Those 3 gallon plastic "pump-up" garden sprayers--the kind that come with a wand with an adjustable spray tip--make useful fire "preventers" during harvest and are handy in the shop the rest of the year.
The adjustable tip allows the user to mist an area of equipment prior to welding or torching to prevent crop debris from catching fire during repairs. Turning the tip to "jet" gets water deep into the nooks and crannies where sparks always seem to land. Unlike traditional "dry" fire extinguishers, the volume is controllable so you use only as much water as necessary. Refilling is easy the next time you're near a water hydrant. If you keep a small bottle of hand cleaner, the little sprayers are also handy to provide water to wash your hands after messy repairs.
After harvest, a water-filled garden sprayer is handy in the shop. Rather than drag a garden hose across the shop, use the controlled spray from the sprayer to dampen areas where welding or cutting on equipment could ignite fires; to cool metal made hot by grinding, cutting or welding; and to do pinpoint wash-jobs that need only a little water. Some farmers keep in their shop a 3-gallon sprayer filled with concentrated soap solution so they don't have to mess with the built-in soap dispensing system on their power washer. After wetting equipment or trucks with a garden hose they mist the vehicle with concentrated soap from the hand sprayer, let it soak, then rinse with a power washer.
The small 3-gallon sprayers have limitations. They won't handle a full-flame conflagration. Filled with water, they are not safe to use on electrical fires and may compound problems from petroleum -fueled fires. If harvest runs into winter, or your shop is unheated, they will freeze and their plastic components will crack due to expansion of the ice. But if used judiciously in the correct situations, they're handy additions to service trucks and shops.
And, if you're not sure about the reference to "Smokey The Bear" in the title to this blog entry, ask your grandpa.