Boom Sprayer Technique

Discussion in 'Pesticide & Herbicide Application' started by GravelyGuy, Jun 27, 2007.

  1. GravelyGuy

    GravelyGuy LawnSite Silver Member
    from Indiana
    Posts: 2,517

    I just picked up an account yesterday that is 60,000 square feet. This will be my biggest one yet. Up until now I have been using my gas powered Echo backpack sprayer to spray for weeds and then my Shindy spreader for fert. There is no way I want to backpack spray this entire yard. It is on horrible shape right now. I went to the TSC store and I bought this yesterday on sale. How will this work out? How even do you think the application wil be? I will be using Trimec as my broadleaf herbicide and I will still spread the dry fert. Any tips or techniques are welcome. I have it filled with water right now and I have been trying it out. It seems like it is going to be hard to get up close to the house and any flower beds. I still may have to use the backpack for these areas.

    This is my first year doing applications and so far my lawns have been looking good with the backpack, but this one is just to big. I am nervous trying to use this on someone elses property. Here are some pics. Thanks for any help.

    Also, one more thing. Is there anyway that I can prevent the tips from dripping after I shut it off? They drip until the line is empty. I don't want to burn the lawn anywhere.

    Sprayer 001.jpg

    Sprayer 002.jpg
  2. Grandview

    Grandview LawnSite Gold Member
    from WI
    Posts: 3,251

    Use nozzle bodies with a diaphragm to prevent dripping.
  3. GravelyGuy

    GravelyGuy LawnSite Silver Member
    from Indiana
    Posts: 2,517

    Can I get these at TSC? When you say diaphram, is it like a piece of rubber in the nozzle?

  4. Ric

    Ric LawnSite Fanatic
    Posts: 11,956


    Ground Speed is important when calibrating your sprayer. Check out your local Bicycle shop for a reasonable priced Speedometer. It is not important that the speedometer tells the true speed so much as it helps you keep the same speed. Tracking dye will help you from over lapping or missing areas.
  5. GravelyGuy

    GravelyGuy LawnSite Silver Member
    from Indiana
    Posts: 2,517

    Thanks Ric, I also considered adjusting the screws on the controll levers of my Z so that full throttle would be a set speed. On Gravely mowers all that stops the control arms are screws.

    I also just got off of the phone with a Fimco rep. and there is a small check valve that goes in place of the screen. I will check TSC and if they don't have it I will order it direct.
  6. americanlawn

    americanlawn LawnSite Fanatic
    from midwest
    Posts: 5,852

    Ric is right. Also - it looks like the boom could be lowered and larger droplet sized nozzles might be in order? The pics indicates a fine mist at a height I would have concerns about - especially if it's windy. A battery-powered back pack sprayer would be good for the edges. Richway sells inexpensive foam markers, but if you're only spraying broadleaf weed control (no fert), you can probably just go off your tire tracks.
  7. maintenanceguy

    maintenanceguy LawnSite Member
    from NJ
    Posts: 156

    Teejet makes spray nozzles. Go to the Teejet website ( I'm too lazy to look it up but the site has a lot of info on calibrating, choosing spray nozzles, setting spray heights and spacing, how to minimize drift.

    My advice:

    Use no-drip spray nozzle bodies (they have a valve that shuts off completely when pressure drops below 10psi.

    Use a low pressure to keep droplets too large to drift. I like 40psi.

    Know your ground speed.

    Know your nozzel flow rate (see how long it takes to spray 8 oz of water)

    calculate exactly how much active ingredient to use at your groundspeed, nozzle spacing, and flowrate. (the web site tells you how).

    Never never never spray in the wind, even a light breeze will cause drift that you won't know about until you return next week. Then you'll see where it drifted.

    I've been spraying a sunup all week and have had to stop by around 8:00 when the wind picked up.
  8. Ric

    Ric LawnSite Fanatic
    Posts: 11,956


    All good advice.


