Can I weld?
Don't know. But that appears to be what's going on. And the angle iron is all attached around the trailer, ready for sill plates!
Attached: liquefying metal, the white hot seam barely stirred, electrifying tools if you're not careful, omnipowerful, and confusing to the muscles because they couldn't smush metal together, yet (with their doing?) right in front of the body, metal was just squished in a deciding come-together even if 1/4" out of place. White hot. Hindsight rocks.