A method of recycling glass fiber-reinforced polymer composite materials that can provide improved quality recycled glass fiber is described. More particularly, the method comprises pyrolysis of glass fiber-reinforced polymer composite scrap and/or end-of-life material and the subsequent immersion of the pyrolyzed glass fibers in a molten salt bath, e.g., comprising molten potassium nitrate. Immersion in the molten salt bath can eliminate char from the pyrolyzed fibers, as well as removing residual inorganic materials. In addition, immersion in the molten salt bath can strengthen the glass fiber, which can result in the recovery or avoidance of tensile strength losses normally incurred through traditional char removal processes.