Is the paint "hard" enough? We take you inside the lab: sand and gravel impact tests reveal the protective power of coatings.

Many people ask when choosing paint or coatings: “How effective is this paint? Is it scratch-resistant? Is it impact-resistant?” Just reading the instruction manual isn’t enough. Today, we’ll take you inside a professional paint manufacturing plant’s laboratory to conduct a rigorous “survival challenge”—the Gravelometer Test—to reveal the truth. What is a Gravelometer Test? Simply put, this test simulates the real-world scenario of gravel and sand from the road impacting a car or object at high speed during everyday driving. If the coating can’t even withstand the impact of small stones, its protection of the substrate is meaningless. Experiment in Action: The “Baptism” of 3 kg of Sand In the laboratory, the testing personnel operated with meticulous precision and professionalism: Preparing the “Ammunition”: The personnel poured 3 kg of sand of varying coarseness into the gravelometer. This wasn’t ordinary sand, but rather particles in a simulated, realistic proportion in the natural environment. Fixing the Sample: A metal sample coated with paint was firmly fixed to the impact port, ensuring the coated surface faced the direction of impact. This concentrated the firepower, testing the performance of the same area under concentrated impact. Impact Test: The moment the valve opens, all the sand and gravel pours out like water, bombarding the coating surface at high speed. Depending on different industry standards, multiple repeated tests may be required. Result Judgment: Details Reveal the Truth After the impact test, the testers will conduct a detailed evaluation: Visual Inspection: Observe whether there is any cracking, peeling, or flaking at the impact point. Tape Tear Test: This is a more professional evaluation step. The testers will use special tape to stick to the damaged area and tear it forcefully to test the adhesion between the coating and the metal surface. Summary If the damaged area is very small, or only a slight dent remains without breakage, it indicates that the coating has excellent toughness and strong adhesion. Only paint that passes this “brutal test” can provide long-term and stable protection for your products.