I like your videos a lot doubleboost. They're real. And it's nice to see someone else working in a small shop, and using scrap -- I can identify with that.
I have the same type of metal, on hand, too. Here it's called Uni-strut I think. Used for pipe and cable hangers with all-thread. Like you I try to avoid welding galvanized. I always weld and cut outdoors, but perhaps you have neighbors closer than I do. Even outdoors you still get the fumes from galvanizing unless the wind is strong..
It's very important not to weld or cut with a torch cadmium plated hardware or chrome plated -- zinc in galvanizing is not pleasant or healthful, but those others are quite dangerous. Sometimes older painted metal has an undercoat of red lead, too. These are some of the things to be aware of when using scrap materials. Cadmium plate looks slightly gold or multicolored. Often aircraft bolts and hardware is cadmium plated.
I particularly liked your video on core making -- I've done it myself, but learned something new from your own way of doing it.
Never heard of a log crocodile. Will have to look for your next video!