Glenn, Here is a video of my melting furnace. I have been using waste oil quite some time now this is my third furnace. It has a 10" bore which is about 12" in height. My crucible is 6" X 9" well casing pipe. This furnace will melt twenty pounds of aluminum in twenty minutes from a cold start. The flame out is caused by not enough preheat, and to much air. Another thing when you start to add oil, do it very gradually, or you will flood to furnace. A needle type valve is a must because you need have fine adjustment on the oil. You can preheat with wood, or charcoal but the ash blowing out afterward is messy. I prefer to use propane for the preheat, because it is quicker, and a lot hotter. I only hope the forge dose as well. Melting Furnace
Hope this helps
Larry