How to Make a Venturi Stream

Place the funnel, with its large diameter facing down, flat on a work space. With the hacksaw, gently start cutting a lengthwise slot through the center of the spout. The cut should go through the near and far walls of the spout. Stop the cut a quarter inch from the conical portion of the funnel. Turn the funnel 90 degrees and make another cut.

Cut a length of clear vinyl tubing 6 to 12 inches long using the utility knife. Make the cut perfectly square or perpendicular.

Straighten your hose by bending it in the opposite direction as its natural curve. Coiled storage of hoses leaves this curve. Bend it back and forth several times, removing as much of the curve as possible.

With your screwdriver, adjust the diameter of your hose clamp so it is slightly larger than the tubing. Slide the hose clamp over the tubing. It should be loose enough to move along the length of the hose with your fingers, but snug enough it won't easily fall off.

Slide the vinyl hose over the slotted funnel spout. The fit may be fairly snug. You can help the process with a little mineral oil or other lubricant if necessary. The slots you made should relieve some of the pressure. Continue sliding the hose as close to the conical tip of the funnel as you can. It should get quite snug in the last quarter inch.

Slide the hose clamp over the tube and spout joint. You may have to loosen the clamp slightly as the hose diameter may have stretched a little as it was installed. With the clamp aligned a 1/4 inch from the conical end of the funnel, now snug the clamp down, but not too tight. Make it snug or finger-tight.

Test the venturi by blowing a stream of compressed air through it or use a fan. To observe the venturi effect, you can even drop confetti into the air stream and watch it accelerate in your venturi stream.