Fairing the Canoe Hull

 

As the topsides curve becomes more vertical, the lower edge for each new plank needs to be tapered (to partial hull length) where it meets the previous plank.  At the sheer, the final plank will be full length.  The hull is rough now.  It will need to be sanded and filled when the planking is complete.  

Index of Entries, Jan. 2026

 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.

A Small Canoe                                11/25

First Signs of a New Build             11/25

Designing a New Hull Shape          9/25

What should I Build Next?              9/25

Planking the New Kayak                6/25

Putting the Pieces Together             3/25

New Kayak Design, Part 2              1/25

Creating a New Kayak                    12/24

A 'Leaner' Kayak                             12/24

 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

A Small Canoe, Fairing the hull

 With the essential frame completed, I decided to continue the canoe sequence in a new entry.  The next step will be to fair the hull in preparation for sheathing with narrow planks.  Most of the fairing will be easy; however, the stems will require drastic reduction from their present rectangular cross-section, instead tapering to a point at their outside edge.  I usually do that using an angle grinder with a coarse flap disk, checking frequently by laying a plank section along the ruling lines.  The designed slope from the major chine to the keel ends is X:Y:Z= 11/3.6/0.8, but practically, I will be using the adjacent frames as my guide. 

The chine stringer has been freshly bonded in place.  Four cockpit edging pieces are resting in place but will require trimming and will not be finally bonded until after other decking is completed.

Fairing Done!

For me fairing of this hull was a big deal.  Everything is bonded together; so, if I messed this up, I am in deep trouble trying to fix it.  Fairing includes not just beveling the frame edges to fit the curve of the hull but also reducing the 1 1/2-inch-thick blunt stems to sharp ends around a curve with changing bevel.  The keel edge needed a rabbet to receive the first plank; easy to do in the parallel mid-section, but difficult near the stems around a curve with a constantly changing bevel. 

Keel shown on left with future plank butted up against it.  A rabbet must be created to accept the plank in smooth transition and provide bonding surface.
 

I was able to bevel the stems at sheer level on my table saw before bonding them in place, but the curved section is still blunt, squared off.  This requires major reduction by hand to get the desired changing bevel.  First, I used an angle grinder with coarse flap disk, then a belt sander.

Th almost finished product of shaping the stem edge.  Any final adjustment will be done as I fit each plank.

A section of the keel rabbet, curved with a changing angle.  I couldn't think of a way use a fence, so it was done freehand, slowly and carefully with multiple passes, with a router and finished with a hand plane.

Major tools required:  Milwaukee angle grinder for the initial reduction of the stems.  Rigid router for creating a rabbeted landing on the keel edge after initial reduction with a power plane.  I could use a fence on the straight mid-section but had to freehand the router near the ends (carefully, a little at a time).  Craftsman router for finishing the stem bevels.  Stanley plane for finishing the keel edge.  No fancy equipment, but they get the job done.  (I forgot the power plane.)

With the routed edge to the keel, future initial planking will fit solidly and supported when it is time to bond it.  Now I need to create the planking.

I found a nice 1 1/2-inch-thick poplar board from which I have been able to slice many 0.20" thick planks.  The planks were first ripped on a table saw and then run through a planer for final uniformity. These planks are slightly thinner than what I usually use, but the frames here are slightly closer together (11-inch spacing) providing better backing.  Here you see the first full-length plank being trial clamped in place prior to epoxy bonding.

The last full-length planks are clamped into place.  A next full width plank would cross the major chine and, thus, would be part of a different projection at a steeper angle.  Alternately, I decided to use a one-inch-wide plank to complete this projection.  Because of the significantly steeper deadrise slope of the next plank, it will be only partial length. tapering at the ends and only about eight feet long.  Subsequent planks will also be partial length as the topside frame angle sequentially increases.  At the sheer, the final plank will again be full length for the hull.

First signs of a new build

 This week, I scarphed together two lengths of soft maple.  Why maple?  Because I can get it in approximately 8-foot lengths of 1/2" thickness by 8-9" width at an okay price.  It is a hard wood destined for a canoe-styled hull.  I used an 8/1 scarph ratio which is more than required.  The scarph was made initially with a hand power plane for gross reduction, then followed with a belt sander and medium grit.  The resulting surfaces were flat and mated well.  Epoxy adhesive was followed by clamps.  I have three hand belt sanders.  Why didn't we have them in junior high shop class!  Planes can produce 'chips'; belt sanders never do.

