Foam Marker FM-40

Accurate & Dependable Foam Markers for Farming and Turf/Golf Applications

Our foam markers are a simple, reliable solution to visually mark the edge of your sprayed area through deposits of foam balls. It’s the most common and economical way to avoid double coverage or lack of coverage during application of chemicals and fertilizers. The John Blue Foam Markers are easy to install and operate. The system creates a highly visible foam line in the field that correctly marks your position. Mixing water with an inert foaming concentrate liquid in a 1.5 to 3 percent solution creates the foam and is both environmentally friendly while economical.

Foam is generated at the end of the boom. This eliminates the foam breaking down in the boom as well as decreasing the waiting period for the foam to travel to the end of the boom. This makes changing sides more efficient.

All John Blue Foam Marker Kits consist of a 12-volt compressor, a solution tank, control box and parts necessary for installation on any type of spraying equipment or whenever precision applications are needed.



  • FM-40 Golf/Turf Marker has 52 ft. of liquid and air tubing (for end of boom discharge).
  • Air tube: 1/4″ diameter.
  • Liquid tube: 1/4″ diameter.
  • 15 ft. of cable to connect the remote switch to the compressor is supplied.
  • 6 ft. of power cable connects remote switch to power supply.


Model Boom Size Tank Size Gal. Refill Time (Max. Hrs.) Refill Time (Min. Hrs.) Max. Output Balls/Min. Min. Output Balls/Min. Foam Sprayer Nozzles
FM-40 Up to 40 ft. 4 2 3 25 18 2 Vertical Switching


Switch Box Kit: Allows foam to be discharged from both ends at the same time.