Now that the main body of the canoe is planked, I clamp the strongback to my desk, and sand the hell out of the entire outside of the boat. I start with 100 grit sandpaper, and end up using 220 grit, to get rid of most blemishes. The strongback keeps the canoe rigid while its sanded. I save the sawdust created, just in case, to fill any huge mis-alignments or gaps, and mix it with the glue to form a type of putty, and re-sand if necessary, once I fill them in. When its mostly smooth, I cut the extended stems off the strongback, and remove the canoe.