Calculations, i want to dbl check my #'s

Discussion in 'Pesticide & Herbicide Application' started by bcomstock15, Jul 5, 2011.

  1. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,794

    On second thought, I tried again and found that at 1.25 mph and 11.6 feet wide you are covering 1276 sq feet per minute. (or 118.5 sq meters). And you would be applying 1.5 ounces per 1000 sqft. At 2.5 mph you would be applying .75 ounce per thousand sqft. At 3.5 mph you are applying .64 ounces per thousand sqft.
    I agree; your solution is too weak. You need about 58 ml per liter, (at 4 km/hr).
  2. GrandMaster

    GrandMaster LawnSite Member
    from Utah
    Messages: 217

    64ml per liter.
  3. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    wow, 64ml/L i'm surprized its so high. i'll go test it on my lawn :) ok to apply on 25-28 degree celcius days? how much of this product would it take to harm a lawn? its my mail concern obviously. thank you all for your help.
  4. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,794

    If 28 is 82.4 degrees F, you are fine. Coolest conditions of anyone here.
    If applied evenly, you should have a margin of safety. Injury to the grass would occur at somewhere near 2 to 4 times proper rate of application. My opinion.
    Remember if you apply half speed--you will double the rate. Don't forget to stop the sprayer before you stop moving.
  5. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    Heres my spray rig, first one (used only backpack before). That is a 17 HP JD WB GS75 . I removed the deck to take some weight out (easy). What issues to you see me having with it? :canadaflag:


  6. DavidNJ

    DavidNJ LawnSite Senior Member
    Messages: 519

    The nozzles look like they are spraying the front wheels and maybe part of the frame.

    I like the way you reversed the boom so it bends when hitting an obstacle, although that prevents them from fully folding.

    On mine, I have the tank mounted on the arms to the front casters and the boom stretched out in front of them. Leaving the boom to fold forward, I have a problem if I hit an obstacle that you have cleverly avoided.


    You also took a better picture than me! :(
  7. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    pics just taken on my blackberry, decent camera.

    the boom was spraying on the wheels when moving forward, the boom is now a bit ahead. no problems. its nice haveing it fold the right direction, i know someone would have hit a tree or something and fkd the boom up otherwise. it folds nicely, installed a stop to the right boom wont rest on the muffler. i also installed valves to i can run it with the boom folded, for narrower areas.

    When that things full, you definitely notice it. i was still climbing some decent hills, but you lose some traction when your turning and stuff, the wheel thats stopping just drags, i just lean on the handle bar and that seemed to help a lot. if we have a big open field we'll run it full, lots of turns just half or so.
  8. White Gardens

    White Gardens LawnSite Fanatic
    Messages: 6,776

    Bcomstock15, do you have a wide open area where you can do some strait water runs to check your liquid output at certain speeds?

    I'm lucky enough to have a couple of acres to do testing on and I've marked out a 10k sq/f area to see exactly how much output I'm getting at certain speeds and also at different line pressures after doing the calculations.

    At least on some of your bigger properties you can pinpoint it by how many gallons you used over the total square feet of the property you sprayed.

  9. bcomstock15

    bcomstock15 LawnSite Member
    Messages: 42

    White Gardens: yes, i do. good idea.

    I have one more question, on my sprayer (pic above) i wanted to be able to run it with the boom folded for use in tight areas, so put a valve before the nozzles on each outer piece of the boom, Works great.

    The question is if i need to adjust rates to run it like that? the pressure obviously changes, so if i run it at the same pressure as i do with the boom un-folded, does the app rate need to change too?
  10. RigglePLC

    RigglePLC LawnSite Fanatic
    Messages: 13,794

    Are you using a pressure regulator? Check the output per minute with the valves open and closed. If you have a pressure regulator and pressure guage. Experiment, adjust regulator until you get the proper flow. Make a chart and glue it to the tank. " Use 40 pounds except when spraying the center only--then use 30 pounds." Or as needed.

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