Looking Closely: Treatment of a Birch Bark Canoe. (Part One)

The Canadian Canoe Museum has taken the first steps in the conservation of an 18th century birch bark canoe. This canoe has only recently returned to its country of origin after laying in Cornwall England for over 200 years. Through a Fleming College internship placement from the Cultural Heritage Conservation and Management program, the museum has put intern Lauren Tregenza to work on the preliminary stages of this project. This is an important first step for closer analysis and treatment of this historic birch bark canoe.

The closer I looked at this 18th century watercraft, the more questions and mysteries arose. When I first encountered the canoe I remember being struck by how beautiful the damaged remains were. The canoe appears almost skeletal, revealing glimpses of the inner rib structure. The bark has faded to a pale tone which gives it an almost ghostly feel. After this initial impression, I began to look more closely at the condition of the artifact and recorded these observations in what museums call a ‘condition report.’ This stage feels like detective work. I use various tools such as a magnifying glass, a handheld microscope and macro photography. This first step in conservation treatment can aid in the understanding of an object through careful inspection, documentation and analysis.

This act of looking is informed by knowledge of the materials that the object is made out of. In this case the materials are birch bark, cedar, spruce, iron, resin, pigments, canvas and potentially other unidentified materials. The more materials an object is composed of the more complicated is its condition. Each material has its own tendencies and vulnerabilities. All these factors play upon each other and have influenced the current state of this birch bark canoe.

In addition to these shifting components are all of the scrapes, fractures, holes and stains that the object now carries. Some of these elements can be improved upon, some may be irreversible and some illuminate secrets concerning manufacture or use. Full restoration is not always desirable, as this can harm the aged materials of the object and erase the stories that old scars may provide. Treatment details will be discussed in Part Two of this series.

Birch bark canoes are ephemeral objects if left exposed to the elements, which is why there are not many old examples. This canoe could potentially be one of the oldest examples available at over 200 years old. When looking at construction techniques, the canoe also has many stories. Traditional birch bark canoe building techniques were used to build the original object.  Not all aspects are traditional however. The ends have been repaired and covered in canvas which has been skillfully painted to match the bark in colour and texture. There is another repair where a thick canvas patch has been wrapped around a portion of the hull. All these elements are now a part of the history of the object.

 Tune in for part 2 of this series which will detail the conservation treatment of this canoe.

 

Key to dimensional changes diagram.

a.     Gunwales: Want to straighten to their original form, are no longer held in place by lashings.

b.     Spruce root: Will become brittle and loose the necessary strength to bind the structure. This causes the gunwales to separate from the structure.

c.     Ribs: Are expanding horizontally over time, since there is no pressure being exerted on them by the now fractured gunwales. This action pushes out the gunwales and stresses the birch bark cover.

d.     Birch bark: Will curve in upon itself as moisture moves through the bark.

e.     Previous Repairs: Canvas covered ends and older repairs near the centre.

f.      Sheathing: As the canoe unravels, large sections of sheathing are loose. Sheathing should be held in place between the ribs and bark cover through pressure.

g.     Thwarts: They are missing. They would have helped to counteract the force of the ribs pushing on the hull.