are the epoxies heartily recommended by John Greven and Mike Doolin. John recommends the SB112 for just about any wood. If you prefer a less viscous filler, the Clear Coat is for you.
Silica thickening powder can be added to our System Three epoxies to thicken them if necessary. It will not compromise the clarity of the epoxy, but does make is harder. John Greven recommends starting with one part silica powder to 3 parts epoxy. He suggests bringing the mix to the thickness of whipping cream. John says many people prefer to make the epoxy thicker for the back and sides and thinner for the top. Mix the epoxy first, then stir in the silica powder until you no longer see any dry spots. Craig Walsh adds that scraping is the fastest way to level the epoxy filler prior to finish sanding.