Foam marker plans

Well – I threw together a makeshift prototype and dang if this thing doesn’t work pretty nicely. I used a 12v tire inflator compressor, 1 gal gas tank w/ a valve stem added and a cheap air stone “crammed into” the interior end of the stem. Rigged some 3/4″ vinyl tubing onto fuel spout and then reduced it to 1/2″ w/ a barbed fitting – put a 90 degree ell w/ a 12″ poly pipe in the end to drop the foam closer to the ground. I used the 4 oz of dishsoap in 1 gallon water and it made nice plops (about like shaving cream consistency). The larger design issue is where/how to mount the compressor & tank. Total cost – ~$20 not including the compressor but even with that, I’d say you could do this for under ~$60.

Worked great! Almost. ‘Cept I just spliced the compressor power line (zip cord) into the power line for the sprayer. Worked good for a while then both sprayer and marker would quit operating. When I pulled the 12v cigarette lighter plug out it was super hot – pretty much cooked the switch by running too much current through it (my diagnosis) so the compressor needs to be wired to the battery directly – at least not through the same switch as the sprayer pump. I knew better but impatience got the best of me.