Since I was making 2 of these and they’re symmetrical, I decided to sculpt one half of the blade. This would be molded and cast 4 times in resin, then the resin halves assembled to make 2 complete knives. I started out by cutting the rough shape from illustration board.
Since the casting resin isn’t terribly rigid on its own, I carved recessed out of the blade and hilt to hold a 3/8″ steel rod to act as the core. These were glued in with gorilla glue, which expands as it dries and will ensure a tight fit.
I originally finished these in a “clean” look, but discussed with my client the option of weathering them to make them appear more realistic. After a bit of hesitation, but it was eventually decided to go ahead with the realistic treatment: