He originally built the metal claws quite a few years ago while doing an internship at a local machine shop, in Toronto. Basing them off of the movie X-Men Origins: Wolverine (2009), the claws measure 33CM (13”) and are made of high carbon steel, nickel plated for a mirror finish.
They took about 20 hours to make. The outline was waterjet cut, the blade details were machined on a CNC, it was hand ground to shape, and then TIG welded together. The entire assembly was then nickel plated to create a mirror finish. You can see the process below.
With Logan releasing, he apparently decided to go HAM, and added electricity, giving them a sparking effect.
How’d he do it? A car battery was connected to the claws, positive on one claw, negative on the other. When connecting the claws together, the car battery is short-circuited, resulting in big ass sparks. These sparks can draw anywhere from 200-300A, which the car battery can safely provide, rated for over 1000A cranking (if this sounds like jargon, you can learn about it here).
The sparks are actually tiny bits of superheated metal coming from the claws – so the effect does slightly damage the metal of the claws. Basically, the claws are acting like a resistor – becoming red hot, melting, and shooting little bits of molten metal away at high-speed for a glorious effect. These puppies even get hot enough to even melt through certain materials, like chicken wire, aluminum foil, and steel wool.