It's not very tall, but I turned a large tomato cage upside down, anchored it with pins made from the metal rods used in soldering, and attached a wooden finial on top by pulling the 3 ends together. All of these items were purchased at the same big box store for a small amount of $$. I wish they had even taller tomato cages, because the results aren't bad looking but it is a bit short at 4 ft tall.

Transplanted, that's almost exactly how we made obelisk shaped frames for several pots- except we curled the ends that used to go in the ground and since dh is a welder, he welded them onto a frame that would poke into the pots for stability. They have held up for 5+ years of vigorous growth. We have made several copper trellises in our garden, and it's not difficult. You can figure out a pattern yourself- i'd think and obelisk would be fairly simple if you didn't want crosspieces. You can use joints to join stuff at angles or bend the metal. If you do joints you have a choice to soldering it to make it stronger (if there's going to be anything growing on it making weight, i'd recommend that). If you wanted crosspieces, you'd need a lot of joints that would get fairly expensive. For the top join, i'd probably pound the ends flat together and run a bolt through them to secure it (not pretty, but functional). I don't think a joint will work there- too narrow of an angle. I guess if you were really good at soldering you could cut the pipe at an angle- which would be hard- and then solder them together, mitered style. You could also top it off with a little copper sheeting or a wooden top, instead. To anchor it in the ground, i'd pound metal slightly smaller than you copper a good 18" and the correct angle and just slip the obelisk over top. Or you could make the bottom be a square with pipe & joints and that way it could be movable- but beware, it could also topple.

I've been wondering how to use copper piping because I like the look of copper. Your description has given me some good ideas on how to make it work. Thanks, Tam

Copper is fun to work with, and is gorgeous when you're done. I like using the refrigerator stuff to get neat coils for non linear projects. Just pay attention to which type you're buying- if you plan to bend it in gentle curves you need the less rigid, straight kind. If you want straight, true lines, get the harder stuff. Also, buy a pipe cutter- it's a cheap little gizmo you clamp onto the pipe and incrementally tighten as you twirl it around. Easy way to get a nice clean cut. You just have to be sure you get it on straight to begin with or it'll spiral. If you want really smooth bends you can spend some dough getting a pipe bender thingie, but if you look around you may be able to find something around to bend it against- just go slow & easy or it kinks (i often use use my feet against the ground). You get a feel for it fairly fast. You can also do trellises and stuff out of the galv pipe- which is cheaper. That you don't solder (well, maybe you can); you weld it to keep it together. I haven't tried to solder it since hub's a welder.

Might be fun to weld old refrigerator (icemaker water supply) copper coils to a galvanized pipe to make a funky tree form that many kinds of vines could cling to.
What kind of spray would you use to keep the bright copper appearance since it turns so fast in this climate?

not sure- maybe shellac or poly would keep it bright. Worth a shot. I'd think anything that sticks to the copper and is airtight would work. I like the way copper patinas, so i was never interested in keeping it bright. On its own it patinas over a year or 3 to a brown, then eventually to the lovely blue green. If you want to escalate that process, fumes of certain acids will help. You also use acid (lemon, vinegar) to clean copper, so i'm not sure where the fine line is.

That magazine.. Backyard Ideas, I think it is, has plans for an obelisk shaped trellis made of wood and copper tubing. Looks fairly straight forward and gorgeous too. Most of my plants that are getting staked/trellised this year I've done but thinking of doing this for next year.