Prior to removing the rings, we use the belt sander with 80 grit paper to smooth out the staves. We do this to make sure that the staves can be held down flat at the biscuit router and that they don’t have any rough bumps that would throw things off. In order to get the sander over the entire barrel, we take off one ring at a time toward the end of sanding. It helps if you have spare rings, especially one that fits near the top of the barrel. Just being able to position a ring in another spot will allow a way to get the belt sander over that area.