AT THE JACOB JAVITS CENTER IN NYC, THERE WERE 2" THICK MOMENT PLATES BEVELED FOR 100% PENETRATION AND THE FABRICATOR SENT OUT 3/16TH. IN. BACKING STRIPS. THE FLUXCORED, GAS SHIELDED WELDING WIRE WAS BLOWING THROUGH THE BACK-UP BAR. NEEDLESS TO SAY, I WAS AMAZED AT THE PENETRATION. THE AMOUNT OF WIRE LAYED DOWN IN AN 8 HOUR TRICK WAS AWESOME. IT WAS ALMOST LIKE A CASTING PROCESS INSTEAD OF WELDING