Casting in foam?

I'm making monster-sized claws for the fursuit I'm working on. Imagine a saber tooth, but over a foot long. I'm also making claws for the feet, basically a sculpted claw 'cap' that goes over a shoe, like the hooves some people have made.


My question is for people who have worked with flexible foam - how plausible would it be to cast these claws in foam? Will it be too heavy for foot-long claws, about three claws per hand? I have absolutely no problem sacrificing comfort for character integrity, but there's a limit, haha.

Can I be a bit cheap with molds and use only plaster? I'm literally just making 6 claws and two foot caps - no need to save these molds or the original sculpts. Any advice here is much appreciated, as I've only cast with urethane resin and I'd strongly prefer not to use that.

If you think foam is a good material for these claws, what kind should I buy? I have checked Smooth-On's website and they offer so many types, I'm not sure what to go for. It needs to hold up over time, even though I won't be wearing the costume that heavily. I'm also totally fine with going with another company.

I just have no experience with this material and figured I would see if any experts could weigh in. Thank you in advance!