i have a fisher insert that i installed on a well built hearth. my chimney consist of 6' single wall and 12' of double wall class a chimney. the problem i have is when i get a fire going good the flames go straight up the chimney, very uncomfortable to me. i am flirting with the idea of fabricating a baffle (much like the ones fabed on other topics) using angle iron and firebricks or making a slide with a cat. i have a neighbor that has a carolina cat stove that resembles mine. i am leaning towards the cat modification, only debate i have is cost, a well built baffle will need minimal maintenece and a cat will need replaced. what i am looking for is folks that have tried this, specifically the cat modification. after seeing my neighbors stove operate i was really impressed. again, the main reason for these ideas is to keep the flames out of the chimney and try to retain as much heat as i can. i am not in a position to buy a new cat stove also i like the challenge. please elaborate on all thoughts and opinions on this topic. this is just a start so i will be working on a more detailed drawing(s). as i progress (with the help of the forum) i will post all pics and drawings for review. thanks for reading, please reply!