Hello, i have been lurking around here for some time just always looking at past posts. I just finished installing my voglezang performer non-cat stove and have been burning it for about 2-1/2 weeks. i have been a little paranoid about creosote so i checked the stove pipes after a week of burning, clean pipes. Just checked the top of the chimney today and found the tar like creosote. So i pulled the stove pipes apart and as you can see in the pics it was filled with gunk. I guess my question is how bad is bad. judging by my pics do i need to clean it before starting another fire? And the other is what caused it. I have a 6" 35' SS flex liner with a 1/2" insulation kit. I have been checking my oak with the HF moisture meter and its mostly in the 13 to 18 % range. When i am burning i get great secondaries and my stove top temp is 300 to 600 in a normal burn cycle. One thing i have been concerned about is my flu temp, i can't get it much over 300 degrees. Another option is this past week my wife was burning all day while i was at work and i know she has not had a lot of experience getting used to the stove and what to look for. I know she has had some problem's getting good temps and such.