the high durability >15 year design life. In most cases, customers will require coating systems applied at new construction to last as long as possible in order to postpone the need for inconvenient major maintenance work Durability (or coating design life) only refers to corrosion protection. This should not be confused with durability in terms of colour & gloss retention of high performance finishes. There will potentially be the need for aesthetic upgrades




The use of high performance finishes such as the polysiloxane products (Interfine 878 & Interfine 979) can help to reduce the number of cosmetic upgrades that are required during the lifetime of a structure. This contributes to lowering overall structure lifetime costs ISO 12944 Part 2 Classification of Environments This was briefly covered in the Environment technical module; however, we will go into a little more detail The key feature of part 2 is that it provides a way of defining environments in terms of corrosivity in which steel structures are situated

These environments are known as Corrosive Categories This provides a very useful tool when considering an appropriate coating specification in other words, its a very good starting point Understanding corrosive categories and environments helps to understand WHY & HOW certain coating products are used to prevent corrosion ISO 12944 Part 2 splits the environments into 3 main groups, they are atmospheric, immersion in water and buried in soil Atmospheric The atmospheric environments are classified into 6 corrosive categories defined from weight loss of metallic (low carbon steel and zinc) specimens over a defined period of 1 year The table on the next slide defines the corrosive categories in terms of steel mass loss and gives examples of typical exterior and interior environments In simplistic terms, as the steel mass loss increases, the corrosion rate increases, therefore the greater the atmospheric corrosivity Categories are designated as C1, C2.through to C5-I industrial and C5-M offshore




Corrosive Category

Mass Loss / thickness loss

Exterior Environment Examples

Interior Environment Examples

C1, C2 Very Low, Low




Category Environment Examples Im 1 Fresh Water

Immersion River installations, hydro-electric power plants

Im 2 Sea or Brackish Water Immersion

Harbour areas with structures like sluice gates, locks, jetties, offshore structures

Categories for immersion can be further divided into the following three zones These zones are those which we refer to when talking about severe environment. It is the Interzone product range which are utilised in these areas Zone Description Underwater Area permanently immersed in water (Sub-sea) Intermediate Are subjected to both immersion and atmospheric exposure (also known

as Tidal Zone) Splashzone Area wetted by wave action. Gives rise to very high corrosion rates

Buried in soil Similar to the immersion category, steel metal loss can be difficult thing to measure and therefore to define. So once again, only typical example environments are given Category Environment Examples

Im 3 Soil (Buried) Buried tanks, steel piles, steel pipes

ISO 12944 Part 2 Design Considerations Part 3 focuses upon how the overall shape and design of a given structure can have a significant influence on its susceptibility to corrosion problems Ideally part 3 should be reviewed by engineers and architects and all those involved at the initial design stage and not when the project is up and running




This part can only really be fully implemented at the new construction stage or by major structural modification later in the structure lifetime Examples of suitable and unsuitable designs are reviewed looking at areas such as accessibility, treatment of gaps, water traps, edges, welding imperfections, bolted connections and stiffeners etc. The careful consideration of structural design will contribute towards extended coating design life It is fair to say that this part of ISO 12944 is outside the scope of protective coatings manufacturers such as IPC However, working alongside the designer/architect and highlighting design issues is an important aspect of correct coating specification There could be the situation whereby the customer will expect the coating products to alleviate, or help alleviate, corrosion problems due to design errors Examples of this are the thick film edge retentive coatings where they are relied upon to give good coverage over sharp edges Whilst there are many good products out there, there is no real substitute for good rounded edges and correct repair of substrate defects prior to coating application ISO 12944 Part 4 Surface Preparation Surface preparation has already been covered in detail in the surface preparation modules Therefore there is no need to go into detail here Suffice to say that part 4 gives a very comprehensive guide into the types of surface and the many aspects of surface preparation and the importance of it ISO 12944 Part 4 is a very good reference document and provides a very thorough list of ISO surface preparation standards ISO 12944 Part 5 Protective Paint Systems A basic way of viewing ISO 12944 as a whole is as a tool for providing the customer with a solution to their anticipated structural steel corrosion problems




