I used cold-rolled steel to frame steps/platforms in my front yard. I also used the chemical solution to remove the black carbon so that it would have this rust effect--which was so much messy and hard work that cor-ten would have been much more worth it. I then painted the back side with rust-preventing paint, patinaed the front so it would rust immediately, then applied a 2-part clear coat to protect it. Without the protection, the metal would fail in 3-5 years (and it was heavier gauge than this). I'm hoping my treatments will last at least 10 years. But it didn't end up looking this good This rust looks beautiful, but soon it will start to rust badly and flake in layers. Cor-ten is much more expensive, but after the work it takes to get steel to look like this and be protected, its worth it. (unless you're looking for a 3 year solution). I've never seen metal like this at a building store, look for a local "metal supply" or "metal fabricator." For metal patinaing solutions check out sculptnouveau.com

It appears that you used 12 inch strips cut from a 4X8 sheet of 16 guage steel (I plan to dothe same). How did you join the strips together? It appears that there is some sort of clip, or are these simply strips of the same steel cut in 3or 4" wide strips 18" long so that they can be anchored in the ground to support the curves?

Wow Wobbly. you worked very hard on your project! We didnt think it though to that extent. The bed has been in for about 5 years and is showing no signs of failure. Our beds are joined by overlapping steel ends & though bolting. The curves are supported by the soil and the curves themselves. And just sitting on the ground. All in all pretty low tech.

Olivine Land -Great look. Im in Portland also, but it appears this job was at the coast? Can you explain your treatment process and what checmical you used to removed the galvanizing, and what you used to give the rusted look?

I would never use a structure like this despite its beauty, because clients need long term solutions. Stone is best but prohibitively expensive. Am working on a solution...not immediately helpful but, serious.