When you've focused on cleaning the worst parts, utilize a hose to find the complete area wet. Periodically sprinkle the etcher or cleaner/degreaser evenly around the full region and scrub The full floor utilizing your brush. Etching the concrete will give the epoxy a better surface area to bond to. http://bookmarkswing.com/story6806337/spraying-epoxy-floor-coating-fundamentals-explained