iron shovel

Iron Shovel, Before Treatment (Recto)

Both sides of this shovel were caked in dirt and powdery corrosion product. X-radiography previously done by another student revealed details such as rivets or nails which were not visible before treatment.

Iron Shovel, Before Treatment (Verso)

Iron Shovel, During Treatment

The corrosion layer was light and powdery in upper layers, but much more compact towards sound metal. Brushes, scalpels, swabs, and cosmetic sponges were used to carefully remove the crust, revealing the shovel's surface. Some areas were were delaminating and flaking due to corrosion.

Iron Shovel, During Treatment

Some severely flaking and delaminated areas were consolidated using 5% B-72 in 3:1 mixture of acetone to ethanol.

Iron Shovel, During Treatment

After corrosion reduction.

Iron Shovel, During Treatment

Two coats of tannic acid were applied to both the recto and verso of the shovel in order to passivate active corrosion and tone down the bright orange colour of the shovel's surface where some corrosion remained.

Iron Shovel, During Treatment

Colour change was most noticeable after the shovel had dried and a stiff-bristled brush was used to brush away excess light beige ferric tannate particles of the surface. Here, ferric tannate flakes have been brushed away from the lower half of the shovel head (left side of the photo) after the second coating of tannic acid.

Iron Shovel, During Treatment (Verso)

A third coating of tannic acid was locally applied in some areas to make the overall colour of the shovel more uniform.

Iron Shovel, After Treatment (Verso)

Iron Shovel, After Treatment (Recto)

This shovel was excavated from the Hudson's Bay Company Moose Factory Staff House site in 1979. A thick, bright orange crust covered the surface of the shovel, obscuring all details of its original surface.

The goal of this treatment was to excavate the surface of the shovel and reveal sound metal, stabilize flaking areas, and passivate active corrosion.

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