Build Your Own High-Volume Boom Sprayer with a DIY Kit

For farmers and agricultural workers, having an efficient boom sprayer is essential for applying pesticides, herbicides, and fertilizers across large areas. But purchasing a ready-made boom sprayer can be prohibitively expensive for some. A cost-effective alternative is to build your own custom boom sprayer using a do-it-yourself (DIY) kit.

DIY boom kits allow you to convert your existing spot sprayer into a high-volume boom model that can cover significantly more ground in less time.

Planning Your DIY Boom Sprayer

The first step is deciding on the size and specifications for your boom sprayer. Consider factors like:

• The dimensions of the area you need to spray
• The type of crop or terrain
• Your target application rate (gallons or liters per acre)
• Your intended spraying speed
• The spray capacity and power of your existing spot sprayer

This will help you determine the optimal boom width, number of nozzles, nozzle spacing, and other design factors. Generally, wider booms with more nozzles provide faster coverage, while narrower configurations allow greater precision in irregular-shaped fields.

Choosing Your Nozzles

Nozzle selection is also key. Look for nozzles designed specifically for agricultural spraying, labeled with their spray pattern and flow rate (measured in gallons or liters per minute). Consider factors like:

• Spray angle - Determine width of spray pattern
• Droplet size - Smaller droplets are more prone to drift
• Material compatibility - Ensure nozzle suits the spraying medium
• Anti-drip valves - Prevents unwanted discharge/dripping

Flat fan nozzles are common for boom spraying over broad crop rows. Hollow cone nozzles work well for broadcast application. Whatever you choose, having multiple nozzle sizes allows flexibility.

Calculating Nozzle Spacing

To achieve uniform coverage, nozzles must be spaced correctly along the boom. The formula is:

Nozzle spacing = (Boom swath width X 100) / Spray angle

For example, with a 5-foot boom swath and 80deg nozzles, optimal spacing would be:

(5 ft x 100) / 80deg = 75 inches between nozzles

You can then determine the number of nozzles needed based on the length of the boom frame. Closer nozzle spacing provides the most uniform coverage but requires more nozzles.

Assembling the Boom Frame

The boom frame provides structural support for the spray nozzles and plumbing. It's typically constructed from stainless steel or aluminum pipes, tubes, or bars cut to desired lengths.

Cutting and Joining the Pipes

Use a hacksaw to cut your pipes and tubes to the proper lengths. File or sand any rough edges. Join straight sections using corner fittings, tee joints, or gussets. For custom angles, bent pipes or hinged joints allow flexibility.

Mounting the Boom

Mount the boom frame securely to your sprayer using the included hardware. Many kits utilize removable boom stands, allowing you to detach the unit for storage. Consider the optimal height and angles for your purposes. Reinforce joints with brackets or gussets for added stability.

Installing the Nozzles

Once your boom frame is complete, it's time to add the nozzles. Most kits include clamps that allow tool-free mounting along the boom.

Drilling Nozzle Holes

Mark and drill holes for each nozzle at the proper spacing, calculated earlier. Hole diameter should match nozzle size. Use a punch or gasket to prevent leaks. For metal pipes, nozzles can also be welded into place.

Positioning the Nozzles

Attach nozzles using the clamps or brackets as per the manufacturer's instructions. Ensure they are oriented properly to produce the desired spray pattern. Anti-drip valves prevent unwanted discharge.

Making Connections

Use small tubing or reinforced hosing to connect each nozzle to the main feeder line. Secure the connections with hose clamps or couplings. Proper sealants and gaskets prevent twisting and leaks.

Connecting the Plumbing

With the nozzles in place, connect the main feeder hoses that supply spraying medium to the nozzles. Install any filters, valves, or pressure regulators in-line for flow control.

Running the Main Hoses

Measure and cut the primary feeder hoses to extend the length of the boom, allowing connection between all nozzles. Use hose clamps to firmly secure. Avoid low spots where liquid could pool.

Integrating Valves and Filters

Valves mounted along the boom allow sectional shut-off for nozzle maintenance. In-line filters prevent blockages and uneven spray patterns. Use the appropriate fittings to integrate them into the plumbing lines.

Connecting to the Pump

Finally, connect the main boom hoses to the outlet of your spot sprayer's pump via a hose or pipe. Ensure all fittings are properly sealed to prevent leaks under pressure.

Wiring the Electrical System

The electrical components of your DIY sprayer boom will likely include:

• Pump motor
• Control box and switches
• Solenoid valves
• Lights or accessory outlets (optional)

Using Proper Wire Gauges

Select wiring able to handle the amperage draw of the motor and components. Heavier 12 or 14 gauge wire is recommended for most boom sprayer setups.

Making Secure Connections

Crimped connectors and proper splicing techniques prevent voltage drops or shorts in the system. Use wire loom or wraps to protect exposed wiring from abrasion.

Integrating Control Switches

Mount master control switches and individual valve switches in an accessible control box. Properly seal any holes to prevent moisture damage.

Verifying Electrical Operation

Before spraying, test all wired components to ensure proper power connection and function. Check that switches activate the pump and valves correctly.

Calibrating the Completed Sprayer

With assembly complete, calibration is needed to fine-tune sprayer performance and achieve uniform coverage across the boom.

Checking the Nozzle Spray Pattern

Test spray a small area, observing the spray pattern produced by each nozzle. Adjust positioning or angles if the pattern is uneven or distorted.

Setting the Operating Pressure

Adjust the pump pressure regulator to achieve the desired spraying pressure (PSI). Pressure affects spray droplet size and drift potential.

Measuring Nozzle Flow Rate

At proper pressure, measure flow rate (GPM) from each nozzle. Adjust pressure or swap nozzles to equalize output across the boom.

Inspecting Spray Distribution

Spray a test strip and visually analyze the liquid distribution. Adjust nozzles or pressure settings to achieve a uniform application across the spray swath.

Operating and Maintaining Your Boom Sprayer

Once calibrated, your DIY boom sprayer is ready for regular operation. Follow these tips for safe, effective spraying:

• Always wear protective equipment when handling chemicals
• Triple rinse tanks/lines and dispose of rinsate properly
• Maintain optimal boom height for coverage and drift reduction
• Use marker flags to track spray swath edges and prevent overlaps
• Clean and inspect sprayer components regularly
• Store sprayer properly in off-season to prevent corrosion

Periodically inspecting hoses, nozzles, and fittings will allow you to spot potential leaks or blockages and perform repairs before major problems arise. Keep spare parts on hand so nozzles, valves, or fittings can be quickly replaced if needed.

Constructing your own boom sprayer using a DIY kit allows tremendous flexibility compared to factory models. You can customize the boom to your specific terrain and spraying needs. Following the planning, assembly, and calibration steps outlined above will ensure your homemade unit is optimized for peak efficiency.

The benefits of a properly setup boom include expanded coverage, reduced spraying time, and cost savings. If your needs change down the road, you can alter nozzle types, sizes, and spacing to adapt your sprayer. Installing a DIY boom kit is a simple, affordable way to start covering more ground more efficiently.