I have been using my new smoker since the first of the year with pretty good results,but one problem seems to continue and that is a lot of my wood chunks and even some chips don't turn to ash.I do soak them for a couple of hours and use all different types of wood.Now I must say that I'm using the thin chip boxes that come with my Smoke Hollow Gasser 24" unit.I have read that some folks replace these with cast iron boxes.What do you guys think?.I have plenty of heat,with both burners on low it's at about 230-250.Thanks in advance Mike