Monday, August 26, 2024

Index of Blog Entries

Find a topic of interest in the lefthand column and note the associated date (month/year), then click on the associated year in the righthand column, and you should find your chosen entry nearby.

 Boating is more Satisfying....          8/24

What is Next?                                   6/24

Careers and a Hobby                        6/24

A Smaller Kayak                              12/23

Finishing the Planked Hull                7/23

Rules for Developable Hull surfaces 6/23

Finalized kayak Design                      1/23

Starting a New Design: Kayak           1/23

Now I Have a Boat to Look at            8/22

Next Step in Design Evolution          11/21

A Real Sharpie                                    3/21

Another Guide Boat                            2/21

Finishing the Guide Boat                    12/20

Finishing the Planking                        5/20

Creating a Developable Surface         5/20

Solving the Hull Sheathing Conform. 4/20

Planking the Guide Boat                     9/19

Garboard Sheathing                            7/19

Viking Ship Museum, Hull Fairing     6/19

Defining the Shape                              3/19

Creating a Boat 'Skeleton'                    3/19

Starting to Cut Wood                            2/19

First Steps for the New Design            12/18

The Improved Guide Boat                   10/18

Getting Ready to Build                         7/17

Completed New Model                         9/16

New Design Model, Part II                   8/16

Creating a Model for a New Design     8/16

Beautiful Boats of Scandinavia             7/16

Vietnam Memories                                10/15

Along the Adriatic Coast                       10/15

Grand Tetons N.P. Boating                     8/15

Modified 'Next Boat' Design                  4/15

Sail Design                                              2/15

Next Boat?                                              12/14

A Day at the Lake                                    9/14

Resting on its Design Waterline              7/14

At Flaming Gorge, Utah                          7/14

What a Day!                                             5/14

The New Boat Looks Complete               3/14

Why I use Rosin Paper                             3/14

The Boat Windshield                                2/14

Winter Progress                                         2/14

A Voyage to Remember                             11/13

Instrument Panel                                        11/13

Now for the Accessories                            10/13

Sample Developable Design Calculation   7/13

To the Deck and Onward                            7/13

Slow but Steady Progress                           5/13

Finally, the Hull is Turned Over                 1/13

Hull Sheathing                                            7/12

The Origin of Boat Bowls                           4/12

Another Year, Another Boat                        4/12

First Season Report                                     9/11

A Trial Run                                                  6/11

Finally in the Water!                                    5/11

Out of the Shop                                            12/10

Ready to Leave the Shop                             10/10

Finishing the Stern, Onto the Windshield     7/10

Wood Decking                                               7/10

Interior Details                                               6/10

Finally, the Hull is Upright                            4/10

Planking the Hull                                          11/09

Initial Hull Sheathing                                      8/09

The Design Becomes a Reality                       5/09        

Hull Design Using Simple Mathematics       12/08

Design Evolution                                             7/07

New Direction                                                 7/07

Model Lobster Boat                                       11/06

Updated Drawings                                           9/06

Maiden Voyage                                                5/06

A Semi-planing Powerboat                              5/06

Guide Boat Pictures                                         5/06

Adirondack Guide Boat Concept                     5/06

A Real Disappointment                                    5/06

Panama Skiff                                                    5/06

Kayoe or Canak?                                              5/06

Where did this Unusual Interest Originate?     5/06

     

         


Sunday, August 25, 2024

Boating is more Satisfying when the Boat is your own Design

 


I designed and built this 18.5-foot-long runabout which was completed in 2014.  Size-wise, it has ample space for up to six people.  The 75 HP engine is good for about 35 MPH, although altitude, load, prop pitch, and even wind resistance can be factors.  Someday, I would like to run it at low altitude to see how much more speed might be attained.  It is light and easy to tow, due to the wood/epoxy construction, which is important because here in Colorado there are very few nearby lakes.  We have towed it as far away as Coeur d' Alene, Idaho.   Being light also means that it takes less horsepower to move it through the water, and it is very fuel efficient.  The only drawback to being light is that when maneuvering for retrieval to its trailer on a windy day, wind can push it off course when at idling speed.

Behind my runabout in the above photo, "Mountain Dancer", the larger green and white boat is my brother's 27-foot Sea Ray cruiser.  It is ocean-capable and has twin engines totaling about 450 HP.  