This means supplying an adequate protective coating system that will meet both the durability and corrosive category requirements The basic three steps to doing this at new construction are listed below

1. Use ISO 12944 part 2 to select the appropriate corrosive category (C2,C4,C5-M etc) in which the steel structure will be located, i.e. the service environment

2. Decide on the design life (durability) requirements of the protective coating system, i.e.

Low, Medium or High see ISO 12944 Part 1

3. Having done 1 and 2 above, you are now in a position to utilize ISO 12944 Part 5 in

choosing the most effective coating system to meet the needs of corrosive category and design life

Part 5 provides a comprehensive list of generic coating systems that have proven performance in the corrosive categories described. These are presented in a series of tables An important aspect of part 5 is the following technical considerations

Suitable, proven generic coating types are listed against all corrosive categories. For example, zinc rich primers figure frequently in the more corrosive C4 & C5 environments, whereas they do not in the less corrosive C3

Coating system design life (or durability) is satisfied via dry film thickness (dft) The general rule followed is that for a given coating system, an increase in design life

is satisfied via an incremental increase in dft However, this does not mean carte blanche on film thickness there are maximum acceptable limits for each IPC product which must be adhered to Selecting coating specifications that comply with ISO 12944 part 5 provides the customer with:-

Confidence that the corrosion protection will meet the demands of the corrosive category and intended design life

An objective approach to coating selection A simplified matrix of proven coating systems to chose from A meaningful coating design life A globally accepted standard




It is good practice for all involved in specifying protective coatings to review part 5 and get an understanding of the approach used by ISO 12944 with regards to how coating specifications are put together The technical considerations within ISO 12944 Part 5 in terms of corrosive category, durability, individual product dry film thickness range and product compatibility form the basis of the technical checks contained within Interspec By Utilising Interspec you are automatically taking advantage of ISO 12944 However, it is important to appreciate that Interspec (and therefore ISO 12944) is not 100% foolproof There is still the requirement that the specifier (or user of Interspec) has knowledge of IPC products Care should always be taken to ensure that the IPC coating system specified is suitable for use What ISO 12944 will not do is protect us from claims due to poor coating specification The use of part 5 is very much at the heart of what ISO 12944 is all about.

ISO 12944 is essentially a specifying tool Primer Definitions Another important feature of ISO 12944 part 5 is the primer definitions In this case, a zinc rich primer is defined as one which a minimum of 80% zinc dust pigment content by mass in the dry film Hopefully, this may help to bring some clarity into the protective coatings industry with regards to what is considered a zinc rich primer All IPC global Interzinc zinc rich primers meet this definition (e.g. Interzinc 52, 22,22HS,315 etc) Dry film thickness (dft) The dfts quoted in part 5 are in multiples of 40m, IPC tend to work in multiples of 25m (25m = 1 mil)




Slight modifications to the way Interspec utilises ISO 12944 have been made to accommodate this Recommended maximum dfts per coat are x3 that specified, this in many cases is too high and is not necessarily in agreement with IPC philosophy The maximum dft per coat for a given product should always be verified via the technical department. A good guide is x2 that specified ISO 12944 Part 6 Laboratory Test Methods The idea behind part 6 is to provide some meaningful laboratory test methods and pass criteria for those coating systems where there is no realistic proven real-time performance data (or track record) in the specific corrosive category As such it is intended that the results of the tests are considered as an aid in the selection of suitable coating systems for the specified corrosive category and design life (durability) Consider part 6 as being fitness for purpose testing (see Product Testing module) The laboratory tests specified within ISO 12944 Part 6 are only concerned with anti-corrosive performance There is no reference to mechanical performance such as impact, abrasion or flexibility etc From a customer perspective, if there is no track record, then the next logical step is to for laboratory test data to back-up the performance claims from the coating manufacturer Therefore, part 6 becomes a central consideration the customer (be that an owner, engineer or specifier), must take into account when choosing a suitable new protective coating system where track record is not available However, there is a slight issue Since the release of the ISO 12944 standard in 1998, Part 6 has been a real focus of attention due to the divided opinion within the industry (both customers and coating manufacturers) on whether the test methods described are acceptable It has been IPCs position that the test methods as they currently stand are NOT ACCEPTABLE




