Updated date:

Building a Cedar-Strip Canoe, the Details: Lofting the Plans

Author:

Jim is a retired software/electrical engineer who enjoys the outdoors. He likes to challenge himself with creative projects at home.

building-a-cedar-strip-canoe-the-details-lofting-the-plans

This is the first of a new series of articles documenting the details (as diligently as I can) of building my next cedar strip canoe. I cannot guarantee new information will flow onto these pages very quickly but as I proceed I will add new articles. The descriptions will be my own words and experiences (and mistakes) as I proceed with the build.

If you plan to build a canoe I would advise purchasing a book. It will contain much more information than I intend to provide here.

I decided to build another canoe of a different, more modern design. I chose the Freedom, which is a non-traditional shape with an efficient asymmetric hull. This means the hull has a sharper taper from the center toward the bow than it does from the center towards the stern. The slimmer forward profile helps increase speed while the wider aft section helps improve tracking. So goes the theory. My goal is build this canoe somewhat lighter than my last, although I still want it to be rugged enough for canoe camping and wilderness trips. I am thinking 55 lbs is a good target.

Choosing a Design

building-a-cedar-strip-canoe-the-details-lofting-the-plans

So the first step was to choose a design, which I have done. I selected it from the various designs provided in Canoe Craft, though I will shorten it by about a foot.

The next step is to transfer the numbers in the tables onto paper so that the shape of the hull can be traced onto plywood for the forms. This process is called "lofting."

building-a-cedar-strip-canoe-the-details-lofting-the-plans

Lofting

building-a-cedar-strip-canoe-the-details-lofting-the-plans

I will describe what I did, but another description is available at the link below. On a large sheet of paper layout a grid of 2 inch X 2 inch squares. About 18 horizontal and 10 vertical. Mark a baseline and a centerline. The horizontal lines are water lines (WL) and the vertical lines are buttress (butt). Since the hull is symmetrical side to side only one half of the hull needs to be plotted to define it's shape. Once the first half of the hull is traced for a particular station, the outline plan for that station can be flipped about the vertical center line to trace the other half. Station lines tend to get crowded together near the center of the hull bottom so it would be a good idea to draw half of the stations on the right of the center line and the other half on the left. Or use more than one sheet of paper.

An example of a plot for station 8 is shown above. Measure from the center line along each horizontal water line for the "WL" values in the offset tables, then make a mark. Measure each vertical buttress line for the "butt" values in the offset tables, then make a mark. For the sheer draw a horizontal line at the distance from the baseline given in the table of heights. Then use the distance given in the table of half-breadths to mark the sheer along that line. The stem plots are created the same way by just using the WL gridlines.

Creating Templates

building-a-cedar-strip-canoe-the-details-lofting-the-plans
building-a-cedar-strip-canoe-the-details-lofting-the-plans

My plan for the next step is to trace the half hulls on poster board to create templates for transferring the hull outlines to the particle board which will be used for the station molds. At the bottom of each station there needs to be a portion that will hold the station moulds above the strongback and which will allow the stations to be attached to the station blocks on the strongback. I plan to use about a 4-inch extension on each mold.

Shown is the strongback from my last project. It has the station blocks attached.

building-a-cedar-strip-canoe-the-details-lofting-the-plans

The Basics

  • Building a Cedar Strip Canoe: The Basics
    A practical account of my experiences and a brief guide to building a cedar strip canoe. It includes links to stories of using the canoe for wilderness camping and fishing.

The Next Step

The Other Steps

Comments

jimmar (author) from Michigan on October 21, 2018:

They do not need a bead and cove, but they will need a bevel so they meet flush. I believe it is called a "rolling bevel" since the angle changes along the length of the strip. I have never tried this but some say it works well. Seems complicated to me.

Al on October 21, 2018:

do the stripes need to be milled with a cove or can I just butt joint the full length of the stripes

Johnd809 on July 20, 2014:

I got what you mean, regards for putting up.Woh I am delighted to find this website through google. You must pray that the way be long, full of adventures and experiences. by Constantine Peter Cavafy. ceekfecfbeed