When I smoke sausages my casings get tough. I have used LEM casing and The Sausage Make casing all with the same problem. The LEM casings were packaged in salt and the Sausage Maker casings were packed in a brine (I buy a Hank at a time). I use 20-22mm for breakfast and snack sticks and 32-35 mm for Italian, Hot Links etc. When I make fresh sausage the casing are tender but when I smoke sausage they get tough. I prepare my casings with a complete rinse in cold water inside & out. I then soak my casing in cold water with a little bit of white vinegar. I soak them for 2 hours and I change the water at a minimum of 3 times to make them soft and pliable. When I stuff the casings to make smoke sausage I place them in the refrigerator overnight to let the spices and cure get happy. The sausages are in a pan covered with plastic wrap to prevent drying. An hour before going into my 40" MES I take them out of the refrigerator to air dry a little. They are then placed in my MES at a temp of 130 (no smoke vent wide open) for an hour to dry out. An hour later I start adding smoke and leave the temp at 130 for and additional hour. I then bump the temp to 140 for an hour and then I gradually bump the temp to 165 until the internal temp of the sausage is 160. Do I need to use a water pan or am I missing a step in the smoking process. Any help would be greatly appreciated. Thanks in advance.