Coating inspection NZ: Quality and safety control guaranteed
Complications can occur during the pre-treatment, application and curing phases of a coating project. There are a number of considerations when coating is applied, for example; the external conditions and the material itself. After the application process, it is therefore important that an independent coating inspection NZ be carried out by an independent certified coating inspector.
Certified coating inspectors carry out inspections on various constructions, such as (rail) bridges, storage tanks and loading stations. In addition, inspectors often draw up maintenance management plans in order to be able to realize a reliable, safe and sound installation together with you. A coating inspector ensures an independent quality control before, during and after the application of the coating.
Inspection procedure : Survey and coating specification
The coating inspection process starts with a site condition survey, which forms a foundation for the coating specification. This condition survey will consider factors such as:
- The substrate and its condition (damage, deterioration, rust, peeling)
- The degree of damage and what measures must be taken to repair
- Any environmental issues which need to be taken into account
Before any part of the coating inspection can be carried out, it is important to write a specification of the project. A kind of project manual. A coating inspector can help with this. In the specification the desired end result is described down to the smallest detail, both technically and aesthetically. The purpose of a specification is minimizing any misunderstandings between project managers, coating applicators, engineers and other employees concerning the intended end result.
The specification needs to clearly describe the owner’s expectations for their project, aesthetically and structurally. It must also include a description of the substrate and the environment the coating will be applied in. A well-written specification contains as much detail as is required to make these expectations clear, in plain unambiguous terms. It is a template, and thus needs to be as accurate as possible for the finished product to turn out as planned.
Some manufacturers actually provide specification services, so that every step of the process is overseen by someone who knows the coating products inside out.
The six steps of a coating inspection
After the coating specification, the application process must be monitored from beginning to end – from surface preparation to final colour and gloss. This process generally consists of six standard steps:
Step 1: Surface inspection, preparation and pre-treatment
The coating inspection of the pre-treatment is seen as the most important control. An optimal adhesion of a durable coating system requires exactly the right pre-treatment. Both the surface cleanliness and the surface roughness are assessed at this stage.
Cleanliness and roughness can be obtained through various techniques. Think of the chemical pre-treatment of substrates, water jets, manual or mechanical rust removal and dry or wet sandblasting.
Step 2: Climate condition assessment
The temperature and humidity are very important for the quality of a coating. At low temperatures, for example, the coating may not cure properly. Furthermore, condensation can ensure that a coating does not adhere well. Climatic conditions are often measured using so-called “multi-meters”. These are digital meters that in many cases are also capable of storing measurements and statistically processing the collected information. In a coating inspection at least the following is inspected:
- Air temperature
- Relative air humidity
- Dew point
- Surface temperature
Step 3: Layer thickness inspection
When a coating system is too thin, the desired protection can not be achieved. Conversely, when a coating is too thick, cracks may occur or the coating will not harden. Layer thickness is therefore specified and measured in microns or mills, but sometimes also in millimeters or (parts of) inches. Today’s measuring equipment is so accurate that layer thicknesses in tenths or hundredths of a micron or mill can also be measured.
Step 4: Curing rate measurement
The coating must be cured to the degree defined in the specification; if the coating is not cured enough the surface lacks hardness, making the finished coating layer more vulnerable to hazards such as abrasion and chemicals.
Step 5: Testing the adhesion sufficiency
It is self-evident that good adhesion of the coating system is important. The current test methods for measuring this are unfortunately all destructive. This means that a piece of the layer has to be removed during the test and then repaired again. We also call this “tensile testing”.
Adhesion tests are often performed on reference plates. These are plates that are treated in the preservation process and therefore have undergone the same treatment under the same conditions.
Step 6: Colour and gloss evaluation
Discolouration can indicate defects in the coating system. It is also important that a homogeneous color result is achieved in the entire production process. A color meter can verify this very precisely. In the automotive sector gloss meters are often used to check the degree of gloss.
The NACE Coating Certified Inspection
NACE International, The Worldwide Corrosion Authority, was established in 1943 by eleven corrosion engineers from the pipeline industry as the “National Association of Corrosion Engineers.” The organization operates worldwide and is globally recognized as the premier certification body for coating inspection.
Having an NACE certified inspector is guarantee that you recieve :
- Recommendations for choosing a coating system,
- Plans for proper quality control
- Quality assurance during and after the application process
- Advice on devising maintenance programs to lengthen the life of your coating system.
There are 3 main certifications for inspectors and depending on your substrate it is recommended to pay attention to the level of the coating inspector.
|Level 1||Performing and documenting basic and non-destructive inspections of liquid coatings applied by brush, roller or spray to steel surfaces|
|Level 2||Performing and documenting non-destructive inspections of liquid and non-liquid coatings to any substrate in a shop setting or under the supervision of a level 3 inspector when working in a field setting|
|Level 3||Unsupervised non-destructive inspections of liquid and non-liquid coatings to any substrate and demonstrate technical knowledge, problem solving ability regarding issues that may arise on site and would be capable of supervising basic (CIP Level 1) and intermediate (CIP Level 2) coating inspectors|
Find a coating inspector in New Zealand
Many companies operating in New Zealand offer coating inspection services. The following are a small selection. If you would like more information about the right company for you, Coating.co.nz works with professional and experienced certified coating inspectors who can carry out inspections for you and draw up cost estimates.
|Coating inspector||Sectors served||Address|
|SGS||Oil and gas exploration and logistics, electricity generation, plant components, agriculture||SGS House, Level 4, 8 Rockridge Avenue, Penrose Onehunga, Auckland, 1061|
|Inspection & Consultancy Services Ltd||Electricity transmission towers, boats, ships & maritime vessels, tanks||45 Domett Street, Taranaki, Waitara 4320|
|Line Tech Consulting||Steel tower, Transmission assets||210 Hazeldean Road, Sydenham, Christchurch 8023|