Sandaa and Other Lessons

The two most unwelcome words in Japanese for me are "Sandaa oneigaishimasu," (please give me the sander).  Shimojo san is basically limited to working with one hand and so he does an astounding amount of this work with a small electric plane and an angle grinder with a four inch, 80 grit sanding disk.  The last two days we have been shaping the inside of the bottom of the boat and after doing the rough work with the electric plane he reached for his sander to finish it.  The sander produces clouds of sawdust, and having suffered through the hollowing of the planking I decided to jump in and offer to at least smooth the bottom with one of his old hand planes.  Thankfully, he let me go ahead, but still this was followed by four hours of sustained sanding by Shimojo san.

Shimojo san mounted the upright handles on some of his planes to make them a bit easier for him to use one handed, though he said that in the old days Okinawan planes had horizontal handles just like Chinese and South East Asian planes.

I was thinking as I cleaned up that I made a little diorama of Iejima.

This is what we have produced since our first dump run.  I've told Shimojo san we have one boat on the sawhorses and two on the floor.  He thought that was funny.  Today we came in and he told me to start installing huundu along the seams inside the bottom.  He looked at my first one and told me I had made a mistake, that I can't leave any gaps around the huundu (you can see the gap along the right side of the bottom edge).  He hadn't been so concerned with the other ones I did on the outside of the boat, but then I realized that inside the boat any gaps in these fastenings will let rainwater into the bottom.

So I will review again the process of installing the huundu.  No doubt I will learn more details and refinements as time goes on.  Remember, I make these mistakes so YOU don't have to!

Shimojo san marks the plank seam so I know where to layout the huundu.  The seam is so well fitted it can be hard to see.

He's reminded me more than once to make sure my pencil is sharp when I trace the huundu.  Then we use a drill to hog out some material in the center.  Shimojo san depends on the depth of the hole (we have a stop on the drill) to gauge how deep the huundu should be mortised (they go in 1-1/8 inches in the bottom).

The first chisel cuts are just to clear out the bulk of the waste in the center.  The stain is from the oil that Shimojo san insists I dip the chisel in before working.  That is common practice in Japan, though I never see reference to it in the States.  Note that the huundu is far from symmetrical.  Shimojo san cuts them free hand on the bandsaw, finishing the four angled faces with a sharp chisel.  So when you trace them you have to mark them to keep the orientation correct.

My great contribution to Okinawan boat building: I mark the depth of the mortise on the back of my chisel (one inch wide), which I find far easier than searching around for the bottom of the drilled holes.

I chisel further out toward the line, keeping away from the top and bottom edges.  This is why I screwed up the other fastening: I got too close too soon and the fragile top and bottom edges, running with the grain, are easy to crush.

I make four chisel cuts (all straight down) and these are at the final locations.  Note how the cuts taper from to the line at the corners to just inside the line at the waist.  That little bevel is the key to getting the huundu to pull the two planks together.  I still don't touch the top and bottom edges.

Time to clean out the waste with the narrow chisel.  I try NOT to lever against any of the edges of the mortise, especially the top and bottom.

The final cuts clear the top and bottom working very carefully just to the line.

Before hammering them home we bevel the edges going in to make them easier to insert.  This is covered in my earlier two posts on huundu.  You may notice that the labels changed in the photographs. I used several to illustrate this lesson.

Boat Building

I feel like some of my recent posts have been digressions from the work at hand that it was time I got back to the boat building.  It's been a productive week in the shop, and with this posting I will try to catch everyone up on the last couple of week's work.

In an email today another blog writer pointed out that the sabani turns the log canoe on its head, starting with the side planking and then adding the bottom instead of the other way around.  He's got a good point and a great blog including an old posting about sabani:

http://indigenousboats.blogspot.com/2008/08/did-sabani-show-up-at-olympics.html

Once we finished bending the side planking, a process that took three days of pouring hot water on the plank set-up while we tightened large turnbuckles that we temporarily bolted through the planks.  We then firmly fixed the side assembly to sawhorses, braced it to the floor (though it is not that firmly, so we have had to be careful), and then dropped the bottom timbers on top, fitting them one at a time.  The first was the largest, the center timber, followed by one side then another.  The chainfall was absolutely essential for this.

