How to Make a PVC Air Horn

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Things You'll Need

  • 3-inch PVC pipe

  • ½-inch PVC pipe

  • 3-inch to 1 ½-inch PVC pipe adapter

  • 1 ½-inch to ½-PVC adapter

  • Aluminum Flashing

  • ½ inch PVC cap

  • Threaded ½-inch PVC Coupler

  • 2 screws (any size)

  • Long funnel

  • Tape measure

  • Hack saw

  • Bench vise

  • PVC glue

  • PVC primer

  • Mallet

  • Metal shears

  • Power drill

  • Teflon tape

  • 5/16 inch drill bit

  • 5/32 inch drill bit

  • ¾ -inch paddle drill bit

  • Crescent wrench

Air horns have many uses. Boaters use them as warning signals and to make distress calls. Semi-trucks are equipped with air horns to signal other motorists. Sports enthusiasts use them at games when they like a play. Trains used single-note air horns until the early 1950s when Robert Swanson invented an air horn that can sound six notes. Use the instructions below to make an inexpensive air-horn at home.


Step 1

Measure back from one end of the 3-inch PVC pipe and make a mark at 2 1/4 inches. Put the pipe in the bench vise and make a straight cut with the hack saw. Mark the unused side of the pipe ¼ inch from the end. Put the pipe back in the vise and use the hack saw to make another straight cut.


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Step 2

Check the adapter to make sure all pieces fit together. Clean the pieces with PVC primer. Glue the 3-inch-to-1 ½-inch adapter to the 1 ½-inch-to-½-inch adapter.

Step 3

Pound the ½-inch PVC pipe through the adapter using the mallet. This will break away the lip on the adapter. Measure the ½-inch PVC pipe and mark the pipe at 18 inches. Use the saw and cut the pipe. Put a bushing on the end of the pipe. Cut off the capped end of the pipe. Remove the cap and apply PVC primer to the end of the pipe. Glue the cap to the end of the pipe.


Step 4

Cut a 4-inch square out of the aluminum flashing using the metal shears. Place the 3-inch PVC pipe on the flashing and trace the inside and outside of the pipe with the marker. Use the metal shears to cut between the lines.

Step 5

Insert the ¼-inch piece of PVC pipe into the 3-inch adapter. Insert the ½-inch PVC pipe into the adapter. Use the mallet to pound the pipe through the adapter hole. Insert the aluminum flashing in the adapter. Insert the 2 ¼-inch piece of PVC pipe in the adapter to hold the flashing in. Mark two spots opposite each other near the top of the 2 ¼-inch PVC pipe. Use the 5/16 drill bit to drill a hole in the pipe. Use the drill to insert the screws in the holes.


Step 6

Drill a hole in the slanted edge of the adapter using the drill with a 3/4-inch paddle bit. This is the air source. Wrap the threaded edge of the busing with Teflon tape. Insert the threaded edge in the air hole and use a crescent wrench to tighten.

Step 7

Tune the horn by adjusting the bell tube up and down until reaching the desired tone. Then place a small amount of super glue around the base of the bell tube. Cut the funnel end to fit the bell tube. Slide the funnel on the bell tube.