Tuesday, June 30, 2009

It has been almost two weeks

Sunday the 21st, Eric, Elias (Eric’s friend and number one apprentice) and I traveled a short distance north on a very torn up, bone rattlingly rutted highway to a beautiful mountaintop pineapple farm. A taxi wound around and around the low, lush mountainside until we stopped at a short, dirt road. It turns out Adjei, one of the apprentices lives here with his family on the weekends. The feeling is intimate and expansive at the same time. Adjei’s family lives in a complex of small buildings. The patriarch is Mr. Klu, a pleasant man who has a huge smile and ruemy, thoughtful eyes. He greeted us and began to show us around. Behind his house was dense with foliage, a school was being built across a pasture and then back down the dirt road we walked off, machete in hand, toward the pineapple farm. This is when things started getting expansive. As far off in the distance as you could see to the west the mountain continued on as part of a chain of mountains. Huge trees stood as sentinels to the farm sections. In fact when I asked about a smaller bushy tree that looked like it had palm fronds growing all over it I was told that it was a tree used by farmers to mark the corners of their plots because the tree never dies. One can to cut it down, push it over, or pull it up and as long as some root material stays in the ground the tree will regenerate.

Saw starkly present red earth mounds created by wood eating red ants (not termites), big black splotches of black ants that create an open nest around an elbow or crook of a huge branch high up in the massive trees, the jointed stalks of cassava plants (the root of which is a starchy staple in Ghanaian food), and the thick co-mingling of sword shape leaves of pineapple with their prickly fruit and flower nestled into openings of leaves.

Mr. Klu pulled off several fruit and trimmed off the top flowers and we walked back anticipating the taste of fresh pineapple. After walking back along the ridge of the mountain taking in the scene in reverse, we sat comfortably on Mr. Klu’s porch and gorged on the sweetest pineapple I have ever tasted. And later had banku, which is a starchy paste made of cassava root and corn meal pounded together and eaten with a pepper spicy stew of goat meat and tomato paste and vegetables. Adjei was interested in the running shoes I had on so I told him if he brought pineapple to the workshop every week they were his at the end of my stay.

This week I worked much more in the shop. I have built and shaped the fuselage of an airplane coffin, contracted some sort of rash (cause unknown), also contracted a cold, learned to find my way to breakfast and the shop by myself in a taxi, and eaten a lot more banku and foo foo (very spicy, very yummy).

Imagine a very thick, six foot cigar made up of 50 to 60 pieces all hand shaped and planed on edge and end to create a loosely coopered, angular barrel. This the plane fuselage. Coopering is the skill of making the staves of a barrel. With a barrel all pieces are approximately the same. Each edge is beveled (an angle less then 90 degrees which allows the required amount of pieces to be put tightly together creating a polygon) so that when the staves are nestled together inside metal hoops the pieces fit neatly together in a rough circle, each edge touching completely the next edge. Because the staves are straight and are wider at the center and narrower at the ends, the only place they touch when first put together are at one end inside the first metal hoop holding the staves against a round wooden end. Now the inside of the staves are heated, traditionally with a fire. This makes the wood pliable and allows it to be bent. A second metal hoop, a bit larger, is hammered along the outside of the staves away from the first hoop as the staves soften from the heat and begin to bend. As the hoop travels along it forces the wood to come together, closing up tightly the spaces between the beveled edges. Because the staves are wider at the middle the barrel diameter gets wider as the hoop forces the staves together. Once the second hoop travels maybe a third of the way along the staves a similar size third hoop is forced over the opposite ends of the staves, further bringing the staves tightly together. Now this hoop is driven a third of the way neatly bringing most of the length of the staves together. The fourth and last hoop, the same size as the first, is forced on and brings home tightly the rest of the edges and the end of the staves around the other end piece. The 'barrel' shape, which necessitates narrow ended/wide middle staves, comes from the long ago discovered mechanical advantage that wood pressing in on wood under the tension of bending forces the edges to become close to leak proof. The final tightening of the joints, with the desired impermeability, comes when each stave absorbs liquid and expands, using powerful hydraulic pressure against the metal hoops and in turn one stave against the other. Once the staves become dry again they will shrink and the barrel will leak.

The staves and therefore the volume making structure that make up the airplane coffin are created a bit differently then a true barrel. There are no hoops holding the staves together from the outside, and the beveling is quite different, as well. To hold each piece to the next, nails are driven from the newest piece made into the previous one. The desired angles are created by sight only on the next piece to be attached. In other words the top edge of piece that it is attached to is usually always square.