This past weekend, we ran the boat on Ruedi Reservoir (7,800' elevation), near Aspen, Colorado.  The weather was perfect except for an uptick in wind speed during retrieval of the boat.  The weather this past weekend was unpredictable with quick shifts between sun and clouds or rain.  Fortunately, everyone did their part to properly position the boat and trailer.  The dock at Ruedi is pathetically small which didn't allow much space for handling of the docking lines.

A few years ago, when my brother, Jay, and I both had our boats on Jackson Lake, Grand Teton, NP, his wife, Connie, made a short video of my runabout on the lake.  The scenery there is spectacular, and you can see the runabout moving smoothly across the lake's surface.  If we are lucky, you may be able to view this video on YouTube at the following address:

 https://youtu.be/X1m7WiJS7S8


                  
We have the full canvas enclosure for our runabout in case of bad weather or the rare choice to sleep aboard.

Saturday, June 15, 2024

What is Next?

 I sold two rowboats boats this week, helping to clear out the shop.  I have one more that I want to sell. (Now sold to a gentleman in California; he drove here to get it.)  If you have been following my blog, you can see that as I build a design, I am always asking "What could I do better?"  Then the next build incorporates those changes.  The boats I am letting go are perfectly adequate but have been replaced with slight improvements, sometimes with only aesthetic differences.  And I am at a point where few new improvements come to mind on my rowboats.  A sailboat would be a different project, but the Colorado mountains might not be a good place for consistent winds and sailing.  

I have been looking for the proper trailer for transport.  I finally located one, but it needs work (23 years old) and modification; it had been set up for hauling bicycles.  I bought it; used boat-type trailers are hard to find in Colorado.  I have replaced the tires, inner tubes, bearings, and axles.  I exchanged its setup for bicycles with a 5 1/2' by 5 1/2' deck for small boats.  Next project:  I have discovered that not all the trailer lights work.  The wiring is old (obviously) and not well protected.

I need to get out on a lake with my newest boats; that use may suggest further improvements.  The boating season at the altitudes where we live, 7000+ feet, is only about six months long, making for a limited opportunity on our lakes. 


The blue/gray kayak was my first recent design attempt.  The natural finish on the second kayak is a design for my wife.  I already have ideas for an improved design to slightly reduce width and weight.

 

This trailer came with a short tongue and a long tongue.  I attach the short tongue for use while in the shop.  The trailer (a commercial build from California) has coil spring suspension and motorcycle-type tires.  New tires are not easily found, but I was able to get some off Ebay.com.

I had a contractor come by to look at some home repairs.  When he spotted my boats, that is what he wanted to talk about.  He told me to call him when I get ready to sell the next one.  My most recent sale was for $400.  The gentleman from California told me I am underpricing my boats.  1) Colorado is a boating desert.  There are few buyers here.  2)  Mostly, I care for an appreciative home for these boats.  Each one is a unique design and product.

UPDATE: With everything completed, we got out on a local reservoir today, and I learned some lessons about kayaks compared to guide boats.  My guide boats have a steeper deadrise but are more stable, not just due to the slightly wider waterline beam but also due to having two oars in the water instead of one paddle blade.  Two oars also make for quicker turns, but the kayaks had good directional tracking when paddling.



While we were out on the lake, the wind increased in gusts, and I gained appreciation for the influence of increased freeboard.  As the wind became stronger, it shifted, and we realized that we would be paddling to windward to get back to the launch area.  Those of you familiar with kayak design can laugh and shake your head at this amateur making mistakes instead of using a proven design.  For me, it is just another project which I can fix.    


  

Sunday, June 09, 2024

Careers and a Hobby

 

My interest in boats, shared with my brother, started when our uncle gave us a decrepit plywood pram.  It was poorly cared for and leaked.  We sealed the seams with roofing tar and painted it with house paint.  Then we named it “Tar Baby” in honor of the tarred seams.  Later, our family bought a boat for waterskiing, a sport we learned to love.  Next, my brother and I each joined the US Navy Reserves when we reached 17 y. o. and while still in high school.

My Navy service included crossing the Pacific Ocean twice (LST hull, then destroyer), spending most of a year in the Mekong Delta, next providing coastal fire support, and finally cruising north from Vietnam to Japan for ship maintenance.  My nautical education began with navigation school in San Diego and subsequently continued with real life experience and onboard texts as my guide.

