The purpose of this book is to explain the conversion of a typical 23" or 28" electric kiln to a TDI propane gas fueled downdraft kiln. The book provides a detailed description of the theory, construction process, parts required with sources, and the basic tools needed. The idea is to promote at-home or small studio reduction firings that can produce very reliable and repeatable results. For those who want to continue exploring and learning in an environment of less certainty, reduction firing can be a fun path. Reduction firing requires gaining experience with firing schedules, reduction techniques, and glazes - commercially available or your own mixing. This Second Revised Edition published April 2022.