Keep Heat Low

• Start the fire about 30 minutes before you plan on starting the ham. The charcoal should burn low so the heat is low to medium. Test the temperature with an oven thermometer -- it should read 325 degrees Fahrenheit -- or place your hand 5 inches above the grill grate. If you can hold it there for 5 seconds the fire is medium so the ham is good to go. Use a roasting pan to hold the ham. Keeping the grill cover shut traps the heat and turns the grill into an oven.

Wrap It Up

• Wrapping the ham tightly in aluminum foil keeps the ham moist while it heats up. Brush the ham with juice, letting the liquid dribble down between the slices. Pay careful attention to brush the tops and sides of the slices since these have a tendency to dry out first. Use two sheets of foil, one lengthwise and one across the width.

Give the Ham a Bath

• Instead of placing the ham on the grate directly over the coals, move the coals to both sides and put a pan of water in the middle, underneath where you'll put the ham. As the water steams it keeps the spiral ham slices moist. Instead of water, try apple or pineapple juice. Toss in some herbs to flavor the steam as well. Another way to do this is to put a cooking rack in the bottom of the roasting pan. Fill the pan with water until it reaches the bottom of the rack. The ham should be sitting above the water, not in it.

Basted and Glazed

• Basting keeps the slices from drying out. Wine, fruit juice and beer all work. If you're making gravy with the pan drippings, choose a liquid that adds the flavor you want to the gravy. Glaze the ham during the last 15 minutes with your favorite ham glaze, or try honey mustard diluted with orange juice; apricot jelly diluted with apple juice; or a spicy glaze of lime juice, brown sugar and cayenne pepper. Spiral hams should heat for about 9 to 18 minutes per pound and reach an internal temperature of 145 F. For example, a 5-pound ham would take 45 minutes -- 9 minutes times 5 pounds -- while a 9-pound ham could take up to 2 hours and 40 minutes -- 18 minutes times 9 pounds.