You can't hammer tin into iron, no matter how hard you beat it, but that doesn't mean it's useless.
George R. R. Martin (2012). “George R. R. Martin's A Game of Thrones 5-Book Boxed Set (Song of Ice and Fire Series): A Game of Thrones, A Clash of Kings, A Storm of Swords, A Feast for Crows, and and A Dance with Dragons”, p.381, Bantam
