Can you still spray expired paint? Manufacturers teach you 4 quick ways to identify signs of paint deterioration.

Can you still use the paint stockpiled in the warehouse? Forcing the use of deteriorated paint can lead to serious consequences such as the paint film not drying properly and loss of adhesion. As a professional industrial paint manufacturer, we teach you how to quickly identify the danger signals of expired and deteriorated paint using a four-step method: look, smell, stir, and test, to avoid project losses. At construction sites or warehouses, you often find some long-stored paint. Many people think that paint can be used as long as it’s not completely dry, but this is a huge misconception. Using deteriorated paint can not only cause color deviations but may also lead to devastating quality accidents such as coating peeling and prolonged drying. Expired paint is unusable; paint that has hardened and cracked is also unusable. As an industrial paint manufacturer, we teach you how to identify the “SOS signals” of paint: 1. Severe “Hard Settling” phenomenon: Upon opening the paint can, you find a thick layer of hardened, mud-like solid at the bottom that cannot be pried off with a stirring rod. Judgment: 1. **Slight sedimentation:** Slight sedimentation that can be dispersed by stirring is normal; however, “hard sedimentation” means the anti-rust pigment and resin have completely separated and clumped together. Even if diluted, this paint will lose its anti-corrosion properties. 2. **Unremovable “Skinning”:** A tough skin forms on the paint film surface. Judgment: If it’s only a thin layer, it’s still usable if the internal liquid is uniform after removal; however, if the skin is extremely thick and the paint is cloudy, it indicates that the resin has undergone oxidation, significantly reducing the leveling and adhesion of the paint film. 3. **Pungent odor or bloating:** Gas is emitted when the can is opened (bulging), or a strong sour or musty odor is detected. Judgment: This is usually due to bacterial contamination of water-based paint or a chemical reaction in oil-based paint components producing gas. This paint has completely lost its performance and must be discarded. 4. Stringing and Gelling Phenomenon: The paint becomes viscous like jelly, or long strings appear when the stirring rod is lifted, and it cannot be diluted evenly evenly with thinner. Judgment: This indicates that the paint has undergone a “polymerization and gelation” reaction. Do not force it onto the spray gun, otherwise it will clog the spray gun and produce a very poor surface finish. Conclusion: Paint has a lifespan. Industrial paints typically have a shelf life of 6-12 months. A “first-in, first-out” (FIFO) storage management system is recommended. If you are unsure about the paint’s condition, the safest approach is to contact the manufacturer for a small-scale sample test.