THIS GRISWOLD NO 53 SQUARE EGG SKILLET WAS TAKEN DOWN TO THE BARE METAL WITH SILICA BEADS IT WAS THEN WITH WARM MINERAL OIL.UNTIL NO MORE RESIDUE  WAS SEEN IT WAS THEN SEASONED WITH HOT MELTED LARD WHICH GOES INTO THE CLEANED PORES. IT IS THEN SEASONED AT 525 DEGREES FOR ONE HOUR THEN TURNED OFF AND ALLOWED TO COOL DOWN SLOWLY FOR ONE HOUR THIS GIVES A HARDENED QUALITY TO THE CAST IRON.