EasyB - a Solo Canoe  
by Skip Johnson - Houston, Texas - USA

NOTE: EasyB plans have been updated as of Jan 2011 - click HERE to download the latest version.

Introduction

Every time I paddle away from shore in EasyB after spending time in other boats, mine or others, I’m amazed again at how easy she moves up to cruising speed. Chuck had expressed an interest in publishing the plans as a freebie but I declined since the essence of a computer designed boat is in the full size frame patterns and I wasn’t ready to supply paper for nothing. Fast forward a few years and Adobe’s pdf format has improved printing capabilities and my ability to present designs in pdf format has improved also.

So here is the current iteration of EasyB including full size patterns requiring a smidgen of cut and paste if you can print tabloid size, a bit more at letter size. The only change from the prototype was to respace the stations to 8” and redo the stem profile (again, several times, it is a hard curve to get right).

Plans are presented as is, there are a lot of good resources regarding stripper canoe construction and it seems most people will follow their personal preferences in any case. Anyone building EasyB for sale might keep in mind there is a large dose of good karma in compensating the designer for his efforts and some risk at the other end of the spectrum.

As always I’d be interested in discussing custom designs/commissions for those interested in such.

EasyB Design Brief

After several years there’s nothing I’d change in the overall shape of the boat, except the stem profile. The following is taken from the original brief with comments on construction changed in tense.

The boat’s shape is derived mathematically with parabolic curves for plan and profile with superelliptical cross sections, which guarantees a perfectly fair shape capable of being manipulated over a wide range. So our boat is 11’-8” L.O.A. 28” maximum beam, a bit asymmetric, the midsection 8” back from the midpoint. The sheer forward is fairly pronounced both for appearance and to make stripping easier at the chin of the bow. Just a little rocker, don’t need a lot of maneuverability in such a short boat and less rocker also keeps the prismatic coefficient up a bit, also a good thing in a short boat. Since an absolutely straight keel line offends my sensibilities somehow an inch or so will do. At the 4” waterline, our little boat will displace 4 plus cubic feet of fresh water or 255 pounds with a prismatic coefficient of 0.56 dragging 18.5 plus square feet of wetted surface through the water. It will take about 82 pounds to sink the boat an inch lower in the water, which should be about as much as you’d ever want to load the boat. Take 80 pounds out of the 255 leaves 175 pounds and you’ll be able to float in 3” of water.

Take all this stuff with a small grain of salt, freshwater or not. In the real world of wind, waves, current and all sorts of macrocosmic chaos I don’t begin to understand, A boat is a living dynamic thing, constantly changing and adapting to the conditions of the moment. We should all do so well.

Construction is conventional wood stripper, ¼” nominal wood strips with a layer of glass/epoxy both sides, 5-oz in this case. Actually 3/16” thick strips would work fine for a boat this size, but I’ve got a lot of ¼” thick strips already on hand and have neither the equipment nor inclination to take 1/32” off each side. Going to 3/16” thick strips would save some weight though. There is (are?) about 33 square feet of hull surface in EasyB which corresponds to 0.6875 cubic feet of ¼” strips or 0.516 cubic feet of 3/16” strips. At 22 pounds per cubic foot that’s 15# versus 11.4#. Rather than trying to save 3 ½ pounds on this boat, I’ll wait and build a really light boat (15#) on same form using 9mm PVC foam, kevlar and s-glass. So 15# hull wood, 5# epoxy/glass and say 5# bulkheads, deck and gunnels and I’m carrying a 25# boat (Actual boat weighed 26#).. This I can do.

Back to construction. Though conventional scantlings and lay-up, Easy B was built without using staples, using rubber bands instead to hold the strips against forms cut from ¼” pegboard. There was reason in having 9” (now 8”) station spacing, easy to do since the shapes are derived mathematically. Bulkheads were laid up from scrap strips with glass/epoxy both sides. Decks will be foam sandwich similar to the Bionic Log, which will allow me to indulge my minor obsession with book matching. Back when I was ripping my own strips, It was simple to rubber band strips together in pairs making it easy to book match everything. Now I’m content to just book match the decks with strips resawn to 1/16” veneers laid over a foam base. Gunnels are spaced with spacers cut from 1” popular dowels to contrast with the mahogany gunnels. The extra width using this format will allow us to not require any thwarts in the boat plus have a multitude of places to tie or fasten stuff and anchor footrest, leeboards or whatever.
EasyB has been a pleasure to use and I hope others find some of the same joy.

The Plans

NOTE: EasyB plans have been updated as of Jan 2011 - click HERE to download the latest version.

Below are the various PDF files you will need to build EasyB.

click for PDF file

Here is the overview. Click the image to download the PDF file.

 
click for PDF file

Here are the bow and stern profiles

 
Here are the station molds
click for PDF file
Fore Upper

click for PDF file
Aft Upper

click for PDF file
Fore Lower

click for PDF file
Aft Lower

Other articles by Skip Johnson:

SAILS

EPOXY

GEAR