Pipeline Coatings Cathodic disbonding testing

Protective coatings are applied to buried or immersed metallic structures thus providing a primary line of defence against corrosion and is usually used in conjunction with Cathodic protection. To test the coatings ability to prevent corrosion attack a cathodic disbonding test is used.

This cathodic disbonding test method determines the resistance to cathodic disbonding of a coating system between coating and steel substrate, resulting in loss of coating adhesion.

AS4352-2005 Test Cell A

LMATS performs cathodic disbonding test in accordance to AS 4352-2005. Cathodic Disbondment Test is a test method to evaluate the long-term performance of coatings used for  protecting metal pipes and pipelines being installed into underground environments. The Cathodic Disbondment Test is a well-known and generally accepted laboratory testing procedure for pipeline coatings.

In this test, an intentional defect (holiday) on a coated panel or section of the coating to be tested is immersed in a saline solution contained in a test cell and cathodic protection is applied. After a specified period, the panel is examined for evidence of coating disbondment around the intentional defect and if present, the radial disbondment and disbonded area are determined.

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A good cathodic disbonding test result (ie a small delamination radii) would indicate that the coating could be reasonably expected not to delaminate to a large extent in the presence of cathodic protection and a small coating damage with the steel surface exposed to the soil.

This makes cathodic disbonding testing an essential tool for the quality control of pipeline coatings and other equipment in a reactive environment.

Cathodic disbonding testing quality control applications

  • Ships and boats
  • Marine -  jetties, harbors, offshore structures
  • Bridge, Building, Dam Construction - Steel in concrete - concrete reinforcement, rebar coatings, Coated Steel Reinforcing Bars
  • Galvanized steel - hot-dip galvanizing
  • Pipelines constructed from steel
  • Pipelines constructed from pre-stressed concrete

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Contact LMATS for all your protective coating cathodic disbonding testing requirements

LMATS performs electromagnetic test on various engineering components to determine thickness of metallic and non-metallic coatings, weld overlay and residual bond, corroded samples wall thickness and similar applications.

The test standards applied are AS 2331.1.4, ASTM E376 and similar international standards.
Simply request LMATS ’ supportive staff and they will assist you to complete your task in time.

Coatings for wear resistance, lubrication and electrical conductivity are subjected to microstructural examination in the aerospace and offshore industries to determine the quality and integrity.

The microstructural examination involves coating thickness, evaluation of voids or porosity, unmelted particles, interface appearance, laminations, oxide or oxide clusters, cracks, etc.
LMATS performs microstructural examination of coatings frequently for its clients in the aviation and offshore sector.

Protective coatings are bonded on the subsurface using one of the adhesive mechanisms.



The bonding or adhesion of the coating on the subsurface is very crucial in severe corrosive environment.



A coating bond test or adhesive test is performed to measure the required tensile force to break the coating (quantitative test) or bend test is performed to see of the coating is peeling or flaking off from the subsurface ( qualitative test). LMATS hold proven procedures and NATA accreditation in coating bond / adhesion test.



The test is performed in accordance with AS 1580.402.1, DNV, Offshore specifications, EXXON Mobil, ESSO Shell specificationaerospace specifications and other similar standards.

Holiday test or a Continuity test is one of the non destructive test method applied on protective coatings to detect unacceptable discontinuities such as pinholes and voids.

The test involves checking of an electric circuit to see if current flows to complete the electrical circuit.

A Holiday test or Continuity test is performed by applying low voltage (connected in series with an LED or noise-producing component such as a piezoelectric speaker) across the chosen path.

If the electrical flow is detected then the test area is termed as conductive indicating presence of discontinuities such as pinholes and voids.

This test is commonly used in the offshore industries where piping and structures are coated with non-conductor coatings.

LMATS professionals are trained in Holiday (Continuity) test method in accordance with AS 3894.1, ASTM G62 and similar national and international standards.

holiday testing1Holiday tester

  1. Coating Mass Test