Assembling the Backbone

Had to start today cutting out some bad knots in the bottom near the stern and plugging them.

Only one of my teachers ever bothered to glue his plugs.  When the grain runs at 90 degrees to the plank the plug will generally stay tight because it swells at right angles to the planking.  Also, I learned to cut the plugs slightly oversized and pound their edges with a hammer to compress them.  Done right they go in with a tight fit, expand and they will not come out.

I had to use a curved-sole plane to round the inside of the bottom, aft.  The original boats shows this shaping only near the transom.  Once I had a good fit with the transom at the proper bevel I glued and fastened it with large wire nails through the bottom.  This is how the original was assembled.

Interesting technique I learned from my second teacher in Urayasu.  In order to line up the bow I fastened the ink line on the centerline of the bow and took wraps around the two legs of my square.

The ink line was then pulled tight and lined up with the centerline on the bottom, aft.

I swiveled the bow until the heel of the square hung just over the centerline of the bottom at its forward edge.  

At that point I knew the two pieces were lined up and I traced the shape of the bottom onto the bow.

Its a rough fit but the next step is using the saw to get the final fit.  If a simple butt joint in boatbuilding scares you, you are not alone...  Stay tuned, as I've learned a few tricks here.

Once the bow is fit and fastened its time for the side planking.

Houses and Boats

I took a new little back street to work this morning and found four traditional houses built in the local style.  These are great to find and actually many of them are empty.  One of the women at the Center rents a traditional house, which she calls a nagaya, for $1,000 a year.  You got that right, less than $100 a month.  These places are basically considered worthless here in Japan...

Note: since first posting this I have learned that a nagaya is the name for a row of houses that share the same roofline and have very narrow frontage.  In the old days taxes were calculated by frontage and you can find some impossibly narrow homes in Japan.  Even modern homes, as architects have to deal with old lots in urban areas.  Its really something to get out into the countryside, where one suddenly finds huge old farmhouses.

I am not writing from much expertise but that first floor looks like it was a business to me, with living quarters upstairs.  Even today many or most Mom and Pop businesses have the residences in the back.

Porch roof eave detail.

Main roof beam ends covered in copper.

The NPO I am working for started in part of this old soy sauce factory.  This is an amazing complex of old buildings.  The NPO occupied the building on the left.  I've been told there are some huge old wooden barrels and tubs inside, which I am hoping to get a look at.

The NPO restored the kura, or fireproof storehouse, a plastered building coated with tin.  It was a very cool space.

Back at the new center I assembled the two bow planks today.

I've never fitted planks before at an angle.  I don't even know if the original boatbuilders did it this way but its an educated guess.  Most readers of this blog would fit two boat planks using a plane but in Japan all planks are fit using a series of saws.

To figure out the edge-nailing I drew it full size.  This would be called lofting in the West.  In Japan I've never seen a traditional boatbuilder loft anything full size; all the information is scaled from a 1/10th drawing or just done from experience and memory.  At first I thought I would curve the nails, but then I realized a nail curved back would not pass through the mortise, so I did the layout for straight nails.

I had to offset the holes from center quite a bit, and angle my chisel when piloting the holes into the mortises, plus make sure I got the offset and angle right on the other plank.

This tool is for cleaning out the holes to a consistent width.

You probably want to click on this photo to get a close look at the end of the chisel.

The bow planks nailed together, three nails from one side, two from the other.  

A Plug for Visitors

Today I finished the bottom of the boat, cutting off all the plugs with an adze and planing both sides by hand.  A bit tricky because the two outer planks on the bottom are at a slight angle, giving the bottom a bit of curve in cross-section.

When the plugs are installed tight they create a interesting pattern in the planking.

