Rebar splicer - GIF

[IAMSatisfied]

I'd like to see the end product of that process & wonder what the granules are that he's using.

That wouldn't pass code here in the states... welding on rebar is pretty much verboten as it changes the structural characteristics of the rebar too unpredictably. Lower grade rebar seems to already be plagued by huge variations in composition. I was once bending some #5 rebar (sourced out of Northern Mexico) in a manual bender, putting all of my weight into it, when the rebar snapped before reaching a 90º bend, landing me flat on my back... the break revealed a crystalline structure much like cast iron. I never had much enthusiasm bending heavier rebar after that experience.