Sonotube - Uncured Epoxy Coating - View from Back End
  Sonotube-Uncured Epoxy Coating-Back End  
This is a photo taken from the back end of the tube. The epoxy will continue to cure for nearly a week before sanding commences. Rotating the tube around the chain suspended towel wrapped PVC pipe (a quarter turn a day) will help reduce ellipsoidal warping.