Having done a Chesapeake 17 with scarf joints I am curious re: the general consensus for constructing butt joints. (I've experimented with a butt joint reinforced with a strip of 3" 6oz. glass laid over the joint on both the inside and outside. I then wrapped the whole thing in overhead transparency plastic for a smoother finish. In subsequent, non-scientific testing, the wood failed with no damage to the joint.)

For 4mm okume, what is the "recommended" proper layering/width of joint reinforcement for strong, but reasonably light (i.e., lighter weight cloth on the outside of the joint? Reinforcement block (? width) on the inside in addition to a fiberglass strip?

Inquiring minds want to know...:-)