Bill, Sono tube is just a heavy gauge cardboard tube. You can get them in 8, 10, and 12 inch diameters. I think they come standard four feet long.
I bored the holes for the footers with a power auger, then set up a couple of boards to either side of the holes and tacked the sono tube to the boards, just to lightly hold them in place. Then mixed the cement and dumped it in. Sorry, first I dumped some gravel in the bottom of the holes and tamped it down a bit. I filled the tubes to the top and trowled them off level. Then sunk a J bolt which is just a long galvanized bolt with a 90 degree bend at the unthreaded end. The cement should be stiff enough to hold the bolt in place, but on one of my posts I must have mixed it a bit wet, so I drilled a hole in a board, laid that across the tube with the bolt passing through the hole, and loosely put a nut on the end of the bolt. This was just to keep the bolt vertical while the cement set up. But if you mix the cement properly, it shouldn't be that wet and the bolt should stay right where you place it. -- Blue skies. Dan Rossi Carnegie Mellon University. E-Mail: d...@andrew.cmu.edu Tel: (412) 268-9081