Jan 16, 2020· Preparation – Sanding of Epoxy Resin. The process begins with wet sanding. Wet sanding sandpaper is used for this. As the name suggests, this can also be used with water, as the abrasive grains are applied to a special, waterproof fabric. Wet sanding involves carefully sanding from coarse grit from grit 120 to grit 1000 in circular movements.