West System 405 Filleting Blend When mixed with a 105 Resin EpoxyHardener mix the 405 Filleting Blend is excellent for filling epoxy joints or fillets on naturally finishes wood. Featuring strong bonding properties, a natural brownwood tone color, and requires very little sanding. 405 Filleting Blend is a fairing filler. Meaning it cures into a light er and more easily sanded material. Generally used for surface applications such as shaping, filling, fairing, or cosmetic applications. All faired