Hi,
Yesterday was the first time I tried this putty, and I'm not sure if I'm doing everything right. It's "crumbling" instead of spreading on the plastic surface. I was expecting a paste, and it behaves like it was dried-out. I've seen people using it for many fine works (hair for figures, etc), so I know it works, but I don't know how

The instructions are vague at best on the tube.
Thank you.