What surprised me was how slowly this process went, and how we incrementally fitted each piece.  All three pieces came off the boat and to the horses for trimming about twenty times.  But when they were finally fitted (to Shimojo san's standards) then we brought all three off the boat and set the bottom up on its side on our sawhorses.  The time had come to do the final fit of the center seams, and for this we employed a technique that is used by boat builders across Japan: surinoko.  It is also called suriawase and tosunoko (tosu mean to pierce).  It involves running a saw blade (noko) through the seam to reconcile the opposing edges (awaseru or suru).

One of the big differences between the way that Shimojo san builds boats and three of my other teachers (my first teacher was basically a barrel maker and used a different technique entirely) is that he largely fits pieces with the plane (like Western boat builders do).  My other teachers would go from a rough cut with a circular saw and do all the further fitting of planking by suriawase.  My other teachers would spend half a day fitting a single seam the length of the boat.  Shimojo san believes that the use of the saw is for the final fitting only, and he's quite critical of the way boat builders in the rest of Japan work.  His argument is that it takes too long using just surinoko (which isn't born out by how long it took us to fit these timbers), and he argues that multiple passes eventually starts to round the corners of the planks edges (he's got a point there).   If you click on this photo, you should be able to see clearly how the kerf of the saw creates two parallel edges.

We had to brace all the pieces to the wall, given their weight, and the need to hold them firmly in place while we sawed.  Shimojo san has some great home made tools, basically old saw blades that he broke off and filed smooth.  These are wedges that hold the seam slightly open so we can run the saw through (my other teachers used wooden wedges or caulking irons, but I have to say that Shimojo san's use of old saws here is brilliant).  You work these wedges on either side of the saw, as needed, to keep your saw from being pinched.

The sawing motion is VERY important.  Essentially the kerf of the saw, in passing between the two pieces, is creating two parallel edges.  In our case both the side pieces had changed shape as we removed material.  They were tight at the ends leaving a gap in the middle.  We snapped in inkline and carefully planed the edges straight again, but still when we put them together the ends were tighter than the middle.  We did about three passes with the saw at either end and one long, slow pass down the middle and Shimojo san called it done.

His son explained to me that while sawdust is coming out you must move very slowly down the seam, even if there is very little resistance, because the saw teeth need to cut closely spaced kerfs.  If you move fast then you don't create the "rubbed" surface that is considered ideal.  Shimojo san's son used a good metaphor when he told me it was like rubbing glass lenses.  Here are some shots showing what our finished surfaces looked like.  Remember that these were planed smooth when we started.

We then glued these timbers together using a glue common here in Japan called Bondo (no, it's not an auto body product).  Shimojo san said traditionally he never used glue (he never had any).  He said that with this boat he is concerned because the material didn't have the full year to dry that he likes, and he thinks that the glue is essential to minimize wood movement.  We installed dovetail keys in the seams on the outside face, spaced one foot on center, along with bamboo nails (see earlier posts about these fastenings).

We turned the bottom over and for the last two days we have been doing the final shaping of the inside.  Tomorrow we will be putting dovetail keys on the inside face and then putting the bottom back on the boat.  Our final fitting will involved doing surinoko all along the seam between the bottom and side planking.

By the way, the bottom is about three inches thick throughout, and my guess is it weighs 400-500 pounds.  I also think it is going to represent perhaps 50% of the weight of the final boat.  A three inch thick bottom explains why sabani lasted the lifetime of their owners but also provided the stability needed for a hull twenty-five feet long and less than five feet wide....

Tankobune

Legacies of the War.


There are some interesting legacies to the War that relate to fishing and boat building here in Okinawa.  Before I arrived Shimojo san had roughed out a bailer for our boat.  He used Okinawan pine and we are letting it dry before doing the final carving.

He told me though that the craft of making these bailers all but disappeared because after the War fishermen gathered American helmets and used those instead.

By far one of the most interesting uses of salvaged materials is the "tankobune" (tank boat) which were made from US Air Force aluminum drop fuel tanks, which must have rained down on Okinawa in the thousands.  In addition to being used as water tanks (islanders collect rainwater from their roofs), fishermen were soon cutting them in half and making boats out of them.  Here's one in the local museum.