    Before you ever put anything but straight water in the tank, Take in to the street. Mark off set distances so each mark is 1,000 sq ft. and you travel at least 3,000 Sq ft. If your boom sprays 8 ft wide then 125 ft of travel would be 1,000 sq ft of coverage.

    1st pass on the street should be to check boom height and spray coverage on the street. as the water drys you can see if have streaks of either wet or dry areas. Once you are happy that you are getting even coverage go to the next step.

    2nd pass select a speed and spray at least 3,000 sq ft (more area the better) measuring how much water you use. This can be done off your city water meter by marking you tank and then refilling to that mark. It is important to get the measurement perfect.

    3rd By trail and error find the speed and pressure that gives you the coverage you desire. Even numbers like 1, 1.5 or 2 gallons per thousand help later with mixing math where as 0.82 or 1.18 might make mixing a little more involved. But the math of mixing is simple because you just divided by your gallon per thousand. If you want to apply 1.5 oz of product per K just divide by your gallons per Thousand. 1.5/ 0.82 = 1.83 oz of product per gallon 1.5 / 1.18 = 1.27 oz product per gallon. However measuring those odd amounts might be the problem.

    Boom sprayer can be set up as high tech or low tech as you want and there is a lot more to setting up a boom sprayer than most of us want to do. My first boom sprayer my neighbors teased me that I was trying to grow grass on the street. For days on end I would spray the street until I got it right.

    BTW Large Ag operations will actually use GPS hooked to a computer to do there spraying. The operator only has to look at screen that tells him where to point the Tractor. With hundreds of acres to spray and a air condition cab they want a perfect rate of application. Of course this type of equipment just cost a penny or two more than yours.

    BTW I taught Materials calculation as a student teacher in college. So would like to think I know something about it. I have set up large boom sprayer for other people.
  9. rcreech

    rcreech Sponsor
    Male, from OHIO
    Posts: 6,057

    Setting up a sprayer can be overwhelming when looking a the big pic. As Ric said, just break it down and you will get along just fine. Here are a couple of recommendations from me:

    1) I would recommend using the TEEJET 110 degree AI tips. These are the best flat fan tips in my opinion as you can run higher pressuere (recommeded at 50-80 psi) but with the air induction (AI) it produces a larger droplet hince reducing drift.

    2) Typically you will always want to run the height of your boom the same distance off the ground as your nozzle spacing if possible. Example - If your nozzles are on 20" spacing then you should run 20" off the ground.

    3) Lastly, once you have selected your known speed and pressure, I have found it best to mark a known distance (100 ft) and use a calibration bottle. Once you have driven the 100 ft you look at the bottle and it tells you your gallons/ac. It is very simple and accurate.

  10. Ric

    Ric LawnSite Fanatic
    Posts: 11,956


    In setting up calibration for several different home owners with inexpensive sprayer. I have found it is better to stay with the original Spray nozzles because the are already calibrated to the pump size. Ideally the pump remains on constantly while spraying. To cycle the pump on off, on off cause pressure to vary greatly and wears the pump out too quickly. By trying to change nozzles the average person will not take into account the pump volume. which in turn will effect pressure.

    Selecting Pressure is normally not an opposition unless a regulator is used and they are not included with these units. Therefore I try and work with want is provided using the K.I.S.S. system. To much information can if fact confuse the operator.

    Calibration bottles are nice but can be extra expense and a PITA to find the right size to fit these smaller units.

    I guess my point here is common sense and a good old boy approach can sometimes work and be easier than trying to go high tech.

    My own Boom Sprayers uses a pump larger than is needed and I use a regulator and by pass. Even on smaller sprayer I like the Regulator with 12V Demand pumps because their pressure varies. I also use a remote 12V shut off from Tractor supply for $78.00. I place the shut off as close to the Boom as possible. With this type of set up I can change nozzles and recalibrate fairly simple.

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