Truck Air Horn

This is my first instructable so please give me any feedback you have! I will show you how to make loud air horn out of a few pieces of PVC pipe and an inner tube scrap.

* I found an old truck air horn that didn't work from a scrap guy for free and uses the bell from it on my PVC set up and it sounds real nice!

** if your boss is a sissy like mine was then its best NOT blow the horn at him when he touches your truck or you may find yourself with more "free" time to make instructables but with less income for it. yes yes I got fired for the airhorn but it was random since he knew I had the horn on my service trk and thought it funny when I got coworkers with it but not when we laughed at him for getting the horn! oh well I took it with me and will install on my personal trk which I am making into my OWN service trk and will soon take some of his customers with me out on my OWN so it was a good thing cause now IM THE BOSS and its nice.

1-funnel ($1.97 Walmart)
1-1 1/2" PVC coupler ($0.88 Lowes)
1-1 1/2" to 3/4" PVC reducer ($1.09 Lowes)
1-3/4"x12" PVC pipe ($0.97 Lowes)
1-large hose clamp ($1.99 Lowes)
1- rubber valve stem (ask local tire shop, free maybe)
tractor tire inner tube (free tire shop from junk tire)
drill
screws (3-4 3/4" long)
hacksaw
scissors

cut the "skirt" of the reducer off with a hacksaw

put the reducer into the coupler and screw it in to keep from popping off with pressure. ***be sure not to screw into the pipeline I used 1 5/8" screws hence I say 3/4" now

the reducer has a small lip that needs to be filed or ground down so the PVC can slid fully thru it. I uses the drill and the bit to remove it

drill a hole for the valve stem near the middle of the coupler. I believe its 3/8" but don't quote me

lube the stem with cooking oil or other lubricant and pull it thru the hole till its nice and snug. you should feel ur kind of pop into place

put your hose clamp on the tube scrap and mark 1/2-5/8" WIDER than the clamp and cut it

put the tube over the coupler (not the reducer side with the screws) then put the clamp over it and push down till it can be tightened and air tight

insert the 3/4" PVC tubing til it stretches the tube and you see it make a ring in the center of the tube

cut the PVC pipe down if you like the longer it is the deeper but quieter it is the shorter it is the louder higher sound will be produced. once you selected the length (I usually cut it 3-4" from the reducer) cut the funnel so its super snug over the PVC pipe. now you may with to tape it in place if its too loose but before you tape it hook the horn to air and slide the funnel back and fourth on the tube till you get the desired sound of your liking. once you have the sound you like tape the funnel in place and mount via zip ties, hose clamp or tape to its place of operation.

you can hook the hose to a valve like an on/off style, a manual trigger style (like blow nozzles) or if you have a lil $$$ you can get an electric over air relay box (best for cars and trucks I have one on my service truck with 1 horn and I spray painted it to blend in and I've been scaring coworkers for almost 2 years in the elements with it ) you may want to make 2-3 horns of different lengths and sizes and run them together for a dual or tri tone sound. hope you enjoyed this and always experiment with things