3.5 years ago I removed our chimney pipe when I redid our roof, since then it has been laying on its side, outside, uncovered, and in the elements. We live in western Washington so lots of rain. I am now in the process of setting up our stove and am hoping I can still use this chimney. It’s two sections of Selkirk 6” chimney pipe. I now have it under cover and am in the process of cleaning them. No visible damage inside or out, they just look dirty. Is it safe to reuse these?