Recent Events of the MTBE
It has been a busy summer, so far, at the MTBE Boat Works. The Mt. Baldy Expedition is very happy to announce the Boutez en Avant is off its strongback and has been turned over. We now have an expeditionary sailing dinghy that will float (please see photo at right). We have also ordered the Boutez en Avant’s sails from Torresen Marine, Inc. in Muskegon, Michigan. They should arrive any day now.
Milling the Chine Logs
After successfully attaching the transoms, it was time to build the Boutez en Avant's chine logs. The chine logs are two 14' stringers that run along the hard angle, or chine, where the bottom planking joins the side planking. They are made of long pieces of Douglas-fir cut at a 123 1/2 degree angle forming a parallelogram, 1 1/8" x 2 3/8". These are then bent over the strongback and connected to the bow and stern transoms with the transom gusset plates. The chine logs create the large, long-grained surface area needed to make a joint strong enough to hold the planking together.
Although Captain Short recommends getting the chines milled to size at the lumberyard, we felt we could do it ourselves at less cost. This decision led to more problems than we had anticipated. We needed to mill the chine logs from a plank measuring 2" x 6" x 14’. During the spring thaw, our lumber absorbed a great deal of moisture. The combination of this moisture, some funny grain, and the large size of the pieces being worked left us unable to cut them precisely with our power tools. The tools were at their maximum capacity, and the shop was too cramped. The blades kept sticking and burning in the moist wood making for a dangerous situation and resulting in unusable, jagged pieces of wood.
After the third or fourth attempt, it seemed best to cut them down by hand using a Japanese handsaw and some shims to keep the blade from getting pinched (near right, click to enlarge to see the jagged cuts left by the circular saw). It took time and a lot of physical energy, but it worked (far right).
Once the lumber was cut to size, it was time to bevel it at the 123 1/2 degrees. We ran one side through our benchtop table saw (which Jim affectionately calls the “little saw that could”) and beveled the other side by hand to insure a safe cut with such an oddly shaped long piece of wood (far left). Ultimately it took six days in the shop, but we had finally completed the simple operation of milling the chine logs to size (near left, click to enlarge and see the parallelogram's angle).
Steam-Bending and Installing the Chine Logs
The chine logs were far too thick to simply bend into the arc created by the joint of the Boutez en Avant's side and bottom planking. We solved this common wooden boat building problem by steam-bending the chine logs. Steaming wood quickly raises its temperature and moisture content allowing it to be bent easily without breaking. Every boat builder's steamer is different, as they are usually built from whatever materials are at hand. We built ours from plywood salvaged from old gallery walls and designed it specifically to fit our 14' chine logs. It consists of two 8’ long crates held together with a wooden collar. A venting tube connects them to a boiler made from a five gallon gas can that is heated by a high-BTU burner, or Cajun cooker (below left).
Hui-min prepared the gas can by cutting the top off and widening the rim with a hammer and anvil, so the can wouldn't blow up under the pressure of the boiling water (top center). We then made a plywood adaptor to attach the mouth to the venting tube (top right), and it was ready to go.
The steamer worked like a dream. Our burner can boil 2 1/2 gallons of water in under twenty minutes, and our steaming box was ready to go in half an hour (above left). We popped the chine logs in the door at one end and let them steam for an hour (above right). When we pulled them out, they were so hot we needed gloves to handle them.
The damp chines logs bent easily into position over the strongback and we quickly clamped them on tight and let them cool in the shape of the arc (near right). At right, you can see the port and starboard chine logs sitting on our table ready to be installed.
The Transom Gusset Plates
Before we could finish installing the chine logs, we had to make the transom gusset plates, small brackets that strengthen the joints between chine log and transom. The gusset plates were cut from two pieces of 1/2" Meranti plywood that were clamped to our make shift vice on the work bench (far left top) and beveled together to the precise angle the chine logs would enter the gusset plate ( far left bottom). The gussets were then screwed and glued to the transoms and the chine logs attached to them (above).
Side and Bottom Planking
The Boutez en Avant’s side and bottom planking are both made from 3/8" Meranti plywood. The side planking is approximately 2'x14’, and the bottom planking's twice as wide at 4'x12’. Since our plywood comes in standard 4'x8' sheets, we extended our planking with a scarf joint following the same steps we did with the keelson (see Issue 3). For the port and starboard side planking, we beveled four sheets of plywood at a 1:8 ratio to maximize the adherable surface area and wetted them out with the first coat of epoxy (below left).
The entire time we were gluing up the keelson we were struggling against cold temperatures and slow set times. The planking was another matter. With shop temperatures seventy degrees higher, the glue was absorbed into the wood at a much higher rate, and we had to cut out the glue starved joints (above middle) and re-scarf them. Jim stacked the sheets four on top of each other and re-planed them all at once (above right) making re-scarfing them much quicker.
Once the side planking was scarfed to its 14' length, Jim, Hui-min and Andrew all came down to install it. It was an exciting day all around. We would finally see the Boutez en Avant take her form. For Hui-min, it also marked her first day back after an absence of several months due to an injury (seen with the boat at right on her first day back).
We clamped the 2'x14' planking to the chine logs and transoms and marked off their outline on the planking. We then removed it and cut it to size with a jigsaw. After covering the clamps with tape to protect them from glue, we hurried to glue and screw the planking onto the chine logs and transoms before the epoxy started to set up in the heat. After what seemed like an endurance race between the glue-up time, the heat, and the lubricating wax melting all over the silicon-bronze screws, the planking was installed and the glue joints were cleaned.
Jim cutting the planking out with the jigsaw (above left), a detail of the a taped up clamp (top row middle), Hui-min and Andrew screwing down the port side planking (top row right), Jim under the boat scraping out epoxy drips (lower row left), and the Boutez en Avant with side planking (lower row right)
The bottom planking was similar to install, but we were dealing with a much larger surface area to glue up and a tighter curve to bend the planking to. Jim, Hui-min and our newest shop assistant, Bill, marked off the planking and cut it to size and then raced to glue it to the chine logs, transoms and keelson climbing all over the bottom of the boat and using body weight to keep the planking in position. This time we could not use traditional wood clamps to hold the planking down, so instead, we used a series of Spanish wind-lasses, a simple method of twisting the rope around a stick to cinch it tight.
Jim holding the planking down while Bill traces the outline (above left), the bottom planking with its long, 4' scarf ready to install on the boat (top middle), Jim and Hui-min on top of the boat screwing the bottom planking to the keelson (top right), the spanish windlasses in action (bottom middle), and planing the extra plywood off the sides (bottom right)
The Turning of the Boutez en Avant
Once the glue had set up it was time to turn our dinghy over. We were finally taking her off the strongback and could start working on the inside of the boat. Jim, Hui-min, Glen and Chresten all showed up to carefully lift her off the strongback and turn her over (right). It came off without a hitch.
The MTBE is now a member of both the Smithsonian Institute and the National Geographic Society. The MTBE is also pleased to announce our newest shop assistant, Bill Berger. Bill is an experienced fabricator of guardrail banisters and recreational decking.
We would like to make a correction to Issue 3. The church stone behind the shop is not from the New Salem First Evangelical Church but from the Salem Church of the Evangelical Association. We apologize for the mistake.
The Mt. Baldy Expedition is partially supported by a community Arts Assistance Program grant from the City of Chicago Department of Cultural Affairs and the Illinois Arts Council, a state agency.
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