Never tape flue pipe when Rotted. Glue will dry out from heat and fall off. Also painters tape was used in this D.I.Y repair. That can burn over time.

On heat preventive maintenance a homeowner, shows off her D.I.Y. Flue Pipe repair. She was very proud of her DIY repair using painters tape to close the rotted out holes on her chimney pipe. Luckily the weather has been warm enough that she has not needed to run her furnace yet. As soon as I saw the painters tape on the flu pipe, I told her I had to shut down her furnace. She was not very Happy that her furnace was getting shut off to protect her from carbon monoxide poisoning. I told her the only way I could turn it back on is after I replace the rotted out flue pipe that had holes in it and was crumbling in other spots. After thinking about it for a little while she told me to go ahead and replace only the one rotted pipe. I told her I was ordering a few pieces I wasn’t gonna play around the old 90s and have them break on me and then have to run out and buy them. Therefore I replaced any of the pieces of flue pipe I felt was necessary. This should never be done, I am not against anyone doing a DIY repair. I do them all the time for myself. Yet if a flu pipe is rotting replace it. Protect yourself and your family, how would you feel if anything happened to your family because of a DIY repair Like this one