The second attempt did the trick. No portholes or anything else fancy. I worked from a 8” x 2” chunk of maple, used a parting tool to create a deep channel around the rim, taped around the cove to create a dam, and then poured the resin.
I made sure to follow the directions for mixing the resin and hardener - paying special attention to continuous mixing for 3 minutes or so before adding the dye and pouring into the channel. I let the resin set up for 3 days or so, then turned the bowl a second time, shearing off all the residue and smoothing the rim with a round nosed scraper. I sanded everything up to 600 and waxed it with EEE wax and eventually polished the rim with plastic polish. I’m super happy with this little bowl despite some crappiness on the bottom. Turning the tenon off is still killing me.