"410 Microlight is the ideal low-density filler. When you blend it with epoxy, it creates a light, easily-worked epoxy fairing compound. It’s especially suited for fairing large areas. We formulated Microlight to mix into epoxy more easily than typical fairing fillers.After epoxy thickened with 410 cures, it is about 30% easier to sand than most other epoxy-based fairing compounds. Epoxy thickened with Microlight feathers to a fine edge. It’s more economical for large fairing jobs.We don’t recommend using 410 under dark paint, or other surfaces subject to high temperatures.