I need to make an inside cut on a piece of Formica that is 5x12'. The only surface I have large enough is the garage floor. I have a 4x8' sheet of sacrificial plywood that the Formica can be cut on. I have an 8' straight edge made of aluminum and it is pretty stiff. One problem is I have to hold it by hand as I cannot figure out how to clamp it. Now what to cut with... I can't use my trim router. Can a utility knife cut through this stuff? A couple years ago I tried a pair of air plane snips - NOT! any suggestions will be appreciated.