Wisdum-
I am currently building a project extremely similar to this, except in my version the 'bomb' is buried underground, IED style. I have rigged a solenoid valve to a compressed air tank, and when activated it sprays washable paint upwards out of a shower head, marking anyone who would have been killed by a real bomb. It would be a great help if I could get a schematic and parts list (preferably with a website or store name where the parts came from)
Thanks
/me