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Constructing Ponderosa included the following phases: strong back construction, mold construction, pouring, and finishing. The construction phase required great attention to detail to create a canoe that would aesthetically surpass previous teams’ canoes. In order to increase sustainability and comply dimensionally with the NCCC rules and regulations, a female wood strip canoe mold was used.
An excessive amount of engineering went into the design and construction of the mold. The mold was constructed with plywood strips, laid lengthwise, glued together and screwed to 20 male cross sections. If needed the mold was designed to split in half, ensuring the release of the concrete from the mold. A fiberglass mesh and epoxy resin was applied to waterproof and strengthen the mold.
Before the concrete was poured a releasing agent was applied to the mold to release the concrete. The concrete was poured with the assistance of over a dozen NAU ASCE members using trowels and large metal spoons. Three layers of concrete were laid down with a layer of fiberglass reinforcement between each layer of concrete for a combined thickness of ½ inch. For aesthetics, two Styrofoam bulkheads were encased in concrete at the bow and stern. Additionally, two ribs were added at equal distances from the bow and stern.
The concrete was given 28 days to cure in a 100% humidity environment. After seven days of curing, various tasks such as sanding, patching, and pouring of the gunwales were completed.
After the curing was complete, imperfections were patched and given approximately three days to cure before being sanded to a smooth finish. Murals were stained on the concrete canoe’s hull exterior and interior using a water base concrete sealer with added pigments. The school name and the canoe name were painted with the aid of stencils created from AutoCAD. When all the artwork and lettering was finished a “clear wet look” concrete sealer was applied.