Please Help With Gardening Project

My husband and I started a garden in our backyard. Because plots of land tend to be quite small here, we are trying to make the most of our space by growing what we can on trellises (e.g., cucumbers, tomatoes, peas, Malabar spinach). In the picture, you can see that we used 4 old, rusted legs of a shelving unit -- the shelves rusted away, but the legs were still solid enough to use to build this trellis.
We are hoping some of you have old materials lying around that we can use to construct more trellises. Metal (36 inches or longer) tends to work best. Wood does not work very well because it rots too fast in Okinawa's harsh weather conditions. If you have anything that you think might work, please let us know what it is and when/where we can pick it up. If you are unsure how to describe it, please just send us a picture by selecting the "Picture" button in green, below this conversation area. Thank you!