I began with two center pieces that are as long as the center section of the plane, about four inches wide and edges parallel to each other. I then added a piece to the each end of the center pieces as long as the next sections forward and aft. Each of these second section pieces is made perhaps a half inch less wide on the end toward the nose or tail (So, four inches to match the center section piece and three and a half at the opposite end). This allows the plane to begin to get narrower top to bottom as it gets closer to the ends. These pieces were then beveled on the end that was to be attached to the center piece, making their opposite ends closer together when attached. This allows the plane to begin to get narrower side to side, as it goes to the nose and the tail. Finally, the tail and nose sections are begun by creating foundation pieces that are three and a half inches wide at one end and one inch wide for the nose and about three inches down to two and one half inches at the tail end. The ends of the tail pieces that attach to the second section are beveled so that they can be attached by nails but first very ends are beveled at an acute angle on the inside faces and brought together, similar to an axe edge. The nose ends are kept apart about two inches and the opposite ends beveled so they can be attached at their correct angle. Now, there is a completed frame that will act as the foundation for the rest of the fuselage.

Each piece added in the center section is beveled on the bottom, connecting edge (The top edges are left square). This allows the pieces to tip in toward each other in an arch to be connected with a final 'keystone' top and bottom to complete a rough, polygonal cylinder. The ends of the center section pieces are all square and ready for the second section pieces fore and aft to be beveled and attached. Each piece of the second sections is beveled on the connecting edge and the connecting end and the width narrows as it gets closer to the nose/tail. This creates a truncated, conical shape as the pieces come together one by one. Finally, the tail and nose pieces are beveled on a connecting edge and end and the width narrows to zero or in some cases an inch to half an inch. These become the final rough cone shapes of the tail and nose.

Each of the pieces is cut from a rough cut hardwood lumber called Wawa, by using a hand saw, either manual or electric. In the case of the manual saw, the tool is held vertical, above the board, with the teeth facing away from the cutter and in essence "pulled" down through the wood (the motion is like pulling a bell rope down). When I first did this I was very skeptical, but it took very little time for me to get comfortable and begin using this new technique. If the piece needs to be tapered (narrower at one end then the other) it is done now by sawing. When making the central foundation pieces each edge is hand planed flat and straight, but square is not paramount. The attaching end of the second section pieces and the nose and tail pieces are beveled using the hand plane before being nailed on. This is relatively easy because Wawa is reasonably soft and the wood is green. (Green means the moisture in the wood has not been dried out, either by letting the cut lumber sit covered and allowing the moisture to stabilize with the surrounding air or continue to force moisture out by slowly cooking the water out in a lumber kiln.) The moisture in the wood keeps the end grain wood fibers from bending or collapsing as the hand plane blade is pushed against the wood in an attempt to cut it. The only issue for me is keeping the hand plane straight as it moves over the end of board that can be as small as an inch wide.

Each new cut piece is ½ inch wider and an inch longer then what is needed to accommodate beveling and adjusting the fit of the piece. The newly cut piece is set on the top edge of the foundation frame where it is to be attached. The new piece is then tipped on the back corner of the edge toward the center to what is the presumed angle to start the cylinder. The gap between the top front corner of the edge of the foundation piece and the bottom front corner of the edge of the new piece is the amount to be taken off the back corner of the edge of the new piece. This is where you take the gap you see and transfer it to the back bottom edge of the board by holding a pencil point at the presumed distance from the edge and with the aid of one or two fingers on the edge move the pencil parallel to the edge along the length of the board. Now the board is placed in a vice and the hand plane is used at an angle to take shavings off the corner of the edge of the board until one side of the plane blade hits the pencil mark and the other side just barely touches the opposite corner of the edge creating the anticipated bevel. Take the board back to where it will be connected and see if the angle is correct. If not, redo until it is right. The more experience you have the greater the accuracy the first time. If the end of the new piece needs to be beveled it is done at this time as well. Sometimes the end has to be adjusted to accommodate the bevel of the edge and vice versa.
Once the piece fits and is at the correct angle it is nailed on using 6p box nails. Box nails are the only nails available, and box nails have large heads. The form building process includes forcing the heads of the nails below the surface of the wood with a punch so that the surface can be shaped and rounded. Sooo, each head of each nail has to be reduced by hitting the edge of the nail head with a hammer on an anvil. The 'anvils' are old, cast car or truck parts with various flat surfaces. These 'anvils' also serve as hold downs to keep boards steady while cutting with saws. When the nails are set into the green wood they begin to rust and grab the fibers around them and hold very fast. In fact the actual pounding of the nail bit by bit into the pushes the wood fibers out of the way but the fibers push back and grasp the nail after it has been fully set. Using nail guns to shoot nails saves time but the physics between the nail and wood is not the same. The force of the gun tends to make the nail rip the fibers and the grab is less strong.

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