Monday, December 21, 2009
Finishing the Hull
Things have happened quickly the last few days on the boat. In the interests of time I will just post photos from the last three days and throw captions under them. My apologies for the brevity but remember, you should always be able to click on a photo and enlarge it. Take a look around.
We fit the gwa gwa at either end using the suri noko method, after planing to the best fit possible, running a saw through the seam several times to make the fit perfect.
This is new for readers of this blog: The endgrain joint of the gwa gwa, which is a very shallow V-shape, is pounded with a hammer, compressing the fibers so that after the pieces are put together these fibers will expand and make the joint absolutely watertight. This method is used in other ways throughout Japan. I have been wondering how we were going to handle this large endgrain joint. Shimojo san pounded this to a point where the cedar had been compressed at least 1/8". He worked a little more gently near the edges so not to split them. Then he very lightly planed the high spots and we put the piece in place and did several more passes with the saw in the joint.
Helping and researching at the same time: I brace the gwa gwa while Shimojo san pounds the endgrain while I take notes on this method.
Shimojo san said that in the old days, the sabani's planking came together along the bottom near the bow. He said that the gwa gwa was much smaller and the seam ran level (as indicated by the batten). Shimojo san said that this plank seam underneath the bow was very weak (but partly the result of very wide planking material). The current form evolved and Shimojo san believes it greatly improves the boat.
Planing the forward gwa gwa to a rough shape.
The gwa gwa dogged down with staples. We've glued it to the planking (even glued the endgrain). Then we installed huundu and bamboo nails.
A detail of the huundu and nails holding the gwa gwa aft.
As of yesterday, awaiting final sanding.
Spent over half the day sanding the hull, 60 grit followed by 100 grit.
In the old days it was shark liver oil, which I am told you could smell at a great distance (and it didn't smell good). Now we are using soybean oil, the kind used for cooking tempura. We put a generous amount on the boat at the end of the day today. Shimojo san said it could soak up plenty. I am not sure if we will put more on tomorrow or not, because we are turning the hull over tomorrow. Seems that an oily boat would not be a good candidate for rolling over, but I will find out.