Are you using heavy duty floor sanders or are you trying to do this by hand or with light duty sanders? It sounds like you are using lightweight equipment and are ending up just buffing the floor. If you use industrial floor sanders with a heavy enough grit it should be just chowing through the finish and taking off 1/8" of wood as well. This is the only way worth doing it, anything less won't likely work out that well. Be advised, refinishing a floor will beat you up and take you 2-3 times as long as the pros. When was the last time you spent an entire day on your knees like you will need to with an edge sander? The first thing you need is professional knee pads.