This strong, wood-toned filler is good 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. Designed for west resins, but suitable for all epoxy and polyester resins except as noted. 405 filleting blend is a strong, wood-toned filler for use in glue joints and fillets on naturally-finished wooden interiors. Polyester or epoxy resin.