I have to replace the plywood rudder head
on my 17 ft, AFC 2+2 'microcruiser' sailboat. The original 30 yr old rudder head
was made of one thickness of 1/2" plywood
on either side of a 1/4" thick piece. One, 1/2 " side of the original recently snapped off about 6 inches above the kick up rudder pivot bolt. An examination of the remains showed that the head of the pivot bolt pulled through the 1/2 piece on one side and the unsupported piece on the other side failed. (My fault for not adding a large washer behind the bolt head)
I'm trying to decide whether to build the replacement out of plywood or to use 1/2" sheets
of KingStarboard. I'm aware that at least one company manufactures foiled replacement rudders out of HDPE. Some sailors have reported that the 1+" rudder blades are a bit bendy. I've also seen a reference to snapped rudder blades. I'm sure Starboard is great for many marine
projects, but I'm concerned that it might not be strong/stiff enough for this application. The aluminum
rudder blade would obviously put a considerable load on the insides of the rudder head.
The dimensions of the rudder head are 12 inches wide by 24 inches tall.