Coating inspection is known to be the simplest form of non destructive testing. However, some special tools are required like Surface Magnetic Thermometer. It is a tool that is used to measure steel substrate temperature. It must be allowed to stabilise on a surface. The inspecting team implies it on the actual location, avoid direct sunlight, and often calibrate.
These information are then used to calculate dewpoint and relative humidity of the inspected element. Dewpoint calculator is also used to calculate the temperature and humidity. Coating inspection is a specialised form of non destructive testing that measures the thickness of the material and finds out any hidden damage inside the metal.
Pre-surface prep inspection
Before the start of surface preparation for coating, all necessary construction and modification should be completed. This includes grinding of welds and sharp edges and filling of pits. In the same manner, the surface must be free from all contaminants. Also, when inspection is to be done, make sure that the job site is ready without forming clutter. Also, be sure that the safety aspects such as ladders and scaffolding, power, and traffic control are in place so that the inspector can safely perform his/her duties.
All new mineral and slag abrasives must be inspected for physical and chemical properties as described in SSPC – AB 1. Recycled ferrous metal abrasives should be checked to ensure cleanliness and avoiding fines as described in SSPC – AB 2. The abrasives should be properly labelled for identification. Even if a sieve analysis is provided, it is prudent to run a check at the job site or retain a sample for later analysis.
Coating inspection is a simple test that can be conducted for contaminants or fines in the abrasive. It is applied to check:
• Oil or grease that forms a surface sheen
• Acidity or alkalinity with pH paper
• Colour or turbidity from dirt
• Soluble salts by conductivity or deposition upon evaporation
• Fines suspended in or at the surface of the water
Blasting equipment check
All air compressors and blasting equipment must be checked to maintain functionality, clean operation and safety. Hand or power tools should also be checked for operation and safety, and thus, must be used only as specified in their standard operating procedures. These checks should be made before the start of abrasive blasting and periodically thereafter, especially after a change of abrasive.
Various industries in Melbourne must undergo this specialised form of non destructive testing to prevent accidents and losing lives, thereby closing the organisation forever.