One early morning, while on a training exercise off the coast of Mexico, I witnessed a rare event of the sun’s rays being bent, diffracted, by the earth’s atmosphere just before sunrise so that, for a few moments, I was able to see islands that were far beyond the visible horizon, more than a hundred miles away.  While crossing the Pacific, we went through the edges of a typhoon, experiencing huge waves crashing over the bow, waves sweeping across the deck, and the entire ship shuttering as the plunging hull intermittently exposed the propulsion screws from the seas.  From instances like this, I developed respect for the unflagging nature of the ocean’s power and its vastness.

After my release from the Navy, I went back to my mechanical engineering studies at the University of California, Santa Barbara.  The Pacific Ocean forms one boundary of the campus.  The school has a crew club (rowing), surfing team, and a fleet of sailboats at Santa Barbara harbor.  Taking a sailing class out of Santa Barbara, I was intrigued by the forces in play determining sailboat performance.  At the same time, I needed a senior research paper topic for my engineering studies.  Thus, I chose sailing hull design as the topic of my research paper.

I was able to design a system for testing scaled hull models in a calm swimming pool with valid and consistent results.  The drawback was that I needed to construct a series of hulls with varying parameters to test the influence of design changes and be able to describe them mathematically.  Simple photos would not suffice.  Researching previous hull design information, sparse in the published literature, I was able to customize mathematical equations and methods of projection to describe a limited range of hull forms.

My research paper was successful.  But my search for fulfilling employment as an engineer was not so successful.  Much of my duties consisted of reviewing architectural plans and financial data, looking for mistakes and ways to increase efficiency.  Our engineering department was blamed for project cost overruns; in response, I did a comprehensive review of the past ten-years construction bids (for projects to be built several years later) showing that, in fact, it was the marketing department failing to allow for inflation that resulted in the cost over-runs.  The big boss was a marketing guy and did not want to accept my facts.  I was disgusted and started looking for alternatives to these petty office politics. 

I considered a degree in naval architecture, but, at a visit to UC Berkeley, was told that ship design had no future in the US.  Designing ventilation, plumbing, and electrical systems for ships would be a better pursuit.  I considered sailing around the world (even to the extent of buying an ocean-going sailboat), but after reflection, realized that was just escapism, avoiding difficult career choices.  My degree would be obsolete by the time I returned from such a voyage.

I considered medical school, but a suggestion from my wife, Dawn, changed my career path to dentistry, a whole new environment.  My focus became people: biology, chemistry, physiology, and psychology.  In our classes, little was said about the molecular structure of the materials we used, that was for engineers to know.  Our dental text included a chapter with sections written by one of my UCSB engineering professors, but it was given little attention.

Was my engineering background to be forgotten?

I really enjoyed my career in military dentistry, not completely retiring until age 75.  There were many patients I could list where I was able to not just ensure healthy teeth but improve their lives.  That was always my goal.  Let me give one example: a woman (wife of a soldier) came to our office in the Netherlands in pain with her face swollen due to a tooth which had rotted off into her jawbone (no visible tooth).  It was a surgical extraction with ample drainage of pus, but I was able to treat her comfortably with adequate anesthesia.  After she departed, I told the receptionist, “I want to see the mouth that kisses her mouth.” (her husband).

Because her husband was a member of the US military, I was able to order him to come in for an examination.  Sure enough, he had significant dental problems also.  Neglecting your dental health can be grounds for separation from the military.  We treated both parents empathetically, comfortably, and were able to bring them into healthy, confident smiles.  Not just treatment, but education and motivation.  Then, they voluntarily brought their children in, and we were able to correct all developing problems.  We replaced fear, ignorance, neglect and shame with dental health and a confident future.  What better professional reward could I have?  This sequence was repeated with many other patients.  Being in the military, cost (other than not wasting taxpayer money) was not a factor.

