Robots and Found Objects

I've been welding on Thursday nights for a while now, since I took a welding class several months ago. So far it's all been practice welds of random steel scraps. I've been thinking about trying my hand at something a bit more artistic. Sculpture from found objects has always interested me. Robots have always interested me. Why not combined all this into something like a robot sculpture from found objects? It's been done before by artists like Gordon Bennett and Clayton Bailey.

The first challenge I'm facing is figuring out how one goes about finding these so-called found objects that artists are always talking about. In my case, I'm particularly interested in steel objects. Susan and I have been going to estate sales on the weekends and I've visited numerous thrift shops around town. It seems like the best source would be something like a wrecking yard. There are plenty of them around but very little info about them online. Apparently not all of them let you wander around with tools pulling interesting parts you find. Maybe there are some in the smaller towns surround the Dallas area. I'm surprise there aren't any web sites that review wrecking yards (at least that I've found yet).