The laps are fastened with clench nails that function somewhat like rivets all along the overlap. The clench nails go from outside inward, then are bent over slightly onto dome shaped washers called roves (pronounced 'rooves') on the inside.
In the West in modern times, the fastenings are usually bronze. In prior times, both in the West and elsewhere, the lap would have either been sewn with sinew or other strong fibers, or would have been fastened with 'trunnels' (tree nails).
With clinker built boats, the frames are applied afterward and are virtually always steam bent or laminated out of thinner strips, glued in place. In the West, clinker built boats are almost always built over mould frames, though if the frames are laminated, one can create the laminated frames first, attach them to the keel, then begin planking onto the frames.
In the West, small clinker boats are often built upside down, bigger ones upright. The clinker style produces quite a light structure that is very rigid. Clinker style planking is usually reserved for smaller craft. There is no absolute boundary, but presently somewhere around 40 feet on deck is where these Clinker built types give way, and 'Carvel' planking begins to dominate.
Carvel Built Boats: Carvel planking refers to the method of planking where the planks are placed edge to edge onto frames, which are placed first. By this method, the planks are fastened only to the frames.
The 'Pinisi' Method: In the areas surrounding the Indian Ocean, throughout Southeast Asia, and in some of the SW Pacific, the planking is done first, prior to the framing being placed, much as with a clinker built boat, but with the planks placed edge to edge. In order to do this, the planks are "blind edge fastened" to each other.
In centuries past, edge fastening was accomplished by sewing the plank edges together. In current times on both larger and smaller craft, the plank edges are blind edge fastened using wooden dowels, locally called 'passak.'
Throughout these regions, mould frames are not used. Instead the boats are shaped "by eye" following the traditions of the local builders in each area. After the planks are in place, frames are then fitted into the emerging hull shape and fastenings are added to attach the frames to the planks.
The planking on all 'Pinisi' is therefore what Westerners would refer to as "carvel" even though the planking is erected and fastened similarly to the "clinker" style of planking.
Although historically the Pinisi builders used 'passak' (trunnels) exclusively for edge fastening the planks, iron drifts have now become commonplace, placed about every fourth 'passak.' These iron drifts and steel bolts have not replaced 'passak' altogether. 'Passak' are still used at the plank scarfs, for the majority of the plank edge dowels, and for fastening every other plank to the frames. Steel bolts are then used to fasten the remaining intermediate planks. The steel bolts extend all the way through to also fasten the 'Lepe Lepe' (ceiling stringers) inside the frames.
Per the writings of Adrian Horridge, the introduction of metal fastenings took place after the motorization of these vessels. This system is very strong... it makes ultimate sense structurally.
