Got my liner kit today and realized that I'm going to need an elbow. In searching for an answer to whether I can use a black elbow or not I came across several threads staing that will last a year. Why is that? If one has a block off plate and fully insulated liner how does so much condensation form that close to the stove to ruin a black pipe? Now I don't know what I'm going to do if I cant find a SS liner.