The two of the liquids used to heat metal and or to cut the metal is oxyen and acetylene. Whenyouight the torches the flame is relatively large and can serverly burn your hand and leave scares for life. The valves should be open all the way to allow as much liquid as possible in the torches. The torches can lower the flame to make it more direct or you can even make it large to cover alot of the metal. These torches come in cylindrs that are about four ft high and about eight ince in diameter. The cylinders are also refullable. The torches are carried on a trolly which maks it easy to move around. I have used these torchs before. The first time I was neverous, but after a while I felt comfortable around the torches. I have yet to cut or heat someting but that I can do next year in grade ten. I fell that I can cut or heat something right now if I wanted but I think that I can wait until next year. The next thing that he the teacher showed us was the knee mill
