Get on the "piss" as Patrick would say. Why are you troweling dry curb? Does the concrete pull every time u make a pass? Why? Piss is a troweling lubricant along with evaporation control. Mist over the curb before you finish, boom....done. We don't talk about troweling, it's only finishing. One gallon mixed will get you approx 12 gallons of piss. Each gallon will get somewhere between 250-350 feet of curbing.