Craftspeople working in front of the public is a pretty rare thing in Japan, and sometimes I think the audience doesn't quite know how to handle themselves.  I say hello (in Japanese) to most people and most give me a polite bow in return and say nothing.  I am almost never asked a question.  The great exception are elderly people.  I feel extraordinarily lucky that my work has taken me to the deepest rural areas of Japan, because the people there are so earthy.  Already in this project elderly men and women have walked right into my shop to pick up and study my tools, and engage me in animated conversations.  The other day an elderly carpenter told me my chisel wasn't sharp enough.  Today a woman said her father built these boats decades ago.  Yesterday an 85-year old pointed out that boatbuilders mixed wheat flour in their lacquer to put between the planks (a museum book confirms that fact).

Last night we met the man on the left at an antique shop.  He led me off to another store to look at some old chisels.  Today he appeared with a large bag of carving tools.

These are his practice carvings.

He said carving hands and feet are beginner's projects, and the book he brought was an excellent how-to guide to carving, despite being in Japanese, richly illustrated and photographed.

He had four sets of carving tools.  When he was done showing me this stuff he announced he was giving it all to me!  I protested but he insisted, saying he was done with carving and he absolutely wanted me to have it all, book, chisels, two new sharpening stones AND his carvings.

The bottom is normally called the shiki, or soko.  It turns out here in Himi rice-field boats' bottoms are called chiyou.

Next up is making the bow, which consists of two planks edge-nailed at a 20 degree angle.

I met this woman at her fish market when I stopped to ask directions one of our first days here.  She's given us fish and today she stopped by to say hello.  I give her a wave on my way to work each morning.  She is the definition of the word "radiant."

Fastening the Bottom

I finally got the four planks comprising the bottom fastened together today.  I say "finally" because I can well imagine in the old days someone building one of these boats in a week, which is how long we've been here.  But there has been lots of talking to visitors, a long interview with three reporters the other day, and just time spent sharpening up my tools and getting the lay of the land.

I lay out a center point where each edge-nail will go.

Making the pilot hole with the chisel first I make a cut one side of the line...

...then a cut on the other side...

...then wedge out a little square of wood.

This leaves a rectangular hole the same cross-section as the nail.  Then I pound the chisel in, rocking it back and forth a bit, and cut a hole a bit shallower than the nail.

Pilot holes down the edge of a plank.

A view of a pilot hole, with a nail mortise below it for the adjacent plank.

Today's papers had stories about me.

Given how long the interviews lasted I am surprised by how short the articles are, but the free advertising should be good for business, as Earle Brockway always said.

The local boatbuilder dropped off some waterproof glue for me.  Its a two-part deal with a small bottle of liquid accelerant.

I had to carefully prop one edge of the outer planks to hold their slight bevel while I nail.  

The last step is pounding the edge with a hammer, called kigoroshi.  You can see one compresses just the center of the edge, leaving the corners untouched.  The idea is when the planks are fastened the unsupported corners will collapse a bit and later when the wood fibers in the center spring back it makes for a super tight fit.

Glue spread on the plank edge.  In the old days boatbuilders used raw lacquer, and in this area raw lacquer thickened with wheat flour (today an 85-year old man told me that).  Then everything is edge-nailed together.

I cut plugs for the nail mortises, using my original pattern to lay them out.

I trim them so they don't quite fit, which means I have to hammer them home, ensuring a tight fit.  My teachers did not use patterns for this work; they could chisel mortises that were all identical working by eye, and they could cut plugs using just a large chisel.  I have nowhere near that level of experience and never will.

I cut the plugs using a circular saw...

Then split them to get two plugs.

With a plane, saw, and chisel I fit them all.

Because the grain of the plugs runs at right angles to the planking if the plugs are fit tight they won't come out, but I am gluing them regardless.  Its actually not a waterproof glue but it should keep them stuck in there.  You have to drive them in carefully, putting pressure on the end and hammering down at an angle to keep the heel of the plug tight to the mortise.

My Tokyo teacher used to trim them off with an adze so I will too.  The hardest part is making sure that feather edge of the plug (to the left) is down tight to the base of the mortise.  Otherwise when you plane it (tomorrow) it doesn't look clean.