Coatings are critical to extending the life of many assets. ALS can ensure your coating meets the requirements you need. When things go wrong, ALS has the expertise to determine how a coating has failed and what to do next.
Surface Coatings are an essential tool for fighting the billion dollar problem of component degradation due to corrosion and other damage mechanisms.
When designed, specified and manufactured correctly, coatings significantly extend component life for a relatively low cost.
ALS steps in as your independent coatings advice partner, helping you answer questions like:
- Has my coating been correctly specified / applied?
- Why is my coating not stopping corrosion?
- Why is my coating delaminating or blistering?
- Does the coating meet my manufacturing standard, including properties such as correct hardness/cure, adhesion and thickness?
- What surface preparation and atmospheric conditions must I achieve to successfully apply my coating?
- Does my coating have any defects in it? How will these affect performance?
- Why did my coating fail?
- How can I successfully repair my coating so that it doesn’t fail again?
The ALS advantage in understanding our client’s critical coatings is our ability to combine staff with coatings expertise with effective inspection techniques to determine the important properties of a coating that affect its performance. ALS provides NACE certified coatings inspectors, scientists and engineers, providing visual inspection to relevant AS, AS/NZS, ASTM and ISO standard such as:
- AS/NZS 1580.400 set Paints and Related Materials – Methods of test - Cured Coatings – Performance by mechanical testing;
- AS 1627.9 Pictorial surface preparation for painting steel surfaces;
- AS 2309 Durability of galvanized and electrogalvanized zinc coatings for the protection of steel in structural applications – Atmospheric;
- AS/NZS 2312.1:2014 Guide to the protection of structural steel against atmospheric corrosion by the use of protective coatings - Paint coatings;
- AS/NZS 2312.2:2014 Guide to the protection of structural steel against atmospheric corrosion by the use of protective coatings - Hot dip galvanizing;
- AS 2331.0-2006 Methods of test for metallic and related coatings - Method selection guide; any of the sub sections;
- AS 3894 – Site testing of protective coatings;
- AS/NZS 4680:2006 Hot-dip galvanized (zinc) coatings on fabricated ferrous articles
ALS also provides:
- Comprehensive on site and laboratory coatings testing, with many tests holding NATA certification and all provided under our ISO 9001 accredited quality systems.
- Technical consulting through our scientists and engineers who assist with understanding the root causes of coating failure, recommendations for corrective action and repair procedures where require.
- Coating selection advice as to suitability of coatings for particular environments and specification of suitable application, inspection and maintenance programs.
Specific coating tests that ALS provides include:
Epoxy Mix Ratio Testing
Epoxy based coatings fail on occasion due to incorrect ratios of the two parts that form the epoxy coatings.ALS provides testing to confirm the mix ratios of in service product, providing both.
- A valuable quality control step to ensure that coating meet specifications.
- A valuable investigative technique to understand why coating are not performing as expected.
Dry Film (Coating) Thickness Testing
Dry film thickness testing assesses the thickness of any surface coating present on a metallic component. Testing is to Australian and international standards (refer left):
Advantages – Positive confirmation of coating thickness of a product for compliance purposes.
Applications – Assess coating thickness of all coated surfaces with conductive substrates.
Holiday (Continuity Testing)
Coated surfaces can have minor breaches not visible to the naked eye. Holiday testing applies a small current to the coated surface to detect such breaches. Testing is provided to standards such as:
- AS 3894.1- Site testing of protective coatings - Non-conductive coatings - Continuity testing - High voltage ('brush') method; or
- AS 3894.2- Site testing of protective coatings - Non-conductive coatings - Continuity testing - Wet sponge method.
Advantages – Rapid scanning of coatings for defects frequently not visible to the naked eye.
Applications – All coated surfaces with conductive substrates.
Coating Adhesion and Peel Testing
The adherence of coating to the material to which it is applied (the substrate) is critical to a coating’s performance.
Separation / Delamination at the interface between substrate and the coating can make the coating liable to cracking and also can expose a void that can preferentially fill up with corrosive materials such as moisture.
ALS performs testing, including peel tests, that confirm that correct adhesion has been achieved.
Surface Roughness Testing
Many coatings require not only a clean surface upon which the coating is applied but also a particularly surface roughness to ensure that coating can bond to the surface effectively.
ALS provides surface profile assessment to:
- AS 3894.5-2002 (R2013): Site testing of protective coatings
Testing to this standard giving surface roughness values for Ra, Ry, Rz and Rq.
Actual surface profiles can be assessed using metallographic examination by replication of specimen examination, where needed.