A home-made spray boom may not save you much money after purchasing all the parts, but you can make your spray boom to your own specifications, either longer or shorter than commercial booms. This boom will attach directly to your lawn sprayer, with just a few modifications made to the sprayer itself. This boom creates an efficient way to fertilize or weed-treat a large lawn or small plot of land.
Measure the hose on your lawn sprayer that connects the pump to the sprayer. Mark the hose 2 inches from the pump. Sever the hose at the mark with a utility knife.
Attach a 3/4-by-3/4 inch hex coupler into either side of the straight section of a 3/4-by-3/4-by-3/4 inch tee. On the opposite side of the tee, attach a 3/8-by-3/4 inch barbed NPT male fitting.
Connect a 3/8-by-3/4 inch barbed NPT male fitting to the open end of the 3/4-by-3/4-by-3/4 inch tee. Attach a valve to the coupler on the tee, then attach a 3/4-by-1/2 inch male NPT barbed connector to the other side of the valve.
Attach the straight side of the assembled tee, opposite the valve, to the cut end of the hose coming from the pump. Use a 3/4-inch hose clamp around the end of the hose to attach the hose to the male fitting on the tee. Tighten the clamp when the hose is attached.
Identify the side of the tee perpendicular to the side attached to the hose. Attach this end of the tee to the cut end of the hose leading to the sprayer. Use a 3/4-inch hose clamp around the end of the hose to attach the hose to the male fitting on the tee.
Mark the conduit with a permanent marker, 4 inches from one end. Starting from this first mark, make 3 more marks at 20-inch intervals. Measure 4 inches from the last mark, then cut off the remainder of the conduit with a hacksaw.
Tape or clamp the nozzles to the conduit at the four locations you marked. Cut the 1/2-inch hose to fit between the nozzles. Attach a 3/4-inch clamp to each end of the three hoses where they will attach to each nozzle, then attach each hose to the nozzle at each end. Tighten the clamps to tighten the connection between the hoses and the nozzles.
Attach the hose and nozzles assembly to the conduit at equally spaced intervals using 1 1/2-inch hose clamps.
Cut the center of the hose that falls between the two nozzles in the center. Place a 3/4-inch hose clamp over the two ends of the cut hose, then insert the straight side of a 1/2-inch barbed tee between the newly cut hose.
Place the sprayer on the trailer or off-road vehicle and measure the distance between the sprayer and the boom hookup on the vehicle. Use a utility knife to cut a 1/2-hose to this length. Place a clamp over each side of the 1/2-inch hose. Attach one side of the hose to the valve from Step 3, and attach one side of the hose to the open end of the tee in Step 8. Tighten the clamps.