When I got this sword, it was completely covered in blood rust. Sword maker Francis Boyd is showing me yet another weapon pulled from yet another safe in the heavily fortified workshop behind his northern California home.
You can tell it’s blood, he says matter-of-factly,
because ordinary rust turns the grinding water brown. If it’s blood rust it bleeds, it looks like blood in the water. Even 2,000 years old, it bleeds. And it smells like a steak cooking, like cooked meat. I’ve encountered this before with Japanese swords from World War II. If there’s blood on the sword and you start polishing it, the sword bleeds. It comes with the territory.
Blood rust: I hadn’t thought of that. I guess it would turn water red, but the steak comment is kind of creeping me out, as is the growing realization that if these swords could talk, I couldn’t stomach half the tales they’d have to tell — via Collectors Weekly