405 Filleting Blend Adhesive Filler is a strong, wood-toned epoxy filler for use in epoxy joints and epoxy 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 Filleting Blend can be blended with other WEST SYSTEM Fillers to modify the shade of thickened epoxy.
VIDEO: Adding Fillers to Epoxy
Gluing plywood structures together with epoxy fillets saves considerable time constructing the joints and reduces overall weight of the structure compared to more traditional methods using wooden cleats and screws. The strength and gap-filling qualities of epoxy eliminate the need for precisely fitted wood cleats that otherwise require time and skill to create. When gluing with conventional adhesives, that are non-gap filling such as resorcinol glue, wood cleats need to be well fitted, need to be wide enough to provide sufficient glued surface area and provide enough thickness for screws to be driven into. Building with epoxy fillets is especially beneficial when attaching bulkheads to hull sides, attaching hull sides to hull bottoms where the faces of the plywood are coming together at ever-changing angles.
Because epoxy can be thickened with high-density fillers into a non-slumping consistency it can bridge large gaps in wood joints, without loss of strength, thus saving a great deal of time labor otherwise needed to create a strong joint. A fillet is a continuous bead of thickened epoxy mixture applied to the angle created between two parts. It increases the surface area of the bond and serves as a structural adhesive and brace. Filleting creates an effective glue joint that requires no fasteners of any kind and can result in a joint that is as strong as the parts being joined together.
An epoxy fillet can be especially effective when joining parts that meet at difficult angles like where bulkheads meet the hull sides near the bow. Other instances would be where plywood hull sides meet the hull bottom or chine, where hull sides meet at the bow and where hull sides join the deck at the sheer. Historically these joints required well-fitted pieces of wood that the plywood could be glued and screwed into.
Read more about bonding with epoxy fillets at Epoxyworks.com.