I've heard that same thing about wrought iron. Every time I see an old iron structure I wonder, is it -- or isn't it? While I'd think, that with the general unavailability of the material somebody would have staked out any structures that are wrought iron. Maybe not all of them though.

True wrought iron was made in the US as late as about 1950, so there is a bunch of it out there in various places. Old wagon rims, bridge parts, building beams, etc, made before the first World War will most likely be wrought.

Wrought is easy enough to spot if you cut it part way through and then break it - the break will show as fibrous in nature if true wrought.

Wrought came in several grades, from muck bar at the bottom to triple refined at the high end. The difference being how many times the bar was forged and/or forge welded to tighten the grain and make it more homogeneous. For work where you'll be etching to show the grain, the regular merchant bar is about right. The triple refined won't show bold enough striations when etched.

When you forge wrought iron, keep it very hot! If you try to work it below a bright orange heat it will very likely separate. Wrought iron takes much higher heat to "burn" than mild steel, so you'll be fine working it at a high yellow to almost white heat. If it starts to "spark" you're too hot.

Have fun with it! It's a joy to forge weld, by the way.

Rich