Material; cotton roving, mallet, caulking iron.
The seams between planks are filled with cotton roving. The cotton is pounded in by hand with a mallet and caulking iron. This will form a base for the seam compound.
Rhythm hit, ruck, hit, ruck, etc. 3,600 an hour.
Caulking irons; the first one used has a sharper finer edge, the second one more flat.
When I went to China, I saw wooden boat builders there using a material that appeared similar to excelsior for the same purpose. It was a plant based material, but due to translation difficulty I did not find out what kind. They also used a gray, very sticky, plant-based substance for seam compound. They were working on a traditional dragon boat, built to carry 22 paddlers & a drum.For sustainability, although cotton has a high cost of production for this purpose, the shorter staple, poorer quality could be substituted since it does not show as in a garment.