Richard and Jonny turn graffiti artists to test the properties of anti-graffiti paint. Then it’s off to the Humber Bridge for a spot of painting – little do they know it takes three years to paint the railings alone. Then it’s off to meet Keith, the man whose job it is to watch paint dry…literally! While Richard finds out all there is to know about a 1950s invention - car airbags, Jonny cuts open a pair of trainers. Then it’s off to a domestic fire alarm testing center to see how chip pan fires, petrol arson attacks and sofa fires are simulated to save lives. Finally, we head to an acoustic guitar workshop to see how nine different types of wood become a musical instrument.