Concrete Yard (Courtesy of Deere-est)
Smear on the Polyfilla and spread it till it is roughly even and covering all the base. Grab a ruler or similar narrow edged tool, wet it and tamper it in whicheer direction the water should run. Wet the rulers edge every now and again and also keep wiping off any Poly it picks up. Then when you have done this two or three times wait for it to dry. As it becomes more viscous but not yet dried out, use something circular (I used a length of plastruct) wet it and drag through the Poly leaving a trough for drainage. If it goes crooked or something, don't panic. . . .wet the ruler, reetamper it and wait for it to dry slightly then try again.
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