So I've found enough material here to know that my "Seahorse" is a pretty good imitation sunfish, so I'm loitering here for resources.
The rudder is cracked, and I like a good project so I thought I'd build. But, I'm getting a lot of different ideas: marine plywood, teak, white oak, mohagany, etc.
It's going to be dry sailed so I don't think it's going to be soaked too often.
I have some fiberglass experience as well.
I've seen one project with two plywood halves sandwiched together with foam sprayed inside, and then it was fiberglassed.
My rudder is cracked, but the areas where hardware goes through isn't too bad.
Q: Could I put a few layers of cloth and resin down and re-finish the existing? It would still fit in the hardware.
I'd also need this process for the daggerboard as well--same issues.
Yes. Sand the damaged areas down about 1/16" on each side and fiberglass with fiberglass (or epoxy resin) and fiberglass cloth on both sides. I have done this with several damaged rudder blades and it works fine. Epoxy resin yields more strength but costs more; your choice.
For the wooden board, the tolerance within the daggerboard trunk is relatively tight. Using a straight edge, check the board for warp, and clamp the board firmly against something steel that's straight and unbending while the repair is curing.
But, I don't know what kind of resin-only is be using. I found a sailing supply store nearby. Thought I'd go see. That rudder crack is all the way through. I might feel better with several cloth layers going on. Tolerance there isn't an issue.
As for the dagger board, I'd like to start new. I have a short one that's in great shape but I don't think it's suitable (only protrudes from the hull about a foot). The one that's chipped and cracked is about 45" overall.
I found a marine plywood supplier / hardwood supplier nearby too.
Would a new board suffice with marine varnish on it? Spar varnish?
Yes. Sand the damaged areas down about 1/16" on each side and fiberglass with fiberglass (or epoxy resin) and fiberglass cloth on both sides. I have done this with several damaged rudder blades and it works fine. Epoxy resin yields more strength but costs more; your choice.