By Darrell Boone
Finding a window to spray when all conditions are right is already tough and getting tougher. The last thing you need is to finally have all conditions “go,” and then find out you have a sprayer problem because you didn’t properly winterize it last fall.
“It can take a lot of time and effort to properly winterize your sprayer, but avoiding doing so, or doing a halfway job, can get real costly,” says Fred Whitford, director of Purdue University Pesticide Programs. “That’s just part of your job as an equipment owner or operator.”
Whitford says the first step is reviewing the owner’s manual. By following its instructions, you’ll be able to keep your equipment covered by the manufacturer’s warranty.
One of the most crucial tasks is getting as much water and residue out of the sprayer as possible. It’s especially important to remove any chemical residues — either in or on the sprayer — before they form a hard layer on tank walls, screens, elbows and corners. These residues can also dry in rubber hoses, which makes them extremely difficult to remove if they remain on the sprayer until spring.
Whitford says it’s essentially impossible to get all of the water out of a sprayer. But once you’ve cleaned and flushed the tank, spray as much water out of the system as you can until the pump no longer has enough water to push out of the tips.
Open valves, use air pressure to force water in the lines out toward the nozzle tips, and drain the pump. Tipping spray booms to a 45-degree angle can help remove more water.
Next, add antifreeze. For any water that’s still trapped in your sprayer’s system, Whitford says it’s imperative to use antifreeze. Don’t use brands recommended for automobile use, because they contain rust inhibitors that could damage your sprayer’s plastic parts and pump seals.
Instead, Whitford recommends using RV antifreeze as an inexpensive and effective alternative. Another option is to use windshield washer fluid, which is even cheaper. But make sure it’s winter washer fluid that will protect your sprayer at colder temperatures.
Add one and a half to two times the amount of antifreeze as your sprayer’s plumbing. Then keep the antifreeze going through the system until the color coming out nozzles is the “full strength” color of antifreeze.
Finally, check hoses and clamps. Whitford says hoses essentially function as your sprayer’s “arteries,” moving chemicals from the tank through the pump, out toward the boom and eventually through the nozzles. If a hose fails, not only will it cost you lost time and product, but it can also create an environmental hazard.
Most accidental releases of pesticides or hydraulic oils are a result of hoses that burst or blow off fittings when clamps fail. Thoroughly inspecting all pressure hoses and clamps should be part of any routine equipment maintenance program. Specific areas to check include:
Hoses rubbing against something. Abrasions to a hose will weaken it, eventually causing it to form a bubble and burst. Possible remedies include rerouting the hose so it no longer rubs or putting a protective sleeve around the hose at the point of contact. If the hose is seriously compromised, always replace it.
Hoses that are degraded by sunlight or heat. Replace any hose that appears to have dry rot.
Hoses that are soft. Diesel fuel or oils can saturate a hose, softening the rubber. Unlike gasoline, diesel fuel doesn’t evaporate quickly. Fix the leak, replace and reroute the hose.
Hoses with constrictions such as kinks. This reduces flow. It also can weaken the hose at the restrictive point.
Purdue Pesticide Programs
FIND AND REPLACE: Why start the season with a hose like this on the sprayer? Likewise, when you’re preparing the sprayer for storage this year, replace such a hose so it’s ready for next year.
“It’s a good safety practice to annually replace the pressure hoses that carry solution,” Whitford says. “The cost of replacing a hose is pretty cheap, compared to the cost to the environment and the cost of cleaning up when a hose fails.”
Any clamps that are seriously rusted need to be replaced immediately. Standard worm-gear hose clamps are the most popular type. As they’re replaced, use new clamps that have stainless steel bands, screws and housings. Some operators choose to use two worm clamps as an extra safeguard. Offset the tension portion of the clamps opposite each other by 180 degrees.
Whitford recommends T-bolt clamps as replacements, if possible. While more expensive, they offer a heavier-duty design and rigid frame to retain a tighter and more uniform fit.
Boone writes from Wabash, Ind.