There is no such thing as a sucking chest wound. All chest wounds suck. Except perhaps for fake ones, which are essential to making a really gritty, gory film in most cases. This video features detailed instructions on how to make a fake chest wound out of latex and other special effects materials. Since it is a prosthesis, it can even be reused! It is a little complicated, but the end result looks great, so try this out in your next movie!