How to Make Fiberglass Troughs

Fiberglass is an excellent material to use for feeding troughs. It's lightweight, strong and waterproof. Fiberglass troughs are available to purchase, but it's more cost-effective to make your own. You can customize the trough to any size and shape; the materials can be purchased at your local hardware store; and because it's cast out of a mold, you can make as many identical troughs as you want.

Things You'll Need

  • Plywood
  • Screws
  • Screwdriver
  • Saw
  • Duct tape
  • Disposable buckets
  • Paintbrushes
  • Petroleum jelly
  • Fiberglass resin and catalyst
  • Fiberglass cloth or mat
  • Auto body filler and catalyst
  • Scissors (optional)
  • Sandpaper
  • Varnish
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Instructions

  1. Making the Mold

    • 1

      Decide how large you want your trough. You should consider the size of the bottom, as well as the height and width of the walls. Animal troughs are typically rectangular.

    • 2
      The red shape at the lower right is an example of a trapezoid.

      Cut the plywood into five pieces according to your calculations: a bottom and four sides. Bevel the angles of the sides slightly, creating trapezoids instead of rectangles. The specific angle does not matter so long as all angles are the same.

    • 3
      These planters taper at the bottom because the sides are trapezoids.

      Screw the four sides together into a box, then secure the box to the bottom (large side down) with more screws. It doesn't have to be watertight; this is a basic mold shape.

    • 4

      Cover all the inner joints with duct tape to create smooth, curved corners.

    • 5

      Apply a coat of petroleum jelly to the entire inner surface of the mold as a release agent.

    Using Fiberglass

    • 6

      Cut or tear the fiberglass cloth or mat into 5-inch squares. Prepare more than you think you'll need. You don't want to run out halfway through the project.

    • 7

      Add enough auto-body filler to a disposable bucket to coat the inner surface of the mold, then thin it with fiberglass resin until it has the consistency of maple syrup.

    • 8

      Add catalyst for both products to the mixture, following the amounts listed on the instructions.

    • 9

      Paint a coat of the catalyzed filler/resin onto the entire inner surface of the mold. If it slides along the petroleum jelly, keep brushing it back into place until it thickens.

    • 10

      Allow the filler/resin layer to fully harden. This can take up to an hour if the weather is cold.

    • 11

      Mix a batch of fiberglass resin and catalyst, following the instructions on the resin. It's best to make more than you think you'll need; you don't want to run out halfway through.

    • 12

      Paint a layer of resin onto the entire filler/resin surface.

    • 13

      Lay overlapping squares of fiberglass into the resin, covering the entire inner surface.

    • 14

      Use the paintbrush to tap more resin into the fiberglass, saturating it fully. Tapping the resin helps to force out any trapped air bubbles, which will weaken the trough.

    • 15

      Add five more layers of fiberglass and resin.

    • 16

      Allow the fiberglass to fully cure until it's no longer sticky. This may take several hours depending on weather conditions.

    • 17

      Disassemble the mold to remove the trough.

    • 18

      Cut the rough edges off the top of the trough with a saw.

    • 19

      Sand the inner and outer surfaces of the trough until they're smooth. Start with coarse sandpaper. Progress to finer sandpaper on the outside, but leave the inside coarse.

    • 20

      Remove any sanding dust with soap and water. Let the trough dry.

    • 21

      Paint several coats of varnish on the inner surface of the trough to make it safe for food. Allow each coat to dry before adding the next. Drying time will depend on the brand of varnish and should be listed in the instructions.