Weld Crack Detection Kit & Spray

How does a weld crack detection system work?

1. Clean the surface of the material with cleaner and wipe thoroughly with a lint free cloth to remove surface contamination. Parts must be at an ambient temperature, before penetrant is applied. Spray the area liberally with the penetrant and allow 10 minutes contact time. If very fine defects are to be located, extend the contact time to 20 minutes.
2. Clean off the penetrant by wiping with a lint free cloth. Complete the removal using a lint free cloth soaked in cleaner. Clean & dry thoroughly.
   
3. Apply developer by spraying on an even film at least 10 minutes before inspecting for fine defects. Inspect in daylight or under ultravoilet light as appropriate. The system will show continuous lines or pin points where there are cracks or porosity.

Why are the pros & cons of using weld crack detection sprays over radiography when non-destructive testing?

1. Unlike ultrasonic & radiographic testing, dye penetrant inspection (DPI) sprays require minimal investment. They can be deployed with minimal training and can be quickly applied.
2. Crack & defects become visible under normal lighting, with no waiting period for data analysis. The contrasting colour of the developer against the penetrant makes even the smallest cracks visible to the naked eye. With no power needed, Dye penetrant inspection kits are a vital component of a welding inspector armoury, allowing for quick & easy site inspection and testing.
3. Radiography, on the other hand, provides a more comprehensive and detailed inspection capability, detecting both surface and subsurface defects. The recordable data given rules out subjectivity and offers a QA department auditable records.
4. In essence, X-ray offers you a more comprehensive look at a welds integrity and won't be affected by surface paint or chemicals on the material surface.