I don't glaze mine until it's within an hour or two of being done , and I don't use foil , it keeps the smoke from reaching the meat well . Most smokers have a bowl to hold water for wet smoking , this keeps the meat from drying out but you have to make sure that the bowl doesn't dry out before the meat is done . Refill the bowl with near boiling water as needed . You can also inject the meat with marinade to prevent drying , and add yummy flavor at the same time . I like a blend of Tony Chachere's Creole Butter and some pumpkin pie spice and pineapple juice for holiday hams , I always get good review with ths marinade . For glaze I like to use chinese hoisin sauce or duck sauce .

My fave for smoking hams is applewood chips or pellets , I wrap them in foil to make several "chubs" which I add as needed to keep a constant smoke going . If you're using chips soak them for 1/2 hour , then wrap in foil with just a small hole in it to promote smoldering . It sounds like you're using a charcoal smoker , just throw a chub of chips right into the bowl of coals as needed to acheive the level of smoke flavor you want . The ham will be done when it reaches an internal temp of around 160-180 , consult your owner's manual for the temperature and cooking time for the weight of the ham that you're making . It will almost certainly require adding new coals to acheive the proper cooking time , be sure to keep an eye on the temperature and time to determine when to add the new charcoal .