We would like to know how is conceived the Dufour 3800 rudder. Ours has tendency to crack and we have injected epoxy and tied it with clams 4 years ago. We then had the recommendation to make a small hole to help water that would freeze in winter, to evacuate it. We did not do it. The treatment made 4 years ago is still efficient à 90% but it started to crack again. Is it dangerous to lose the rudder eventually despite the epoxy treatment when required ? Does somebody has the sketch of a rudder that shows the inside structure. Somebody knows where we have to drill ? Thank you in advance.