Calibrating a Rotary Spreader

• 1). Lay down a plastic sheet or tarp. The sheet should be at least 10' x 10', but can be bigger.
  
  
• 2). Mark a 10' x 10' area, or use the sheet itself if it is 10' x 10'.
  
  
• 3). Estimate which setting will give you the application you want and set the spreader to that setting. If the material you are spreading is coarse and grainy, set the spreader as wide as it will go. You don't have to worry about getting it exact because you can adjust it later.
  
  
• 4). With the rotary spreader, walk back and forth over the sheet just like you would over your lawn.
  
  
• 5). Weigh a plastic container on a scale, and either remember or write down its weight.
  
  
• 6). Gather the material you spread over the tarp and place it in the plastic container. Weigh both of them, and subtract the weight of the container to find the weight of the spread material.
  
  
• 7). Find the conversion factor for 1,000 sq. feet. To do this, divide 1,000 square feet by the square footage of your test area. Using a test area of 10' x 10', the square footage would be 100 square feet. 1,000 divided by 100 equals 10, so our conversion factor is 10.
  
  
• 8). Multiply the weight of the material that was spread over the sheet by the conversion factor. This will tell you how much material is spread per 1,000 square feet.
  
  For example, if you spread 1.5 lbs of material over the tarp, then you would multiple 1.5 by 10, which equals 15 pounds of material per 1,000 square feet.
  
  
• 9). Adjust the spreader based on your results. If you want to apply more material per 1,000 square feet, you will need to open the spreader a bit more. If you want to apply less, you will need to close it.
  
  

Using a Rotary Spreader

• 1). Now that you've calibrated the spreader, fill it with the material you want to spread.
  
  
• 2). Start by walking along the perimeter of the area you want to spread over. You should open the spreader's drop door while walking.
  
  
• 3). After completing a full circuit around the area, you will want to walk up and down the area. Make sure to leave a little overlap to avoid missing any spots.