Howdy, pondering making a grape trellis out of sections of 1/2 by10' copper pipe. wondering on how long of span the pipe would withstand. Cogitating 2 parallel pies and brazing cross pipes every foot. Any ideas?
I'm not sure exactly how long of a span you can utilize with the 1/2" copper but you can increase the structural stability by using 45 degree angles every several feet between the main supports to make a truss. Kinda like buliding a ladder with 45 degree diagonals between main supports. If you need to use single, unsupported pipe, experiment with spanning pipe between two supports and hanging weights of the approximate weight of the grape vines.
I seen something at a Yard/Garden/Craft show like that. From what I remember they stuck dowel rods inside the pipes. They were the same size as the inside of the pipe. They wipes some kind of lubricant on the first 5 or 6" of the dowel them drove it in on a concrete sidewalk...It wasnt very wide, maybe 4.5 ft.
They did have some arched ones also made from coil/rolled copper.I know they were pretty expensive but sweet looking.