Scratching Tool acc. to van Laar, Model 426 - ERICHSEN

The Erichsen Model 426 Scratching Tool, accredited to van Laar, is an essential instrument for precision scratch testing on coated surfaces. Crafted with a ball-shaped hard metal pin of 0.5 mm diameter, this tool is securely housed within a ballpoint pen-shaped holder made from anodised hard aluminium. Its design offers both comfort and stability during use, ensuring accurate and reproducible results.

Endurance and Application

Proven durability under rigorous conditions, this tool has endured tests involving 2000 scratches of 90 mm each without any damage to the spherical point. It is indispensable for scratching-in the St. Andrew’s cross into test panels, a critical task for short-term and endurance corrosion tests. This facilitates the assessment of a coating’s protection against substrate rusting beneath it (“underrusting”). Ideal for a plethora of forced corrosion tests, including salt spray and accelerated weathering, the Model 426 is a versatile tool tailored for comprehensive surface analysis.

Test Principles and Evaluation

The Scratching Tool allows for the creation of precise incisions in protective coatings, essential for the systematic analysis of “underrusting” progression. Evaluation measures include tracking the spreading rate of rust and understanding the adhesion quality of coatings. The tool’s efficiency in providing key insights into corrosion resistance makes it invaluable for research and quality control in paint and coating applications.