Silk is going to take a beating during the felting process. It gets very weak when it's wet and has a tendency to break if wet *and* stressed (agitated). It's also likely to lose its color.
You will probably get a very interesting texture.
Unless you know a lot of people with different head sizes you could give the finished hat to. you should sacrifice some yarn for a swatch and felt that, then decide how big to knit the hat.
You will probably get a very interesting texture.
Unless you know a lot of people with different head sizes you could give the finished hat to. you should sacrifice some yarn for a swatch and felt that, then decide how big to knit the hat.