I mentioned that I had used a similar product. That was before I viewed the video. This stuff is much different..obviously more of a solder than anything else, but very cool looking.
Just watching the bright silver flow makes me want to buy some and try it. It sure looks like it makes a strong joint as witnessed by the 'T joint' hammer attack.
I am guessing the secret is the heat, and the fact that the parent material isn't melted. The stickler with gas welding aluminum is that you have no real clue that it's about to go molten on you. It's there one second, and boom, gone the next.
The process I used involved cleaning the oxide off the item, then dusting it with a sooty acetylene flame. The soot coating allowed you to see the aluminum turn molten, but didn't interfere with the weld itself. Fun stuff.
Stuart