When you've focused on cleaning the worst areas, utilize a hose to obtain the total floor wet. Periodically sprinkle the etcher or cleaner/degreaser evenly around the total area and scrub The entire floor using your brush. Etching the concrete will give the epoxy an even better surface to bond to. http://bookmarketmaven.com/story6004424/5-simple-techniques-for-the-epoxy-floor-coating