I’ve been watching John Coker’s build tutorials on YouTube, and something is really bugging me: In every case, I see centering rings, fins, etc. being epoxied together, but with fillets only - there is no epoxy applied between the mating surfaces. (such as the inside/outside of the centering rings, or the roots of fins.) I only see epoxy fillets being made. I’m not going to claim extensive amount of epoxy experience, but I was taught that fillets are used to supplement the joint between the mating surfaces — and fillets aren’t supposed to be the only thing used to bond. So what am I missing? I get the feeling I don’t understand something properly.