   With epoxy and paint, also kept indoors, weather will not be a factor for the maple in this hull. Once scarphed together, I ran the combined board through a thickness planer to bring the thickness down to a uniform 7/16" (0.435").  Why that thickness?  Because I wanted a balance of weight, strength, and flexibility for the slight rocker planned.  These were rough boards when received, thickness was not uniform, and they initially were not entirely straight.  I corrected the side curve with a hand plane and frequent checking with a straight edge.  The product now is straight, uniform, and has the flexibility desired while retaining sufficient strength.  This will be the plank keel creating a foundation, tying all the frames together. 

Today, I bought lumber for the frames: knotty alder.  Why knotty alder?  It is a beautiful hardwood, but relatively light, and at a reasonable price.  Of course, I hand selected the best boards and bought excess (perhaps enough for a next hull).  The drawback is the knots present but, for the frames, I will be bonding together rather short lengths of wood.  I think I can work around the knots. 

New lumber.  The keel is maple, overall length 136".  Current width is 8".  The other boards are 1/2-inch-thick knotty alder.  As you can see, the knots are not too distracting.  I can buy 1/2"x5 1/2" boards, which I can't produce on my home saws.  The frames will be 1/2-inch thick, and most will be 1 1/2" wide, but with 5 1/2" overall board widths, I will not be limited if I want a wider piece for a frame.

There will be twelve frames, symmetrically spaced fore and aft.  These are full-size rosin paper patterns.  At the turn of the bilge, I will need to use narrower strip planks to follow the increased curve.

I chose a 13-foot length with frames spaced 11 inches on center.  The length could easily be increased with 12 or 13-inch spacing.  Knotty alder wood was used, but I was able to avoid almost all of the knots.  Fifty-six total wood pieces were machined and bonded to make these frames.  I will need to notch these frames for the sheer and a chine.  

My next task will be to create the stems; they will add about 20 inches to the length seen here.  I will start with Douglas Fir 2x4" material to construct them.  The measured sheer piece when bonded will fix the frames at proper spacing.

The hull stems are now in place, ready to be bonded. Next the sheer will be better defined with a scarfed longitudinal.  I need to strengthen that area before I can turn the hull over for planking.  The half angle at the stems/ends is 18.12 degrees.  There will be small decks at the ends for which I need to add some support.

Many details were involved getting to this point.  That curved sheer strip is 157.7 inches long by calculation.  However, I didn't trust my calculations, so I made it a couple inches longer just in case I was wrong.  Then when fitting it, I wasted time recutting to the proper length of 157.7".  The intersection point with each frame was also precalculated.  Everything is held together with spring clamps currently.  A next step will be to mix epoxy and bond it all together.  At the ends where the sheer and stem and a short deck beam come together, the calculated intersections were perfect.  The task was to cut the actual wooden pieces to fit exactly with all the intersecting angles.  Hull length is currently 154 inches, but that is to the inside of the sheathing, when done it should be about 2 inches longer.

The curved laminated section of wood placed from deck beam to sheer illustrates where the edge of the small fore and aft decks will be when complete.  I plan to use a herringbone design of planks for decking.

I have doubled the sheer stringer and added another wood strip to define the major chine.  Next step will be to fair the hull in preparation for planking.  The lower portion of the stems currently have a rectangular cross-section and will undergo major reduction to a "V" cross section (like it appears at the sheer level).  Using a short straight section of planking, laid in the direction of the design mathematical projection, as a guide, I have found that an angle grinder with a coarse flap disc is best for achieving the needed reduction. 

The plank keel will also need to be routed to create a landing for the first plank, the garboard.  This will all wait until after the upcoming holidays.  

    

Designing a New Hull Shape

 The initial boat type, pictured in my mind, was of a slender canoe which could be paddled with a double-bladed paddle.  Speed was not a goal, reduced weight (partial deck) and slightly more forgiving stability were the goals.  The first thing was to picture the midships cross section; a bottom slightly wider and flatter.  I 'played with numbers' in an equation, used to define the major chine.  I could alter the coefficients of X, Y, Z in parabolic equations to get the right length (X), width (Y), and upsweep (Z) that I was seeking.