Can I tell one more story concerning the base commander’s wife in Germany who was a dental phobic?  I diagnosed a dental problem of hers before even seeing or talking to her (but I had treated her husband who brought her previous radiographs to me).  His wife was talking to my wife by telephone when she mentioned that she had a minor toothache.  My wife whispered her comment to me.  I told my wife to ask her if the discomfort was on the lower right toward the back of her mouth.  She replied to my wife, "How can he know that!"  I had carefully reviewed all her previous radiographs before filing them and had noted a developing defect in that lower right area.  After her toothache was comfortably treated, she came in for a series of cosmetic dentistry appointments, completely overcoming her phobia.  How about another…. enough said.  I could go on and on.  Dentists tend to get little respect, but on multiple occasions I have witnessed the dramatic improvement in a person's entire outlook from a healthy, pleasing smile.  That is all the satisfaction I need.  

Was my engineering background to be forgotten?  No.  I went back to my senior engineering research on hull design using mathematical concepts.  Over the years, I have built 13 boats using my mathematical design approach and expanding on it.  While in dental school in Omaha, I built a canoe for the small nearby lakes and rivers.  While in Panama, I built a cartoppable sailboat for the beaches, and shallow reefs there.  While in Alabama, I built a twenty-foot, two-masted sharpie sailboat for the large reservoirs there.  During a ten-year period (residency, Board exams, clinic management) I was too busy for such projects.  Part-time work and then retirement have given me more time and a better workshop for my design ideas including two outboard runabouts.

I have enjoyed all of it: studying navigation, engineering, dentistry, woodworking.  My father taught me by example that being a professional does not require a college degree; it is your attitude toward the task at hand that will make you a professional.

Life is a process of learning and becoming; dreams evolve to plans, then to realization, while facing the challenges of new situations along the way.  We learn, grow, and find meaning as we explore the world around us.

Sunday, December 03, 2023

New project: a smaller kayak

 Having just completed a large kayak with ample storage space, it weighed in at sixty pounds, which is too much for my wife.  But the basic design looks good, now I plan to create a slightly smaller version of the same exact design.  Frames will be spaced at 13.5" instead of 15" and the depth is reduced by 2.5".  I wonder how different the hull will be visually.  Progress will be slow because of the holidays, tax prep, and a long-planned trip.  Design dimensions are 153" by 26.6".



 A hint of what is to come:  The deck beams are laminated.  They all have the same curvature; thus, they could all be built on the same form.  The remaining parts of the frames are built from individual pieces that are half-lapped and then bonded together.  The plank that all the frames are resting on will be the future keel.  That keel will have a slight rocker by design.  My strongback, such as it is, consists of a ten-foot long 2X6 resting on two sawhorses.


Kayak frame completed.  After I have the bottom and topsides planked, then I will alter the deck beams to create a cockpit.

1) The offsets for all frames were mathematically calculated.  The shape of the plank keel and the bow entry & stern were also calculated.  The total length of the sheer and length at each frame connection, also calculated mathematically.  

2) Full size drawings of frames, bow & stern, and keel ends were drawn.  Most data points are only a few inches apart.

3)  Individual pieces were constructed from those drawings.  Midlines were marked on each frame for visual reference during assembly.

4)  Given that three points define a plane, each frame can only fit in one position defined by the keel and port & starboard sheer connections.  At bow and stern, additional rigid triangles are created by the bow, keel, and port & starboard sheer connections at the adjacent frames. This forces the port & starboard sheers to meet in a predetermined fixed relation.

5)  With epoxy and plenty of clamps, all connections only fit in one position, allowing assembly without use of a strongback form.  Planking can now proceed on this rigid underlying total frame.


Now I have started planking the hull.  With natural wood, each plank has to be considered individually.  Few are absolutely straight.  None are the 14+ feet long needed; thus, each requires a scarf joint.  I ran them all through a planer to get uniform thickness.  The initial planks all are positioned in the 1st projection of the hull form, meaning they all lie in one plane and can be laid straight without any taper.

But this is a triple chine hull (four projections); at the turn of the bilge, angles change several times, and intersection of planes required that planks located at the turn of the bilge be tapered and less than full length.  The taper was determined by clamping the future plank in place and then tracing the overlap from the inside of the hull as a guide for trimming.

No fasteners used; tomorrow I will bond this partial length plank in place with epoxy and plenty of clamps.  Instead of spiling, I clamped the proposed new 1.5" wide plank in place and then traced (inside the hull) with a pencil the overlap between the new plank and previous plank. This guidance was then used to trim the new plank to its tapered form.    

No strongback or forms used.  The plank keel, frames, and stems create a solid skeleton to build on.

