I had similar problem with my Long Shot. Dacron smoothed out very nice after heating, but waves came back after painting with Rustoleum Oil Base paint. Tried heating again and waves would disappear only to come back after it cooled. Some comments about thinning of the paint potentially causing the probIem. Not sure what was the cause but the paint can says to thin to a maximum of 5%. Boat looks and paddles okay, just disappointing it's not drum tight.