Union's 2000 Concrete Canoe


1. 1 foot stations were plotted, then attached to plywood. These would become the cross sections of the canoe.
2. The plywood cross sections were attached to the strongback
3. 2 by 4's were used to hold the sections to the strongback
4. Care was taken to insure the sections were straight
5. By sanding the sections the desired shape was achieved, and bumps were smoothed
6. Wood strips were stapled to the cross sections to complete the male mold
7. The canoe was stripped in three sections, with the bow and stern section completed first.
8. Then the middle third of the canoe was stripped
9. Many measures were taken in order to obtain a smooth interior and exterior surface. The strips were sanded and planed
10. Then dry wall compound was applied to the mold to fill in spaces and create a smooth surface.
11. In order to make sure the take down mold would come apart, cuts were made in the dry wall compound layer to separate the three individual pieces.
12. Foam was placed at the bow and stern to complete the shape of the canoe.
13. Shrink-wrap was used to keep the concrete from bonding to the mold
14. This also helped to smooth the interior canoe surface
15. Steel wire mesh was used as the primary support for the canoe. No spacers were used. Instead the mesh was held to the mold with nails that were extracted during the pour.
16. Ceiling tiles were used as the main aggregate. The day before they were weighed out by batch...
17. The ceiling tiles were then broken up into smaller pieces and soaked for one hour.
18. The tiles were then pulped and placed in plastic bags in order to retain moisture. By doing this the next day's process of pouring the canoe was more efficient.
19. Batches were made on the day of the pour from the pre-pulped ceiling tiles, and the cement, which had also been weighed the day before.
20. Union's ASCE members volunteered to help the on day of the pour.
21. The pour began at the bow of the canoe, by forcing the concrete through the steel wire mesh. The three hour process of pouring the canoe slowly moved toward the stern.
22. A vibratory sander was used to help force the concrete through the steel mesh.
23. Wires were cut and marked in order to insure the thickness remained uniform throughout the canoe
24. A pipe was used to smooth out the exterior surface of the canoe before the final mesh was placed.
25. When the canoe reached it's desired thickness a layer of fiberglass mesh was placed to complete the double layer system.
26. A very thin layer of concrete covered the fiberglass mesh in order to create a smooth hull surface.
27. The canoe was then wrapped in wet burlap, which was re-soaked on a daily basis. This allowed the canoe to hydrate.
28. A plastic sheet was placed over the burlap to reduce evaporation. The canoe was allowed 2 weeks to hydrate before preparation for finishing began.
29. Floatation was added for two reasons, First – it allowed the canoe to pass the swamp test at the competition since the unit weight of the concrete is not less than that of water. Second – It allowed for a Polynesian look.
30. The canoe was then painted to resemble a tropical sunset.

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