Next, I needed to decide the X:Y:Z ratio in the bottom projection; get the midships deadrise desired with progressively steeper deadrise approaching the stems.  In order to achieve this, the major chine needed to be reconsidered.  Position and spacing of frames needed to be included as well as width of the keel.  The Y:Z ratio is determined by the desired deadrise angle amidships.  The X:Y ratio is determined by the bow half angle of the major chine.  

Creating the topsides is perhaps most critical.  At this point, I had to start over with all new numbers for the equation for the major chine; however, there were multiple choices/combinations to pick from.  Incorporating three more projections to create a more rounded topsides shape, I discovered, would result in a hull that was wider than desired.  I used a paper sketch to help decide the coefficients for my topside projections.  I had to choose a major chine equation with less beam (Y).  Iterative process, but I was making progress.

When I started to achieve harmony between all the equations and coefficients, I had more aspects to consider.  Just how slender do I want this hull to be?  What should the overall length be?  What should the sheer look like?  How much depth amidships?   Height at the stems?  Should I consider creating a transom at one end; should the hull shape be symmetrical or should one end be slightly more tapered?  But those factors are not requirements- they are choices to create the specific boat you want.

With the offsets already generated, I needed to make two more projections: first to see a lateral view of the stems and secondly to see the shape of the plank keel.  All offsets need to be charted on paper before I can visualize the result.  (Hey, all I use is a TI pocket calculator: no computer screen.)

Full-size paper patterns for the frames, stems, and keel are complete, a little drafting practice.  Not sure they are interesting enough to post (pencil on rosin paper), but the cross-section shape is satisfyingly rounded.  I plan to add some partial decking at the ends.  The major dimensions will be 156" (13 feet) long, 30" wide, and 12" deep.

Thus far, my description has only been in generalities, should I post a table of numbers?  It will be some time before I can start building.  I do already have the plank keel lumber on hand.  Next task will be designing the frames and developing a list of materials.  

     

What should I build next?

 When we were out on a lake recently with our kayaks, I noted that rarely was speed the goal when paddling; we were just poking around in the channels of a flooded forest in a reservoir backwater, seeing ducks, geese, and even eagles.  And I thought, "I could build a boat for that type of outing."

I have started sketching out the dimensions for such a boat:  I imagined: a bit shorter, wider, and more open, less decking in order to reduce weight.  Right now, I am considering a hull 156" long and 30" wide, but I still have more numbers to calculate and sketches to create.  I envision it as a double-ended-paddle canoe, but right now I only have numbers to look at.   

I don't see any making any further modifications to my latest kayak design/build.  It fits our uses well, but the joy and challenge of building another boat is still calling.  This could be my next project.

Planking the new kayak

 Sorry for lack of progress, but we have been busy (mainly traveling) for the past three months.  Now I am getting back to planking the new kayak design.  Starting from the keel, the first projection is comparatively wide, Thus, I used 2" wide planks for that section.  As the cross-sectional shapes start to include more curvature, I will switch to narrower planks.  Using no fasteners, many clamps are required to hold each plank in place while the epoxy adhesive cures.

A straight, full-length plank is placed butted alongside the keel, and its position is marked on all frames.  At the ends of the hull, a short plank is placed by hand, marked by hand with pencil, then removed and tapered to fit the open triangle between keel and full-length first plank.  It takes a small plane and some trial fitting.  A much smaller scrap of planking is similarly marked and adjusted to fill the remaining small space.  These pieces were then immersed in a bathtub overnight before being clamped in place to dry.  This is an area of maximum curvature, the soaking makes them more pliable when clamping, requiring less force.

The first full-length plank has been placed port and starboard, and the second plank has been clamped in place for a trial fit.  The planks may look straight at first glance, but almost every plank has a slight curve which needs to be accommodated or removed using a small plane.  There will be one scarph joint per side.

These are full length, straight planks.  As you see, the planks are already reaching sheer height.  Following planks will be tapered and less than full hull length.  I do cleanup frequently, light sanding, knocking off resin blebs, vacuuming, so that I can make a better assessment of progress and note any flaws to be corrected.

