How to Make Kayaks Through Rotational Molding

Kayak manufacturers use rotational molding to build durable plastic kayaks. (See Reference 1). During the rotational molding process, a metal mold gets heated, which melts the plastic inside the mold to coat it. Before any rotational molding takes place, the manufacturer designs a boat, builds a plug, which is an exact replica of the final kayak, and makes a mold. Any manufacturer doing rotational molding must invest in large ovens and rotational equipment to complete the process.

Things You'll Need

  • Mold
  • Rotational Oven
  • Powdered polyethylene
  • Color additives
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Instructions

    • 1

      Install the kayak mold into the rotational oven. Ovens vary, so follow the proper instructions.

    • 2

      Fill the mold with the right amount of powdered polyethylene, which varies based on the size of the kayak and thickness of the kayak's hull. Add color additives to make the kayak the desired color.

    • 3

      Close and lock the mold according to the instructions.

    • 4

      Start the rotational oven. It rotates in two perpendicular directions, which spreads the powder evenly around the mold.

    • 5

      Turn on the oven's heat source. The heat source melts the powder and color additive. The melted polyethylene adheres to the mold's walls.

    • 6

      Continue rotating the mold until the melted powder becomes a sheet of plastic.

    • 7

      Allow the mold to cool to touch.

    • 8

      Open the mold and pull the completed kayak out.