Art. I. On the Construction of Birchbark Canoes, by Mr. J. Gottfred.
During the summer of 1995, I had the opportunity to spend several days in the canoe shed at Old Fort William in Thunder Bay, Ontario. During this time I observed all aspects of the construction of a North canoe using only historical methods, materials and tools. Birchbark canoes are constructed in a manner quite unlike normal boats. In a typical vessel, such as a York boat, the keel and ribs are constructed first, and then the skin of the vessel is placed over them. In the construction of a birchbark canoe the skin is sewn to the gunwales, then the ribs are inserted, stretching out the birchbark to form the final shape of the canoe.
In this article, I'll look at all the aspects involved in constructing a birchbark canoe, a task which took the canoe builders at Old Fort William only seven days from the cutting of the rind to the launching of the canoe.
Preparations for Construction
Canoes are not made by eyeball ; instead, their construction is controlled by two templates. The first template shows the shape formed by the gunwales of the canoe. The second template shows the length of the central and largest rib in the canoe. The tricky part in canoe building is to get the correct dimensions for these templates. To build a canoe yourself, you would have to build several models in order to determine the dimensions of these components.
Once you have the templates, you're ready to proceed with collecting the materials. The basic materials for such canoes are birchbark for the outer skin, white cedar for the gunwales and ribs, watap, (spruce roots) for sewing the canoe, and a spruce resin compound for gumming. Each of these materials will be discussed as the details of construction are covered.
The skin of the canoe is made of the outer bark, or rind, of the birch tree. The bark of a birch tree consists of two distinct layers: the outer bark and the inner bark. The outer surface of the outer bark is white and papery, but the bulk of its thickness is an orange tough leathery material marked with shallow horizontal grooves. The inner bark is more yellowish in color. It is spongy and cracks easily into small chunks. This inner rind is the living layer of the tree. Underneath this living layer is the hard heartwood of the birch.
Canoe Bed— A canoe under construction at Old Fort William. The gunwale template is held tightly in the bottom of the canoe by the vertical pole. The birch rind has been pulled tight around it and clamped between the gunwales, which have then been bound with watap. The ribs will be inserted once the template has been removed from the canoe body. Note that the silvery-white outer bark is on the inside of the canoe.
The object in harvesting birch rind is to remove only the outer bark, leaving the living layer intact. This can only be done during the hot months of summer, and is best accomplished during the heat of July. The bark is stripped by making a vertical slit down the length of the tree, prying back the outer rind, and then cutting horizontally around the tree only through the outer rind. The outer rind can then be peeled from the tree in huge continuous lengths ideal for the manufacture of canoes. As long as the tree is not girdled and the living layer is not damaged, the tree will survive. It soon makes a scar-like tissue on the outside and may continue to thrive, but it can never be harvested again. I saw strips of birch rind four feet wide and eighteen feet long that had been removed from trees this way. Trees that had been treated in the same fashion years ago were still doing fine. David Thompson says that strips of two to two-and-a-half feet wide and nine to fifteen feet long were typical in his day (Thompson, Narrative, 97).
Birch Rind— This roll of birch rind is four feet wide and a dozen feet long. One of the pieces in the background is eighteen feet long.
The HBC's Andrew Graham (c. 1772) remarked that
'[The Indians] observing the bark to be thicker on one side of the tree than on the other, they make the incision down the thinnest side, reserving the strongest part for the bottom of the canoe, where it is most wanted.' (Thompson, Columbia, 203)
Once the rind has been removed from the tree, it must be rolled with the white outside of the rind inwards, and it must be rolled along its length from top to bottom, against the natural curl of the rind. In short, roll it in a manner completely opposite to its natural curl. If it is allowed to curl naturally, the inner surfaces will knit and the bark will be useless. It will stick together and you will not be able to unroll it. For canoe construction, the outer rind must be no less than 1/5" thick. Thinner rind can be used for baskets and similar items, but canoes need tougher material.
The harvested rind is soft and supple, very much like tough leather. In a direction along its length (perpendicular to the grooves in the bark) the rind is almost impossible to tear. However, in a direction parallel to the grooves (across its width), the bark is easier to tear. The harvested rind will remain supple and easy to work with for up to a week, depending on the temperature and humidity.
Watap is the root of the spruce tree. To collect watap, you must find a swampy or sandy area where the roots of the trees can grow in long straight lines. In stony ground, the roots bend to go around the rocks and as a result are too crooked to be of use. Under the right conditions, long lengths of spruce root can easily be pulled from the ground. The watap must be de-barked before use. This is accomplished by soaking it in water and pulling it through a plank with a notch cut in it. Watap is surprisingly strong and it is usually split in half prior to use to make it more supple.
Watap De-barking Jig— Lengths of spruce root are simply pulled through a notched board in order to remove their bark.
Canoe Bed— Close-up showing the birch rind sewn between two white cedar strips which form the gunwales.
Sewing the Rind to the Gunwales
Construction of the canoe begins with the forming of the 'canoe bed'. The rind is laid out with the gunwale template on top of it. The rind is then pulled up around the template to the gunwales and clamped at some distance, as determined by the template, above the bottom of the bed. If the birchbark is not wide enough, then additional strips must be sewn along its length in order to make up the proper width. If the bark is not long enough, extra pieces are overlapped in order to make up the difference. These joins do not require sewing due to the force of the canoe ribs. Note that the white outer side of the rind is placed on the inside of the canoe. The gunwales are formed of two strips of white cedar between which the bark is sandwiched and sewn. Cross bars are added to keep the gunwales apart.
