3M™ milled fiberglass body Filler features short strand chopped and milled fiberglass, making it an excellent reinforcement for repairing holes, cracks and tears in fiberglass as well as metal and SMC. Ideal for automotive and marine repair, this waterproof fiberglass body filler features a two-part high resin formula that delivers smooth spreading, excellent sag-resistance and bond gapping. Featuring a combination of malleability, smooth fill and ease of application, our 3M™ milled fiberglass body filler features milled, chopped strands of fiberglass which make for excellent reinforcement during auto body and marine repairs. This fiberglass filler is formulated from polyester resin/styrene base, ideal as a build layer where thicker applications of body filler are needed. The two-part formula delivers exceptional gap bonding and sag resistance on larger holes in metal, fiberglass and SMC. When properly mixed, applied and cured with hardener such as 3M™ cream hardener (No. 05766), 3M™ milled fiberglass body filler is waterproof, extremely durable. It acts as a reinforcement and readily accepts body fillers for final shape and featheredge. Very simply, 3M™ milled fiberglass body filler is the right product at the right time in collision repair operations. Its combination of high resin and chopped strands make it excellent for gap spanning and thicker applications, it's a great example of what 3M™ does best: Science. Applied to Life™.