Symbolism, Imagery, Allegory
What is wood? It's earthy, organic, and importantly for Will, malleable. For a boy who's drawn to the water (be sure to read up on this elsewhere in this section), wood brings him back to land, it grounds him.
Will is stuck in woodshop and claims he's not that into it. Okay, fine. But the thing is, he's making statues and such at rapid speed and can't seem to get enough. He's so lost in creating these wooden statues, in fact, that he loses track of time, which turns out to be very therapeutic. For a guy who needs to get out of his thoughts, which are mostly dragging him down, woodworking is just the kind of hands-on, brain-quieting thing he needs in order to get caught up in something else—in this case, the creative process. Like we said, wood grounds him.
Will's foray into wood also shows him what he's capable of. We're not trying to sound like Mr. Jacks suggesting that Will's purpose on earth is to make more gnomes—that is, unless Will wants to. Instead, our point is that Will's creations bring him closer to seeing and understanding the parts of himself that get buried under all his negative self-talk. He's so down on himself all the time, but his skill with wood is pretty much undeniable. He may not like it, but it's just true that he's good with wood—which means he's good at something in general.
Wood, then, is a sort of antidote for Will. It isn't necessarily what cures him—that's arguably water—but for a kid who's not so sure of his place on this earth, wood certainly seems like it helps keep him alive.