It ain't the
Posted by: CEWilson on Nov-06-12 12:29 PM (EST)
Robustness of the bolts that we're worried about. Anyone breaking two 10-24s in tension assuming all weight on one seat bar, is too heavy to get in/out of a canoe.
The consideration is the size hole bored in the inwale. This is particularly the case with wood rails, the inwale normally 3/4 X 3/4 stock with the rabbet removed. A 1/4 hole, bored 17/64 comprises over a third of the inwale. Hence the move to # 10, nominally 3/16 in; leaves more wood and weighs less too.