Some 30 yrs back I made a set of frame+panel white oak carriage doors. As I should have expected, the bottom panel groove held water, and the doors are now rotting there. It seems fixable with just a few insets, but is there an accepted way of dealing with this in frame and panel doors exposed to rain? Or are frame and panel doors just a bad idea outdoors? The owner wanted the doors unfinished, so I sealed them with Thomson's waterseal, which has been periodically reapplied. They've aged very well, with the above exception.