DIY Compressed Air Fog Horn

Foghorns have uses on land as well as at sea.

Foghorns, an essential piece of equipment for navigation, use loud sounds to provide warnings of hazards. When lighthouses are obscured, foghorns warn boats of headlands, rocks and other hazardous situations. Although you can purchase a foghorn, it may be more cost effective and educational to build your own compressed air foghorn with basic supplies. This do-it-yourself foghorn uses compressed and pressurized air to create an audible sound similar to the fog horns used in marine transport.

Things You'll Need

• 40 to 50-psi air compressor
• Air horn
• 6-inch PVC pipe
• Elbow PVC pipe
• 5-gallon portable air tank
• 1 foot of rubber tubing, 1/2 inch diameter
• Brass clamp fittings, 1/2 inch diameter
• Teflon tape

Instructions

1. Connect the air compressor to the 5-gallon portable air tank using the hoses provided with the air tank and compressor. Attach one end of an air hose to the air compressor and the other end of the hose to the air tank. Secure the connections with teflon tape to prevent air leaks.

2. Affix the air horn to the 6-inch PVC pipe with Teflon tape. Connect the elbow PVC pipe to the unoccupied end of the 6-inch PVC pipe.

3. Join the rubber tubing to the air compressor with brass clamp fittings. Screw the brass fittings over the tubing tightly. Secure the connection with teflon tape.

4. Attach the free end of the rubber tubing to the unoccupied end of the elbow PVC pipe.

5. Turn on the air compressor and air tank to allow the air to flow through the rubber tubing and into the air horn. Use different amounts of airflow to experiment with various sounds.

Tips & Warnings

• Air leaks will cause the foghorn to malfunction. Ensure that any connections are secured with teflon tape.

References

• Gizmodo: The DIY Foghorn that Never Dies
• ROG8811: Home Made Foghorn