They are about eleven feet long and one man I met told me that the island's airport had a squadron of Republic P-47 Thunderbolts after the War, so he thinks most of Iejima's tankobune were from P-47s.  Tankobune were, of course, not for the high seas, and were used here mainly fishing for octopus, which the fisherman caught with a sight glass and spears, working close to shore.

Shimojo san told me that in his machine shop he was the first person to put an engine in a tankobune.  He installed small, one cylinder gasoline engines in them.  I asked how long these boats were used here and was told that they were common up until about twenty or thirty years ago, but tonight a visitor to my guest house insisted that he knew someone locally who used a tankobune until just a year or so ago.  I couldn't help but ask if I could meet this person and see his boat, and tonight I got my chance.

Oshiro san is ninety-four years old and has had his tankobune for about sixty years.  He was a tobacco farmer and a part-time fisherman, going after octopus as well as other fish.  He and his wife were saying how hard life was after the War, "lots of kids and no money" and his wife added, "When you have no work its good for making babies."  I've noticed that post-War families here were big ("baby boom" is a phrase that everyone recognizes).  But the most amazing thing was learning that Oshiro san last took his tankobune out just two years ago, when he was ninety-two!  You have to come to rural Japan, and see how hard the elderly still work in the fields and in the sea, to believe it.  And you can be a militant wooden boat fanatic but you have to admit that tankobune are very kawaii, or cute.

 A man after my own heart he also had an unpanki, which means "transport machine" and is the precursor to the truck here in rural Japan.

December 7th

December 7th

Today is December 7th, and news media in America will be remembering the anniversary of the attack on Pearl Harbor (there is no mention of it in the news media here).  By chance yesterday I visited a cave that is considered a famous site on the island.  I misunderstood the sign and this morning at break when I asked about it, Mrs. Shimojo told me the cave's significance is because islanders sheltered there during the Battle of Iejima.

This started a conversation about the War in more detail that I had heard before.  Shimojo san told me that the Japanese Army was taking boys as young as 13 to build defences.  His family fled the island for the main island and he told me that his family lived in the mountains for three months.

Today I visited the local museum at the port and the exhibits featured some USMC photos of the invasion.

The same mountain today.

The photo of the civilian refugees is revealing.  Last week Shimojo san was telling me about the "good old days" and he said that when he watches historical dramas on TV he says, "We lived liked that."  He told me that the island didn't get electricity until the early 1960's.  Before that they cooked with firewood.

Tonight I rode a bicycle around the island and saw the old airfield where the official letter of surrender from the Emperor was flown by three Japanese bombers and then carried by US aircraft to MacArthur's headquarters. I found a building left as is from the battle as a war memorial.  There is also a memorial to the civilians killed on Iejima, with what looks like a couple of thousand names on it.  Shimojo san told me that the American soldiers were buried at one end of the island and later their bodies were taken away.

I also visited the memorial to Ernie Pyle, the famous war correspondent who was killed here on Iejima.

The memorial's message is simple and moving.  The statement from the islanders is similarly compelling.  Okinawa had been annexed by Japan, and from many references Shimojo san has made he considers himself Okinawan and not Japanese.  As for the War, many Okinawans feel that the War was not theirs, but they found their homes become a battlefield.  And after the War Okinawa was essentially annexed by the US.  Thousands of Okinawans had their land seized for US bases, and these seizures increased with the Vietnam War.  Up to half of Iejima at one time was off limits to the islanders, and still a quarter of the island is a US base.  I found this old marker on my bike ride today.

Today Shimojo san finished talking by telling me that while his oldest brother is in his 90's and lives nearby, two other older brothers were killed serving in the Japanese Army.  At that he fell silent, and after a minute or so he got up and we went back to work.

Questions and Answers

This posting is my longest yet, but I hope you will bear with me.  

One of the mysteries of the last two weeks has been why we've worked from such huge pieces of wood, and secondly why we have taken such incremental amounts off them in trimming pieces to fit.  It just has seemed like an ungodly amount of work to shape and trim the three pieces that compose the soko, or bottom of our boat.  

