Building the Acorn Dinghy in Japan

I am a Japanese amateur boat builder who lives in Tokyo. So far, I have completed a 15' foot wood strip canoe, the model is called Bob’s Special. So as a boat builder I am quite a novice. Last year-end, by chance, I was asked to build a lapstrake sailing boat for my colleague, it is the 10’ 2” long Acorn Dinghy. Despite my canoe building experience, even though this is not a first time project, his request is a challenging one which I accepted.

To proceed with this project, first I procured a plan from WoodenBoat shop. But there were still a couple of problems I had to solve, which includes: how to build the glued lapstrake, finding a suitable space where I can build the boat, and the lumber (plywood or solid wood) specified in the plan by Iain Oughtred.

In terms of how to build, I was able to solve it by reading the book, “How to Build Glued-Lapstrake Wooden Boats”, written by John Brooks (get it here). This book describes comprehensively the glued lapstrake boat building process, and especially helped me to understand about spiling the strakes. Besides, I was pushed to make a building jig in accordance with John’s way, which is a heavy-duty construction so that I can even sit on the boat upside down on the building jig when planing the keel or making an opening for the dagger board.

About the suitable space, fortunately I was able to borrow a workshop in the local junior high school, where I have been teaching a woodworking workshop to the pupils and their parents on the first Saturday every month as a volunteer. With such a relationship, the director of the school has given me permission to set up a building jig in their workshop and to use it freely every weekend. I believe that this is a very rare and lucky case.

With regards to the boat building materials, except for the marine grade plywood, so far I have not had any difficulties purchasing. In Japan there are many big manufacturers of epoxy resin used in the electronics industry, but none specified for boat building. However, since there are a few shops that handle American epoxy used for boat building, I purchase from one at a reasonable price compared to the US market.

For the planking stock, the plan specifies that the highest marine grade plywood shall be used for glued lapstrake building. But I was not aware which lumber yard or shop handles such a thing when I began this project. So I have decided to build my Acorn the traditional way using solid lumber and copper rivets. To do this, I have been able to purchase four pieces of Nobel fir boards at an inexpensive price, it is 47mm thick x 230 mm wide x 4 meters long with straight grain and defect free. I am going to re-saw these into four pieces of 8 mm thick planking stock each, using a table-saw.

At the moment, I am struggling with making the full frames. Anyway, I am going to show my Acorn building process in my website step by step, please browse and comment about it if you wish.

http://www012.upp.so-net.ne.jp/kane-toku/acorn_building.html

by Yasushi Nakagawa, Tokio, Japan - October 2007
e-mail: nakagawa at ra2 dot so-net.ne.jp