To use gage # 4 while the double layered bowl still attached to the chuck is tricky business, because the gage has to sit on the bowl passing the centre point. The chuck will prevent that of happening . Instead of pulling the bowl off the chuck to do this, I came up with this idea.
Cut an arch, wider than your chuck, in a piece of timber and glue it vertically on the bottom edge of the gage AND THEN cut off the connected piece of the gage. So, now, you can use the gage so many times, keeping the bowl on the chuck until you finish all other stepts.
Cutting the connected piece AFTER gluing the bridge is very important to prevent any movement and changing in gage shape. Good luck again.
-- Sam Shakouri / CREATING WONDERS WITH WOOD.....Sydney,Australia....