Hello, I am trying to figure out how to seal off an 11 inch galvanized steel pipe that used to connect an old wood stove to my chimney. I got rid of the stove and will no longer be using the chimney. The pipe now has about 2 inches that is sticking out of the brick wall. I was planning on buying a round flue plug but for some reason I'm having a really hard time finding one that is 11 inches in diameter. I'm open to any suggestions that you might have. Thanks in advance for your help