J-B Weld KwikWood Epoxy Putty
In addition to the liquid epoxy that JB Weld makes for wood, they also provide an epoxy putty specifically formulated for working with wood. I believe this is the only epoxy putty specially formulated for wood that's available on the market. It is specifically formulated to use as a filler, repairing and rebuilding wood that has become damaged. It contains no solvents, so it will not stain, or leave any chemical residue which will soak through paints and other finishes. The epoxy putty has a 15 to 25 minute work life and fully cures in one hour. Cured, this epoxy putty provides 900 PSI of tensile strength. It can be machined (including drilling, tapping and sanding once it is cured) while the light tan color accepts paint well.