In a large saucepan, combine the salt and sugar with 2 quarts of the water. Bring to a boil over moderately high heat, stirring to dissolve the salt and sugar. Pour the brine into a very large pot. Stir in the peppercorns, chiles and cloves. Add the remaining 4 quarts of water and the ice and stir until the ice has melted and the brine is at room temperature. Add the ham, skin side up; the skin does not have to be submerged. Brine the ham in the refrigerator for 24 hours.