Of course my primary role here is as a researcher, and in that guise it is my job to record how my teacher designs and builds his boats.  I have had a lot of questions lately about why Shimojo san does some of the things he does, but I have to be careful because it's certainly NOT my job to tell him how to build a boat (given that he is eighty years old, and has built more than a hundred boats over the last sixty years, this would be beyond presumptuous).  But when his methods seem strange then I feel I need to carefully prod him to find out why he is doing things the way he is, even when the inference is clear that I think there is a better way.  

Here I am roughing out our final piece of wood for the bottom, using an electric chainsaw.  The other picture shows me taking an inch off the straight edge with the beam saw.  Although it took half an hour to chainsaw the length of this eighteen foot plank, I was very grateful that we at least got rid of this much material at once.  That is because we've been using the electric plane again and again to remove vast amounts of material.  Shimojo san has two bandsaws, and I asked him if we could use one of them to saw this material.  "No," he said, "that's bad."  Lot's of time the answer to why in Japan has been, "Because that's how it's done."  It was one of those moments where I didn't feel it was appropriate to press him for a reason, so half an hour later I finally had the thing chopped through.  

Here is a shot of the bottom of our boat, with the center and one side piece at their basic final dimensions, and the last side piece dropped into place for the first time.  Remember, I had just cut almost a two inch thick slab off the curved side of that thing, and another inch off the straight edge, and its still huge compared to the rest of the bottom.  

So that was the next big question: why do we painstakingly plane down these timbers to a final fit?  Twenty times we moved the center timber off the boat and to the horses for planing, and back.  Twenty times we moved the first side timber for fitting.  We are two days into it and ready for our ninth pass on the final timber as I write this.  When we are done it will have been almost two weeks that we have been working on just these three pieces.  

One thought I had today was that Shimojo san told me that a sabani, well taken care of, lasted the lifetime of its owner, so applying a cost benefit analysis, taking an extra week or two to build is really nothing compared to, let's say, a sixty year life of the product (one boat at the sabani race I watched was fifty years old).  

The other thing that prevents me from rushing right in and asking Shimojo pointed questions about his methods is my second role as an apprentice.  In Japan the apprentice system is well within the collective cultural memory.  And a deshi (apprentice) lives and works under very strict cultural norms.  I've had some very interesting moments with my other teachers in Japan when I tried to suggest something, and I frankly regret, in most cases, having ever raised any of my bright ideas.  It is simply NOT the apprentice's place to question or make suggestions to the master, and the master is certainly under no obligation to explain himself.  A westerner's first take on this would probably be resentment, followed by rebellion.  Perhaps if you have studied martial arts you understand that demanding humility and obedience is actually an integral part of the learning process.  

Shimojo san did not himself apprentice with a boat builder.  He taught himself, and I realize that he treats me like more of an equal than any of my other teachers.  He's encouraged me to copy all of his drawings and patterns (we are lucky to have them; he told me that he always worked from memory alone until a few years ago, when he realized he was forgetting things and made drawings of five types of his sabani), and he says he hopes I will go back to America and build a sabani.

An answer:

Today I was taken by surprise when we were lying under the boat together marking the timber (yet again), when Shimojo san turned to me and said, "You're smart.  You are wondering why we are taking so long to do this."  I said that I was wondering, and I asked him why he didn't measure the timbers and cut them nearly to shape right from the start.  He said, "I used to do this whole bottom in three or four days.  I would maybe make three passes with the chainsaw then a final fit with the plane.  But since my accident I can't use a chainsaw so the only tool I can use is the power plane." He added, "I couldn't go to Miyazaki to supervise the milling of the wood and it came here too big."   About the bandsaw he said, "I can't do that one-handed, that's dangerous."  So what it boils down to is that he basically has to do all his work one-handed, which means he only has the power plane (or has me use the electric chainsaw, but he is not ready to trust me to make finish cuts with it).  As for the time factor, I think that to Shimojo san its just not a concern.  He's eighty years old and likes building boats (we work seven days a week) and doesn't have to worry about when they get finished.  

Ironically this same morning his neighbor and I were chatting before work and he said, "Shimojo san will always build boats.  That's all he wants to do.  There is no stopping him."