Creating and fitting these tapered-less-than-full-length planks is exacting.  Each one requires a scarph joint.  Each plank about 11 feet long by 1 1/2 inches wide and with slight curvatures instead of being truly straight.  This is definitely not for the beginner boat builder or anyone with limited patience.  Then you must wrap each plank around the ever-changing frame curvatures and come out with consistent results.

Soon, the hull will be sheathed up to the sheer level, and I will post some new photographs.  Planking the deck should be much easier, but the inside of the hull needs to be finished prior to decking.

Before I start on the deck, I really need to finish the hull interior (while I have access), and perhaps I should finish the hull bottom.  The bottom sequence will be to sand any gross high points, do a penetrating coat of unfilled epoxy, then sand lightly, then a fill coat of epoxy slurry for any low points, and finally sand in preparation for primer and a final paint job.

  

The view is from the starboard side of the stern.  If you look closely, you can see that there are three partial length planks which taper to a point short of the stern (also short of the bow).  With somewhat straight planks and a changing bevel to the topside frames, this is what you get.  Some clamps are present because that final tapered plank has not been bonded yet and is held in place only by the clamps.

The hull has now been sanded with an orbital sander and 60-grit discs.  I am waiting on varnish ordered from Amazon.com; Colorado has no dedicated marine supply stores.  I need to varnish the hull interior before beginning the deck.  No new photos because the sanding does not alter the hull sufficiently for much of a visual difference. 

I now have three coats of varnish on the hull interior, and the first decking plank has been bonded, port and starboard.  "The decking planks should be a comparatively quick task.  It is just a matter of trimming the ends."  Fitting the cockpit edging will be slightly more difficult. 

Contrasting planks, light/dark, planks many of which are only resting in place.  Cockpit edging also passively placed.  As I work towards the centerline, access to the underside of the deck becomes very limited.

What I wrote above is wrong:  Fitting the deck planks is an exacting task.  Those planks, as initially cut, have variations (mainly curves) which need to be accommodated.  If you plane the planks until they are truly straight, they may end up being noticeably narrower.  The deck is highly visible, and the boards have to appear uniform and centered.  The centerline reference constantly needs to be rechecked.  I spent time planing boards to get what was needed.  Anything more than about 1/4-inch variation stands out.  Joints need to be tight, but not so tight that resin is excluded.  I can't have resin-filled gaps showing with exposed wood grain.

All those loose planks were trimmed, epoxy was applied, and they were all set in place in one session.  I used bricks for weight to hold the planks in place.  What you see here is after further trimming and sanding.  Using bricks seemed like a risky method, but the result looks good.

The deck does not look as good as it should.... my fault.  I used too coarse sandpaper and did some cross-grain sanding which left scratches in the wood.  The first coat of varnish really made those scratches stand out.  I was too impatient.

I probably have 2-3 more coats of varnish to apply.  Then, I turn the hull over and start painting.  The blue stripe is painters' tape.  Should I paint the hull blue/gray with a white stripe (where the tape is), or reverse it? These are the colors I have on hand.  The completed hull weighs 46 pounds; not light, but it is size, not weight, that makes it awkward to handle.  The frame with keel, prior to planking, weighed 17 pounds.  I think that I prefer a more rugged hull rather than a lighter but more delicate hull.
  

Having all the right tools is such a blessing.  When on active military duty (moving often)), I had a very limited tool set.  Now I have a well-equipped shop; no fancy tools, but a variety of modest tools that can get the job done.    

 

Final finish, and I am happy with it.  In places, I was impatient, and the finish could have been better, but the design looks good.  Visitors have said, "Why don't you build these to sell?"  I expect that I will be selling the oldest one, but only to make space for new projects.  We are going to be busy traveling for much of the next year, so I can't put a time schedule on a future boat project.

We took my two completed kayaks out to a local lake recently, along with another couple who brought their own plastic kayaks.  There were wind and active powerboats (wakes) on the lake, and these kayaks handled everything okay.      

At this point, I am pleased with all the dimensions/ proportions chosen for this project. I am wondering if my use of a slightly wider keel plank will noticeably increase hull stability.