Why would someone pour molten aluminum into a watermelon? I’m sure that the question has probably never come up in conversation with your co-workers, friends or family. Or maybe it has?
Since we now have your attention on the subject … let’s go ahead and just answer the question of what would happen. Fortunately for us, The Backyard Scientist has already done so. We are all spared all the mess, heat, expense and safety concerns associated with this proposition. Let’s just kick back and permit them to do it for us: https://youtu.be/fgnsXPnAX8M