What are the key areas to watch out for when buying a second-hand crop sprayer
As soil temperatures increase over the coming weeks, attention will turn to planting. This week I take a look at some of the things to watch out for if in the search for a decent second hand crop sprayer.
It's well and good getting a bargain, but not at the expense of a sprayer that doesn't function when required. Would you be confident looking at a used sprayer and checking the parts that can typically give trouble? Irrespective of marque most brands of sprayer share the same types of systems so the areas of concern will be similar.
The main areas to look at are the type of pump, the boom and nozzle quality, and the controls (specifically whether they are electric or manual). If a farmer/dealer is serious about selling a sprayer, he will hitch it on a tractor and run it for you. This will show the condition of the pump as well as the state of the nozzles. It will also identify any leaks on fittings and show where there are cracks in pipes.
The heart of the sprayer is the pump. There are three types of pumps; Diaphram piston pumps, piston pumps and centrifugal pumps. Piston pumps and centrifugal pumps can do a higher amount of acres before they need maintenance. If the oil in the pump is a creamy colour then the pump needs to be reconditioned.
This can be easily identified by a sight glass fitted on most sprayers or by check by examining the dipstick. If the sprayer is suffering from abnormal pressure, it may be down to: damage to the diaphragm, valves or seals in the pump.
Alternatively, it may be caused by a blocked valve or inlet pipe. For those buying privately, it would pay to have some cash in reserve in case the pump would need to be reconditioned.
Check the sprayer for wear on the nozzles. If you don't know the history of the machine, replace all the nozzles. Wear on nozzles can be identified by an uneven spray pattern. Failure to replace these faulty nozzles will compromise output and waste expensive chemical. It is also worth checking the filters for the nozzles as well, as these may need to be replaced.
Check the condition of the boom. A crack in the structure of the boom, rust and play in the hinges and joints of a sprayer are the main things to watch out for. Too much play in the boom will mean poor distribution of chemical. Fold out the boom and measure the height of the boom at different points. Height difference should be less than +/- 60mm. On used sprayers, damage would normally occur from the boom hitting off obstacles in the field. In general though, booms are strong. Check that the break back mechanism is working. If it is seized, it can result in further damage in the event that the boom hits an obstacle. It's also important to check if the boom pipes are firmly attached to the boom.