The seven remaining woodworkers face the toughest big build of the competition so far and one of the hardest objects to make - a chair. They must bend and build their way to create chairs that could become design classics in just two days and craft what would take a professional weeks to make. And in the skills challenge, the woodworkers' whittling skills are tested. Award-winning architect Alex de Rijke and queen of furniture-making Helen Welch monitor proceedings as judges, with a double elimination in the offing.