Huundu Two

Okay, my last posting isn't even cold yet and I need to write a bit more about the butterfly fastenings we are using.  Today my teacher put three huundu in the seam aft where the two side planks come together. As an aside, he told me that this bit of design is one of his signatures.  I guess in other sabani the bottom timbers run all the way to the base of the transom, but when we bent the planking we pinched the side planks together over about a 16 inch seam aft.  It is kind of sexy to create that narrow edge under the boat aft....

The photo above shows the fastenings and pot of oil that Shimojo san dips the huundu in before hammering them home.

Here's a look at that seam.  At the bottom of the photo you can see the base of the transom (an inverted triangle).  Two of the huundu have been installed and the mortise for the final one has been cut.  Note how the outer edges of the huundu are right at the edge of the planking, which is falling away at a sharp angle.  Shimojo san stressed that the width of the mortise needs to be generous (not a gap, but not tight either) otherwise the fastening will split the plank.

But the really important thing is that the undercut of the mortise, which makes the huundu tight, does NOT run from the outer corners to the waist like on our other huundu.  Instead it starts from the middle of the sloping side and runs to the waist.  So in effect these huundu don't have quite the squeezing power, but this ensures that they don't stress the edge of the plank and split them.  These are the details that make my mind race (and sometimes tax my Japanese) when I am doing this kind of research.

I also forgot to mention in my last blog posting that you chamfer all the edges of the huundu in order to help it get started in the mortise.  We use a knife or a chisel and just quickly chamfer all the edges.

Once again we used bamboo nails with the huundu.  Note how the two enter from alternate sides.  They get oiled as well and then all the fastenings get cut flush.

A shot of a bamboo nail with the shaku scale.  It is seven sun, three bu long, just under nine inches.  The node section in the bamboo creates the "head" of the nail.  It is mosodake (moso bamboo) from the mainland.  Shimojo san says that Okinawan bamboo is poor quality.

Huundu

It's about time that I blogged about one of the most important techniques used in building traditional sabani: the dovetail key fastenings used to hold the boat together.  Except for some trim on the gunwales, the boat we are building will be held together entirely with these wooden keys and bamboo nails.  Called "huundu" in the Okinawan dialect (and no one yet can tell me the etymology of the word) I have found these types of fastenings in a few other places in Japan, including river boats of the Mogami and Agano Rivers, and a type of semi dugout built on the Noto Peninsula.  All these places are on the Japan Sea but far from Okinawa.  In some ways this project's genesis was in my desire to learn this technique.  I knew the last boat builder of the Agano River and he agreed to teach me, but he became to old and ill to work, so I began thinking of where else I could go and learn this.  Here I am, years later, in Okinawa.

As you can see these are mass produced.  They are made of hardwood while the planking or our boat is softwood (cedar).  Each one is a little bit different so when we lay them out across a plank seam we carefully traces the edge and number them.  They need to be used in the order they are laid out.

My teacher likes to use a drill set to the proper depth to hog out some of the material.  The base of the drill bit is also a guide to carving the depth of the mortise.  These are set inside and outside the boat, they are spaced at one shaku (one foot) intervals with an even stagger between inside and outside.  We had to take into account areas where we were hollowing the planking; In those places where the planking is thin, there is a 1/4 inch of material left between the base of the huun du and the other side of the plank.

The key to cutting the mortise for them is to cut to the line at the top and bottom, but then as you approach the narrow waist of the huundu stay just a millimeter inside the line.  It is in the middle that you want the mortise to be just a little tight.  Also, the sides of the mortise are square to the face of the planking, just like the sides of the huun du.  You can just see my pencil line in the photo.

Once the mortise is finished we dip the huun du in oil (traditionally shark liver oil, now fry oil) and using a mallet drive it into the mortise.  The nature of our undercut makes the huundu pull the two planks tightly together.

In between the huundu we also drilled holes at a very shallow angle and nailed in long bamboo nails.  The drill bit was slightly undersized and you don't drive these nails more than about 1/4" into the wood once they reach the bottom of the hole.  Otherwise they are likely to snap off.  When we are all done we saw off the excess material, plane and sand the surface.

Here is what they look like on a finished boat.

And by the way, on the Agano River these fastenings are called "chigiri," or in the local dialect "chikkin."  They are also called zuzumi, after the two headed Japanese drum which they resemble.  They are well known to furniture makers the world over, as butterfly keys or dovetail keys.