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Building Kobuk
           As *** most any task that is undertaken alone, deciding to build the boat was the hardest part of the job.  Once committed to the project, each step towards its completion was a small nibble out of a big pie.  I knew it would take years to finish; I knew that no matter how generously I estimated the time it would take me, the actual project would take longer;  I knew that the cost would be more that I could afford.  All this I knew because it had been true when 25 years earlier I had built a small cruising sailboat in Hawaii.  That earlier success, though, had given me the greatest feeling of accomplishment in my life and remembrance of it was a constant source of encouragement as I started to construct Kobuk.
Setting up the Framing Box
Setting up the Framing Box
Making Frames
Making Frames
The Frames on their Stations
The Frames on Their Stations
            The first big problem was how to build a boat outside in a rigorous climate.  My home was located in the mountains of Utah at an elevation above 7,000’.  Summers there are dry and cool and ideal for outdoor work, but they are short—very, very short.  Winters, on the other hand, arrive early and leave late, and bring with them plenty of snow.  Since there was not enough room in the house to build the boat indoors, I had to create an outdoor area sufficiently protected that at least in spring and fall I would be able to carry on with the project. In the fall of 1997, I constructed a deck on the downhill side of the house that had sufficient space beneath to accommodate a 21’ boat.  The hull was to be constructed upside down on a perfectly level platform, so under the deck I set two posts in concrete and used them to fabricate a long, narrow platform that was to be the base for hull construction.  By the time that project was finished, winter was upon us and I was driven indoors.
Frames with Stringers
Running the Stringers
Bow Joinery
Joinery at the Bow
Planking the Hull
Planking the Hull
             It was possible, though, to work in the garage during the winter months, and so I set about constructing the frames that in the spring would be set up on the platform.  Over the next two years, the hull took shape—a structural ribcage of mahogany supporting a shell of marine plywood planking.  When all was shaped and fair, the entire external surface was sheathed in epoxy and fiberglass cloth.  When at last the hull was ready, the waterline was demarcated, a black bootstripe was painted on, four coats of white marine paint were applied to the sides of the hull, and two coats of red antifouling bottom paint were rolled onto the area below waterline.  On July 4th, 2000, friends were invited for an afternoon barbeque and everyone helped to lift the hull off its platform, turn it over, and reset it on a rebuilt support structure.
Planking the Bow
The Bow Configuration
The Hull Planked
Kobuk Planked
Spike on Hull Turning Day
Spike on Moving Day
            Traditional methods of boatbuilding often require levels of skill and experience possessed by few, but the hard-chined configuration of the River Rat and its simplified methods of construction outlined in the directions provided by Glen-L Marine made this building job the sort of thing that can be accomplished by anyone who is patient, thoughtful, and thorough.  Although the building process constantly requires mating wood surfaces that are something other than perpendicular to the run of the wood, one learns to adjust to this complication and after having had to cope with it a couple dozen times, the procedures involved  become quite routine.  The job was enormously simplified by the fact that the construction plans for the boat contained a 3’ x 8’ sheet of paper upon which every structural piece of wood in the entire hull is sketched.  All that needed to be done was transfer a pattern to an appropriate piece of wood and then saw it to shape.  Hull construction was neither simple nor quick, but anyone who can competently handle a tape measure, a hand saw, a screwdriver, and a plane can build this boat.  It is not the skill that is in question; it is the will.
Preparing Upright Rack
Rebuilding the Rack
Turning the Hull
Turning the Hull
Getting the Hull Turned
Turning the Hull
           For those of a technical bent, there are two aspects of the River Rat hull that might offer a little intrigue.  The first has to do with the planking of the bow area where the shape consists of more complex curves—curves like the surface of a sphere rather than a simple curve such as would exist on the surface of a tube.  Plywood planking can generally be flexed to fit a simple curve, as long as the arc is not too tight, but once a simple curve is present the plywood sheet is very resistant to flexing along a different axis.  Of course, the thinner the plywood the more likely it is that it can be gotten to cooperate.  The designer of the River Rat overcame the problem of curves in the bow by specifying that it be planked with two thin sheets of plywood instead of one thicker one.  This made it possible to fit the complex curves, but it had the additional benefit that when the second sheet gets glued onto the first it creates a remarkably strong form of planking.  If the two sheets together could be removed from the boat and inspected as an isolated item, its curves remain in the wood and their existence gives much greater rigidity and strength to the sheet of plywood than if it were flat.  This is especially valuable because the bow area of a hull is where the most ferocious aquatic forces are brought to bear.
Moving Hull Back onto Rack
Moving Kobuk Back onto the Rack
The Hull Turned Over
The Turning Job Completed
Framing the Deck
Framing the Deck
            The second aspect is similar in concept to the first.  As a hull is constructed, frames running from side to side and located at more or less equally spaced distances from each other give the hull its shape and insure that the sides and bottom do not flex inward to any significant degree.  The plywood skin for the hull is not laid directly on the frames.  Rather, stringers are run the length of the boat and perpendicular to the frames.  These stringers provide longitudinal rigidity and the plywood skin is attached directly to them.  In the bow area, these stringers must curve upward out of the water and to the deck level.  Since the bow is the area that needs the greatest strength, the River Rat designer specified that in this region some of the stringers should be two layers of long, somewhat narrow plywood that do not reach all the way to deck level and that get pulled back like the arm of a bow while the plywood planking is applied.  After the plywood skin is in place, glue is slathered onto those sprung tabs and they are released to press against the planking.  When the glue cures, these curved ply stringers give even more strength than usual to the forward area.  It is all very ingenious—lightweight and tough.
