I have searched the web and went through the suggested liner posts and could not find anything related to my issue. What are the ramifications to having a flexible stainless steel 6” liner inside of an existing 8” rigid chimney liner? We pulled the 6” liner trying to find out why the previous owner had done this and after running a camera through the 8” rigid liner we found separated sections. My stove only requires a 6” liner my other question is should I insulate the 6” liner? I have a wood burning lopi stove republic 1750.