At this stage in the construction the canoe has a square profile, i.e. flat sides and bottom. Once the skin has been sewn to the gunwales, the template is removed and the ribs are inserted to create the canoe's classic round bottomed shape.
Watap Sewn Gunwales— This detail shows the skin of the canoe sewn to the gunwales. Note the additional reinforcing strip cut with a decorative scallop pattern. The stitching in the lower portion of the illustration shows the seam sewn with watap between two lengthwise strips of rind.
Where the bark meets the gunwale, the force on the sewing is in a direction parallel to the grooves in the bark, so this edge must be reinforced with a horizontal strip of bark with the grooves running parallel to the gunwale through which the sewing passes. The sewing is done with watap. This reinforcing piece of bark is usually cut into a decorative pattern, and is placed on the outside surface of the canoe skin. Eight wraps of the watap are made around the gunwale and through the bark and then a gap is left to leave room for the ribs to be inserted later. The illustrations show the canoe skin being attached to the gunwales. Note the use of the gunwale template on the bottom of the boat.
The ribs are formed from white cedar planks which have been split from the log. You cannot use sawed planks, as the cedar will not bend properly if it doesn't follow the grain. (In the West, heavier pine was used for the gunwales and ribs where cedar was unavailable (Tyrell, 452-453, Thompson, Narrative, 59, Henry 467.)) There is a simple trick to get a plank of even thickness: if your plank begins to thin too much when splitting, place more force on the thicker part to move the split back into the thicker material. The split cedar planks are now placed on a bench and are thinned and made even with a draw knife. Each plank should be about 4" wide and 3/8" thick—just experiment a bit with the particular material to determine the corrrect thickness. The length of the first plank is determined by the rib template.
The planks are now placed into a steamer for several hours until they are supple enough to be bent. The longest rib is then bent to shape and its two ends fastened together to form a horseshoe shape (see illustration).
Rib Steamer— A large iron box hung over the fire is used to steam the ribs so that they may be bent to the correct shape.
Canoe Ribs— The ribs are bent and nested one inside the other to form a natural taper. This jig already has two ribs in place.
The remaining planks are bent and nested inside the first rib. This clever trick results in a series of ribs which will produce the classic tapered canoe shape. Note that two sets of such ribs are required— one set for the center to the bow, and a second for the center to the stern.
Once the ribs are dried, they are removed and their ends are tapered and shaped so that they will fit between the gunwale boards between watap bindings. Once the ribs are in place, the canoe is ready for gumming.
Note that where birchbark pieces overlap from bow to stern, they are not sewn. The birchbark pieces are only sewn together when they overlap along the length of the canoe.
Making Gum— Clockwise from top : box of spruce resin, strips of watap, frying pan with gum, combination pot holder and resin cleaning bag, tallow.
There are three ingredients in the gumming compound : spruce resin, tallow, and charcoal. To collect spruce resin, you must take a hatchet and make many cuts on the surfaces of several dozen spruce trees during the warm seasons. Return two to three weeks later with a bag, and collect up all the thumbnail sized blobs of sap that have oozed from the wounds. Place the spruce sap into a canvas bag and tie the bag securely at the top. Drop the bag into a kettle of vigorously boiling water and work the bag with a stick in order to squeeze the hot resin out through the weave of the bag. Make sure the water is boiling vigorously. The purified resin will float to the surface, and the rolling action of the boiling water will form it naturally into balls. This will remove all the bits of bark and bugs that have stuck to the sap. The finished product, once cooled, is a yellowish crystalline-like substance with a white frosting.
Gummed Canoes— These two canoes have been properly gummed and are ready for the water. The top canoe is a full size, 36 foot Montreal canoe with a 6000 pound cargo capacity (not including paddlers). Only four men are required to portage the empty canoe.
By itself, this resin is far too brittle to be used for gumming a canoe. To make the gum, place the resin in a frying pan and add tallow (suet) and pulverized charcoal. Stir and melt until the gum is a black, easily worked mass. Determining the proper mix is a matter of trial and error. The finished product, when warmed by the fingers, is plastic and slightly sticky. When cooled, it becomes hard and even slightly brittle. The warm gum is liberally applied to all the birchbark seams on the outer canoe surface. It works, but it's miserable stuff and it's easy to see how in rough water the canoe would bend and flex enough to make large chunks fall off. There's no doubt in my mind that re-gumming a canoe would have been a daily, if not hourly, endeavor.
In only seven days, three men, dividing their time between building the canoes and answering the questions of curious tourists, built a 25' canoe capable of carrying 3,000 pounds of goods that could be portaged by only two men!
Old Fort William sells any surplus finished canoes to historic sites and museums all over the world.
To see the canoe builders in action, visit Old Fort William during the Great Rendezvous held at the site every summer. (Watch Upcoming Events for more information.)
North Canoe— This finished canoe is ready to be loaded. The bow has been decorated with the letters NWC in a white circle.
Henry, Alexander (the Younger). New Light on the Early History of the Northwest : The Manuscript Journals of Alexander Henry... Elliot Coues (ed.) Reprint-Ross & Haines : Minneapolis, 1965. Originally published 1897.
Thompson, David. David Thompson's Narrative, 1784-1812. Glover, Richard (ed.) Champlain Society : Toronto, 1962.
Thompson, David. Columbia Journals. Barbara Belyea (ed.) McGill-Queen's : Montreal, 1994.
Tyrrell, J. B. (ed.) Journals of Samuel Hearne and Philip Turnor. Reprint : Greenwood Press : New York, 1968. Originally published 1934.
Copyright 1994-2002 Northwest Journal ISSN 1206-4203. May I copy this article for my class?