Thicker and More Malleable
3M Short Strand Reinforced Filler is thicker than regular filler, so it requires a bit more effort to mix. Compared to long strand fiberglass filler, short strand filler is also a bit more malleable and softer. Fiberglass filler is great for applying over welded areas and can be used as a build layer where thicker applications of body filler are needed.
A Unique Line of Reinforced Filler Products from 3M
Altogether, the 3M line of reinforced filler products offer users a unique and flexible array of repair solutions. Each product is reinforced with short fiberglass strands, long fiberglass strands or milled fiberglass. These reinforced fillers are significantly stronger than regular fillers and are waterproof. They are great for repairing fiberglass and rust holes in metal.

3M 68342, Cubitron II Cloth Belt 967F, 36+ YF-weight, 2 in x 72 in, Film-lok, 7010299098, 50 per case
3M 47201, Polyurethane Sealant 540, Black, 600 mL Sausage Pack, 7100198009, 12/Case
3M™ 53797, Flexible Diamond Belt 6451J, 1/2" Dia x 18" L, M125 Micron, Type G, Pattern B2, 7010509272
Dynabrade 96101 Dynabrade Air Lube 10W/NR 24 Per Box
Dynabrade 94990 1/4" Female Composite-Style Coupler with 1/4" Male Plug Assembly
Dynabrade 11476 Dynabelter Abrasive Belt Tool, Heavy-Duty 
