Available fillers and additives give you the abiltiy to customize WEST SYSTEM 105 Epoxy Resin for your specific application.405 Filleting Blend is a strong, wood-toned filler added to WEST SYSTEM Epoxy for use in glue joints and fillets on naturally finished wood. It mixes easily with epoxy and lets you create fillets that are smooth and require little sanding. Its color is a consistent brown, so 405 can be used to modify the shade of other WEST SYSTEM fillers. 8 ounces. For the suitability of fillers for specific applications, see theFiller Selection Chart.