Planking of the hull is complete except for finishing.  Next, I will concentrate on cleaning up the interior and finishing it.  Other tasks to consider are the sanding and filling of the hull exterior and planning the cockpit and decking.  Still, this is a nice milestone of completion where it really looks like a boat.

Three coats of varnish on the interior.  The exterior has been sand/fill/sand with a flowable epoxy paste. Now I am creating a contrasting pattern of decking planks.  The color difference will be enhanced when I start varnishing.  The darker planks are select alder wood.  Alder is normally known for its knots; this is select alder; no knots, but still there are variations in the grain structure which cause slight curves in these planks.  In a ten-foot plank, you may find 2-3 slight curves.

When you are laying multiple adjacent planks, you can't allow gaps due to this waviness.  Thus, each plank needs to be fitted to its position, slowing the process.

Finished planking the deck and fitting the cockpit edging.  Now it will be more filling any flaws and more sanding of the deck.  Then paint and varnish.

Paint and varnish added.  I am using all Epifanes products and am pleased with the results.  The seat is being varnished separately.  Now I need to get a light trailer to carry either two kayaks or a single rowboat.  Colorado has few lakes, and many are at altitude where they are covered by ice for almost half the year.  Most marine products I use need to be mail ordered.  But the low humidity is excellent for boat building.


Saturday, July 22, 2023

Finishing the planked hull

 Now that I have a fully planked hull to look at, I am asking myself, "Is this a kayak or a canoe?  Dimensions are 27" by 170".  I wanted to make a somewhat wide and stable hull for my wife, but I think it has more freeboard than needed, which gives it a canoe look.  Whatever.  I have already bought the keel plank for a next build.

I will be turning the hull over for sanding, fill coating, and more sanding to get a smooth exterior.  Looking at the hull, it would be very difficult to realize that this is a developable surface hull.  Completely designed using the mathematical accuracy of developable projection; no strongback required, in the final step, instead of connecting all offsets on the hull frames with straight lines, they were connected using a smooth curve.  By sheathing that curve with narrow planks (1.5" wide), the result is a curvaceous hull.

Next comes the sanding: Random orbital with 80 grit discs.  My Porter-Cable sander is falling apart; time to replace it.

My goal is not to sand it completely smooth.  I want people to see that it is a wooden planked hull.  What you see here are spots where squeezed-out resin was wiped off the hull surface.

When planking the hull, I put a bead of epoxy paste on the edge of each preceding plank before adding the next plank.  That requires cleanup of the squeezed-out resin, but better that than a dry joint. When planking was complete, I used a disposable brush and un-thickened resin to fill any remaining small voids.  I then used a flowable resin mixture, thickened with WEST 407 fairing filler, and wiped the entire hull using a flexible plastic squeegee.

That was followed by progressive sanding: 60 grit, 80 grit, and 120 grit (by hand).  This wasn't as onerous as it seems, using my new DeWalt random orbital sander.  Repeated vacuuming and next I will wipe down the hull surface before putting on a coat of primer.


Changed my mind.  I was anxious to take on the deck sheathing.  First, I cleaned up resin blebs in the interior and put down three coats of Cetol plus a high gloss sealer coat on the interior.  Now, I am applying deck planks two at a time, port and starboard working toward the centerline.  I will be adding hull access ports fore and aft as the planking proceeds.

Then it will be time for a vacation break. 


We are looking at the hull from the stern.  The hull is not symmetrical fore and aft; the bow is actually slenderer than the stern.  With the plumb ends, the waterline is almost 14 feet long.  Next, I will create flush hatch covers for the fore and aft access openings.  Then install a raised edge on the cockpit and build a seat for the paddler.

Those lifting handles are just resting in place; I need to do a lot of finishing on them.  The deck has only had a rough sanding and will require further fill and smoothing.

Hatch covers and cockpit edging in place.  This is a stern view; my camera makes it look like this would be the more pointed bow, but that is just wide-angle distortion.  I love the flush hatches; am trying to decide what type of latching system to use without visual impairment.

Now, all I have to do is make a seat for the cockpit.  Done! (but not shown)


Next up:  Using the same design numbers, I am creating a smaller version of this hull: 10% shorter and 2.5 inches lower.  Progress will be slow due to the holidays and a planned trip.