Busted Bowrail Welds

[rondds]

my bowrail is welded at all junction points. each stancion is welded from beneath to a round deckplate, and that deckplate is thru-bolted into the deck, with a circular aluminum backing plate. here is my problem - i am about to replace my THIRD bowrail deckplate connector b/c of a failed weld. i think the culprit is the tremendous amount of force that the ribs of my fisher cover frame puts on the rail. everyone i know with a fisher cover has constructed the same type of frame. a 4" pvc "spine" with vertical supports spaced evenly, and 1 1/2" pvc ribs attached to the bowrail. but i am the only bridge boat i know of that doesnt shrinkwrap. none of my friends with dancers or similar type maxums, etc. have this problem, simply b/c they are so much lower to the ground and pose so much less resistance to the wicked winter winds. i dont mind replacing these connections but they are an absolute BEAR to get to. has anyone had any experience with this type of failure? anyone have any ideas how to support the ribs without involving the bowrail?