Holes Cut for Jet Unit
Holes Cut for the Jet Drive
Preparing the Bow Area
Preparing the Bow area
The Floor Stringers
Framing the Floor
           There is a tendency to think that once the hull is built and painted, and turned right side up, the job is nearly done.  Actually, you’re not even half way.  Most of the woodworking has been finished, although constructing the deck, fitting the carlings, building the cabin, installing the floor, fabricating the steering console, making the driver’s seat, assembling the engine box, and doing various other small carpentry jobs consumes more time than one might think.  The day finally arrives, however, when the boat looks finished even though intimidating tasks remain.  In this case, they were to install the jet drive, mount the engine, rig the steering and control system, run the wiring, and outfit the final product with a staggering array of storage places for particular items and pieces of equipment.
Floor Layout in Cabin
The Cabin Floor Layout
Starting the Cabin
Starting the Cabin
Cabin Framing
Framing the Cabin
            Of all the post-hull tasks, the one most stressful is that of cutting enormous holes in the bilge and the transom to accomodate the Kodiak three-stage jet drive.  I had gone out of my way to insure that the hull would be waterproof and in fact avoided as much as possible installing through-hull fittings (such as a self-bailing drain or thru-hull depth sensor) because I wanted to avoid potential leaks.  Now, however, it was necessary to do on a grand scale the very thing I had been trying not to do on a much smaller scale.  I must have measured the size and shape and positioning of the jet unit apertures at least a dozen times before actually starting to chop holes in Kobuk.  The caution paid off: the fit was perfect and after two years of operation Kobuk still still does not permit a drop of water to enter through the bottomsides.
The Cabin Planked
The Cabin Planked
David in the Cabin
David in the Cabin
Putting the Engine in
The Engine
            From the beginning, there was the question of what kind of engine to use to power the jet drive.  In the end--much to the disgust of my mechanic friend, Werner--I opted to install a gasoline engine rather than a diesel.  I became fascinated by a 240 horsepower rotary engine that is prepared for marine use by a company called Rotary Power Marine Corporation, located on Long Island.  The engine block is the standard 175 horsepower Mazda engine used in their automobiles, but RPMC modifies it for marine use and supercharges it.  Rotary engines are reknown for long life, low maintenance, and (less conclusively) fuel efficiency.  These were considerations, but the thing that sold the engine to me is its extraordinarily light weight.  At roughly half the weight of a comparably sized standard block engine, it frees up over three hundred pounds that could then be used to add all the things that would be needed for long distance cruising--a cabin, a bunk in the bow, an auxiliary outboard, a collapsible bicycle in a suitcase, an inflatable kayak, extra anchors, food supplies, and much more.  Even though it was not the engine he would have chosen, Werner was gracious enough to install it for me in his shop.  It took Werner a day to get the engine installed and attached to the jet drive--and this is the one construction job that I did not do alone.
Werner Installing the Engine
Werner Installing the Engine
The Steering Console
The Steering Console
Wiring
Wiring and Interior Work
             Building your own boat is not a rational thing to do.  The number of hours of labor required to complete the task are extraordinarily great and no matter how modest the nature of your regular employment you almost certainly would be better off economically to work at it extra hours and use the excess earnings to buy a boat.  In the case of Kobuk, I kept a log of the time I worked on construction and it tallied roughly 950 hours.  In fact, the time was much greater because I did not count such things as shopping trips--of which there were many dozens, each involving a 50-mile round-trip journey to Salt Lake City.   Neither did it count the hours of time spent studying plans and contemplating how an upcoming task might be done.  This thinking time almost certainly exceeded the time actually spent constructing.  If you were to spend this volume of time working on communicating with your spouse or significant other, the odds are that your relationship would be in really, really good shape.  Since I live alone, Kobuk absorbed virtually all of the thoughtfulness and intimacy that I might otherwise have lavished on some (undeserving?) woman.
Hinging the Cabin Top
Hinging the Cabin Top
Hinged Cabin Top
The Cabin Complete
The Finished Product
The Finished Product
             As one gets older, it becomes ever harder to remember things, and I found this to be rather shocking problem once Kobuk was finished.  Many of the small jobs that I did over the years are no longer clear in my mind and when I look at various aspects of the hull I wonder to myself how I managed to get them done.  It is very disturbing.  If the steering fails, for example, I cannot remember how I originally rigged it.  If the instrument panel with all of its wiring has to be removed in order to get at the bilge and repair a hole in the bottom, I cannot remember how--and in what order--its many wires and cables were attached.  If a fuel tank under the floor boards has to be worked on, I do not recall how I managed to run the half dozen fuel lines and electrical wires that are connected to it.  I dearly hope that these sorts of problems do not afflict me until enough of the voyage has been completed to compensate for the burden of having to give myself a refresher course on how I lived my life for five years.                
In Kobuk's Cabin
In Kobuk's Cabin
Kobuk on the Jordanelle
Kobuk on the Jordanelle
Kobuk on Powell
Kobuk on Lake Powell

HOME PAGE

Kobuk
The Voyage
Spike
Design
Construction

The Plan
The Log

Writing
Travel