Building a 12V Herbacide Sprayer

[alldodge]

Instead of buying one, I'm looking into building a herbicide sprayer. Have a 250 gallon square tank on a pallet. So need a pump, tubing, bypass valve, wand, tubing and other stuff.

Want to put the tank on the Kubota RTV and then have tubing to make a boom to spread out maybe 20 to 30 feet. Then have another line to feed a hand wand.

Anyone ever build something like this?

 

[Scott Danforth]

I didnt build it, however used the neighbors often.

Was a 25 gallon tank on a harbor freight trailer. The pump was from a farm supply store. So was the PVC t-bar tube (3/4" pvc) with 6 ag spray tips. They were on 12" centers. 2 c-clamps with a bolt welded to them held the spray bar to the front of his zero- turn. Used p-clamps to hold bar to clamps.

I prefered to put the bar at back of trailer, that way i could cut and spray vs cut then spray

Aligator clamps to connect to the tractor battery

Sprayed about an acre, then refill

 

[alldodge]

Will look into the 6ag spray tips.
How far above the ground was the tips, and what pressure?
Did you use a bypass valve to return overpressure?
Most the pumps I'm looking at I'm seeing 60psi

I have around 10 acres I need to kill briers, and some areas are pretty steep. Bush hogged the area a month or so back, and the briars are looking real green and coming back. Plan to spray them with crossbow, then when there dying, and wilted, want to come back and spread new grass seed.

 

[Scott Danforth]

Spray bar was about 12" above ground, angled to spray about 45 degrees. Covered abou 6" wide

No bypass, nothing. Inlet of pump to bottom of tank, outlet to spray bar.

Motor was abou 3" in diameter and about 5" long. Maybe 1/6 hp, maybe 1/3.

If i had to guess, about 30-40 psi based on the spray force

 

[mla2ofus]

Alldodge, you're looking at 1,000 lb of water plus the weight of everything else and going across a hillside it might get the pucker factor pretty high. Might be better built on a very low tlr with a wide axle.
Mike

 

[alldodge]

I hear ya Mike, have thought of that. Don't plan to fill it up, to start maybe no more then 50 gallons to see how it works, increase if it works out. Its an IBC type tank and if need be will put on a trailer. Wouldn't mind having a PTO but that is even more money. Guess I could make something up to install on the 3 point hitch and run off the battery

 

[mla2ofus]

Guess my mental math is slipping, it would be 2k lbs of water. The metal frame will be good to hang the booms on. I built one several yrs ago and sold it before moving. With a riding mower engine powering a roller pump with an adjustable pressure relief valve. In my research I found pressure is not critical as too much pressure creates a fine mist that drifts too easily. On centers placement of tips is critical to prevent too much overlap and ground speed is very important to getting proper per sq ft coverage. Took a lot of calculation such as individual tip output at "x" psi x number of tips. I had mine on a skid in my little Mazda pickup and found ground speed by timing # of seconds to cover 100 ft idling in first gear and adjusted pressure to match that for desired sq ft coverage without too much misting.
HTH,
Mike

 

[jakedaawg]

Do you need to pump the fluid or could you mare easily pressurize the tank. A compressed air tank and a variable pressure regulator? I know nothing of such set ups. Just spit balling...

 

[alldodge]

I like the idea, but from what I'm reading, could use around 30 psi to spray. That much pressure on the tank would rip it open

 

[Scott Danforth]

With enough pressure, the explosion could cover your 10 acres

 

[jakedaawg]

Like I said, was just spit balling. Good thing smarter folks than I are around. I was thinking of my little hand held pump sprayer. Had no idea it would take that much pressure.