Wood Flour, when used alone as a filler with epoxy resins, cures to a hard solid, perfect for filleting, bonding or filling. One of its primary qualities is its color, which allows fillets and joints to easily blend in when used on wood components. While the Wood Flour acts as a thickening agent, when used for filleting in conjunction with other fillers, the combination of particle sizes allows the filleting material to stay put while still feathering out to a finer edge than with one type of filler alone. A good rule of thumb is to mix equal amounts of mixed epoxy with Colloidal Silica, and then add Wood Flour until the consistency is similar to peanut butter. The liquid sheen should just go away when the material has been mixed correctly. MAS recommends Medium Hardener with FLAG resin when filleting.