Epoxy wood repair products are perfect for fixing rotted wood window sills, door jambs, porch railings and other house trim parts that would be difficult or expensive to replace. Most epoxy repair products consist of a two-part epoxy putty to fill cavities in the wood and a separate two-part liquid epoxy consolidant to stabilize the wood until you use the epoxy putty.
Dig out and remove the rotted wood. Harness the wood chisel to the rotted area with the hammer and gouge out the rotten wood, working back to the sound wood. Drill a collection of 1/4 inch holes in and around the area to be repaired, spacing the holes about 1 inch apart. Avoid drilling all of the way through.
Mix the two parts of this liquid epoxy consolidant. Pour equal amounts of this liquid epoxy and the hardener to the plastic squeeze bottle and stir to mix them. Squeeze the mixed liquid consolidant to the holes and onto the wood in and around the repair place. Utilize the fluid to the wood with the disposable brush. Allow to harden overnight.
Scoop equal amounts of epoxy putty and putty hardener onto a clean, dry piece of hardboard or plywood. Each scoop ought to be about the size of a golf ball. Combine together with the putty knife until thoroughly mixed. Use within thirty minutes. Apply the mixed epoxy putty into the area needing repair. For large, heavy repairs, cut or split little wood blocks to fill in the cavity and pack epoxy putty around the filler blocks. Shape the epoxy putty together with your hands to approximate the form of the surrounding regions. Allow to harden overnight.
Refine the form of the mend, starting with a coarse wood rasp to grind off the major humps and bumps. Switch to wood files and seams as you become closer to the original form. Use flat or round rasps and files as appropriate. Finish shaping with fine 80 grit and 120 grit sandpaper so the profiles of this repair and adjoining sound wood match.
Wipe off any dust. Prime the mend and adjoining sound wood with one coat of alkyd primer. Allow to dry overnight. Apply another coat of alkyd primer followed by 2 coats of acrylic finish paint that matches the original color.