I used irrigation tubing, the small kind you use for a drip system. Today I will cover the tubing with cement soaked cloth so the cement will adhere well to the plastic parts. You can see were I've done this in the pic, it's red cloth. I had to do the spiral part post haste as this little bird kept landing on it and there was a lot of scratchy wire poking up, I was afraid he'd hurt his feet.
