Originally Posted by
John K Jordan
What size is the bowl? What wood? The prominent ring figure reminds me of some magnolia I have, although I've seen others similar, including some maple. Some wood is more prone to tearout.
Unless you can dent the wood easily with your thubmnail at the tearout it's probably not rot or soft enough to cause tearout .
Any on the outside? It looks clean elsewhere. If on the inside bottom only perhaps it is in the tool or technique. In that case, what tool did you use for finish cuts? (Smoothing with a flat-top carbide or other scraper can sometimes be a problem.) Light cuts with a very sharp and honed bowl gouge with a fairly steep "bottom" grind might have taken care of it. In some cases following the gouge with a negative rake scraper can help.
It looks like the the tearout may be fairly deep in which case sanding may be difficult and need to start with fairly coarse grits after it's dry. It may help to apply sanding sealer first.
What I usually do instead of coarse sanding is remove tearout (and toolmarks) with curved hand scrapers. A sharp scraper can smooth the surface quickly and without causing the unevenness sanding can cause on the curved surface. And eliminate the cloud of dust!). Might be a good technique to add to your kit.