3M Glass Bubbles K series are hollow, low-density soda-lime-borosilicate glass microspheres designed as high-strength fillers for composites, syntactic foams, and marine applications. Key Features Engineered for 300 PSI crush strength, 0.15g/cc density, and excellent water/oil resistance They reduce weight, improve flow, lower viscosity and minimize shrinkage/warpage compared to silica or talc Ideal for injection molding, deep-sea projects, and buoyancy in underwater syntactic foams Suggested Uses Replace conventional additives in spraying, casting, or molding. Pair with silica thickener to prevent sagging. Bulk resin by 50% volume. Data Sheets Safety Data Sheets note 1 gallon ships in a 5-quart container (e.g. 1 gallon fills 80% of container). Quantity is by volume, not container brim.