The lack of acceptance of part 6 has revolved around the fact that some coating users, consider the tests as being out of touch with current industry practices

They do not include the latest in cyclic corrosion testing They do not include product identification or fingerprinting In particular, the tests specified within Part 6 do not reflect current industry practices for

the more aggressive C5-M and Im2 corrosive categories. This lack of acceptance has resulted in the following:-

1. The laboratory performance test requirements for offshore C5-M & Im2 protective coating systems was revisited and dealt with via a dedicated performance based standard outside of ISO 12944 part 6, the result was the development of ISO 20340 (see Performance Specifications module)

2. An ISO working group committee was assembled to review and update ISO 12944 part

6 and include cyclic corrosion test methods and product fingerprinting.

3. At the time of writing, this revision of Part 6 is perhaps some way from being formerly released. It may be that the earliest release will be towards the end of 2006

ISO 12944 Part 7 Execution & Supervision of Paint Work This part of ISO 12944 deals with the execution and supervision of coating work on steel structures whether it is in a workshop, a yard or on site As such, the intended audience for this part are the companies who are contracted with the actual coating application. (e.g. paint contractors, fabricators, OEM etc) The objective of part 7 is to ensure that a minimum level of quality is achieved at the coating application stage This is very important due to the fact that the owner of the steel structure may have a different view of expected quality compared to that of the coating contractor By using part 7 as a guideline, all parties involved can agree on the minimum that is required




Part 7 focuses on 4 key elements

1. Preconditions - This covers subjects such as quality personnel requirements and workmanship, conditions of the substrate, health & safety issues, coating material supply and storage

2. Execution of coating work - Areas such as coating condition prior to application, agreed

methods for dry film thickness measurement, stripe coating requirements, application conditions and methods are covered here

3. Supervision of the coating work - This covers the all important supervision or

inspection of the coating work

The level of supervision will normally be determined by the importance of the structure or asset in question and may involve the need for a NACE or FROSIO accredited coatings inspector

The function of the supervisor or inspector is to ensure that the protective coating complies with the project specification

It is generally the structure owner or engineer who will drive the need for supervision and inspection

4. Coating reference areas - This covers a very useful way of establishing a minimum

level of quality that is to be achieved during a coatings application project. They may also be used for guarantee purposes

The following comments can be said regarding reference areas:-

They should be located in representative areas which are typical of the corrosive categories in which the entire structure is exposed

All surface preparation and coating application work should be supervised by all

interested parties (including IPC) and reach agreement on the level of quality that needs to be achieved

It is intended that the agreed level of quality achieved in the reference areas should be

reproduced over the entire structure being coated All work carried out in reference areas should be fully documented

IPC utilise the concept of coating reference areas within some standard guarantees




Where there is a case of premature coating breakdown on a structure, the coating supplier may be liable if the breakdown also occurs within the allocated reference areas since this could indicate a coating problem rather than a surface preparation one However, if the coating breakdown is not replicated within the reference areas, this could indicate failure due to a poorly prepared surface or improper application of the coating system. In such an instance, it is the applicator that may be liable This helps to manage liability from a commercial aspect ISO 12944 Part 7 does provide some guidance on the recommended size and number of reference areas on a particular structure. Some examples are shown in the table below Structure size m2 (painted area)

Recommended maximum number of reference areas

Recommended maximum total area of reference areas

Upto 2,000 3 12m2

Above 5,000 to 10,000

7 50 m2

Above 10,000 to 25,000

7 75 m2

Above 50,000 9 200 m2 ISO 12944 Part 8 Development of Specifications Part 8 of ISO 12944 is targeted at the coating specifier, or anyone who has responsibility for the development of a specification, be that an entire project specification or a more focused protective coating specification Part 8 provides a framework in which parts 1 to 7 of ISO 12944 are utilised in the development of a new construction specification It does so by providing examples of checklists and flowcharts in which all the relevant parameters are taken into consideration for both new work and maintenance For the IP salesperson, part 8, as with parts 3 and 7, is a good reference document The tables within part 8 can provide some of the basic technical questions that need to be asked prior to offering a coating specification to the customer

Documents

ISO 12944