Here is how we are putting together the columns.
We went to our local carpet store and got "for free" empty cardboard carpet rolls, these look like large paper towel rolls. They come in 12 foot long rolls. We cut them to the size that we wanted, ranging from 4' to 8' tall.
We built bases out of 1" thick plywood, and 2X4's. The 2X4 is attached to the plywood and goes into the hole of the tube (for stability). We then coated the tubes and bases with joint compound (normally used for patching holes in walls or filling cracks). After the compound is dry, we lightly sanded the compound just enough to give it a rough look.
After that, we spray painted the columns with Stone Touch spray paint made by Plasti-kote.
The joint compound was purchased for $28.00 for a 42 pound bucket, the spray paint was around $8.00 a can, and all were purchased at Wal-mart. The wood we used was all scrap that we had around the house. If anyone wants step by step pictures we can provide them.
teamse@hotmail.com