Sorry to all the naysayers, but explosive bonding is indeed how the start of copperclad voins started with quarters and indeed explosive bonding process was used and I was personally involved with this process. (yes, I'm that old). I was 18 and basically a swamper. But it was the most amazing thing I saw. It was done in a cave like structure away from population. I didnt see the documentary you guys are talking about, but its as factual as you reading this. RH