Sand Less, Turn More: A Guide to Bowl Sanding
Sanding is the job most woodturners do more of than they need to, and almost always for the same reason: the surface coming off the tool isn't as clean as it could be.
The fix starts before the abrasive ever touches the wood. A properly presented bowl gouge, kept sharp, produces a cut that leaves little for the paper to remove. When the cut is right, you might start sanding at 180 or even 240 grit rather than working up from 80.
Knowing what you're looking at matters too. Tool marks run in straight lines around the piece, tear-out shows as dots only on the end grain, and sanding marks from a rotary sander are arcs a cutting tool can't make. Once you can tell them apart, you know when to stop each grit and move down.
The principle is simple: each grit's only job is to remove the marks of the one before it. Stop when those marks are gone, then move on. Spend longer than that and you're only generating heat, which on exotic woods can check or crack the end grain.
Finish by sanding the inside and rim with the same care as the outside, keep the lathe at cutting speed, and don't over-sand. It's the difference between a piece that's a pleasure to finish and one that fights you the whole way.