Nancy, I built a 13 and think it is a great boat. I liked using a foot long piece of 2x4 as a sanding block and 80 grit sand paper. The problem with usine a power sander, if you are not very careful, is that cured epoxy is harder than the wood so when you sand away at those drips and gobs at the chines the sandpaper is going to work on the wood quicker than on the epoxy even if the epoxy is a little higher. Once wood is taken away you can't put it back. A smaller block of wood 1x2" by 4" is good for working at the ends of the boat where a bigger block or sander would take away adjacent areas as well. A random orbital sander is wonderful for sanding areas that would normally consume many sheets of sandpaper and elbow grease.