How to Make a Spill Bucket in a Carnival Reverse Dunk Tank

Dunk tanks are a familiar part of local fairs and festivals. Traditional dunk tanks place the victim over a tank. Players hit a target and the victim drops into the tank. These are large and complex to set up and maintain. A simpler version is the reverse dunk tank.

A reverse dunk tank targets fun.

These tanks place the bucket of water over the victim. A bucket of water dumps on the victim whenever a player hits the target.

Building the Tank

  1. Insert the center of the circle cutter into the drill and tighten the drill neck. Cut a 4-inch circle in the center of the 4-by-4-foot square of plywood.

  2. Set the toilet tank on the plywood so that the hole in the plywood lines up with the hole in the bottom of the toilet tank. Insert a pencil through the bolt holes in the base of the toilet tank and mark the spots on the plywood.

  3. Remove the tank and drill 3/8-inch holes in the plywood where you marked the bolt holes from the tank.

  4. Lay the scaffold ladder on the wood and mark where the side rails of the ladder cross the wood. Drill two holes, 1 1/2-inch apart on either end of the wood where you marked the rails.

  5. Replace the tank and bolt the tank to the wood with the 3/8-inch bolts. Caulk around the hole to seal between the tank and the wood.

Building the Lever

  1. Drill a 3/8-inch hole through the 2-inch diameter PVC pipe 18-inches from one end. This is the pivot hole. Drill two more holes 1/4-inch from either end.

  2. Punch a nail through the center of the pie plate with the hammer. Paint a circle around the outside of the pie plate in red paint. Paint a circle around the hole and set the pie plate aside to dry for an hour.

  3. Insert the 2 1/2-inch bolt through the pie plate and through the hole 1/4-inch from the end of the PVC pipe farthest from the pivot hole.

Putting it All Together

  1. Cut a 20-foot length of twine. Tie one end to the flush mechanism of the tank. Set up the scaffold ladder so that it forms an arch. Set the wood with the tank on top of the arch. Push the U-bolts up around the side rails of the ladder and through the wood to secure the wood and tank to the top of the arch.

  2. Insert the 12-inch bolt through a washer then push the bolt through a hole on the ladder step. Most ladders have holes, if yours does not drill a hole in the step. Push the bolt through the pivot hole in the PVC pipe and up through the matching hole on the step above. Add a washer and nut to secure.

  3. Pull the twine from the flush mechanism and thread the twine through the last hole in the lever. Push the pie plate forward and tie the twine tightly to the other end when it is as far back as possible.

  4. Fill the tank with water. Push the pie plate and the lever moves to pull the flush mechanism in the toilet tank. This opens the flapper and drops the water through the hole in the bottom of the tank.

  5. Mark the spot where the water falls and place the chair under the waterfall.

  6. Tip

    If you have access to a garden hose, you can attach the hose to the water intake valve of the toilet tank. The tank will fill and flush just as it does in your bathroom. The toilet bowl is not required to make the tank work, but it does make a funny prop.


    Remove the wood and tank from the scaffold before moving. If using a toilet bowl with the tank, use a clean, new bowl.