lights instantly and burns with a high-temperature blue flame.
Figure 3-15. - Melting furnace, plumber's ladle, and melting pot.
This type of furnace consists of a fire pot and valve assembly that mounts directly on a portable propane gas tank. The tank is detachable and can be recharged with fuel. A propane furnace, as shown in figure 3-15,
Look for leaks before you light the furnace. There is always a danger of explosion from gas leakage around the connections and valves. To light the propane furnace, fold or twist a piece of paper and light it. Hold the flame up and under the burner orifice of the fire pot. Stand back as far as possible and open the fuel valve until the burner lights. When the valve is opened too much or too rapidly, the pressure of the escaping gas may extinguish the lighter flame. If this should happen, close the fuel valve immediately and then light the paper before you reopen the valve.
Molten lead is dangerous. Most accidents occur because the Utilitiesman ignored safety procedures. When molten lead is handled, be SAFETY MINDED. When moisture gets into the molten lead, the heat will cause the moisture to boil rapidly and splash hot lead out of the melting pot. If you suspect moisture in the lead, heat the lead with a torch until the moisture is driven off. Now, you can add the lead to the melting pot. Make sure the plumber's ladle is free of moisture too.
When lead is melted, certain products of oxidation, known as slag, form on top of the molten metal. The slag must be removed from the lead before it can be used for pouring a joint. Scoop it up in the plumber's ladle. Use care in disposing of the slag.
Always preheat the ladle before you dip it into the lead because a cold ladle chills and solidifies some metals. When the ladle is in steady use, keep it hot by hanging it over the edge of the pot. In loading the ladle, use the bottom of it to push back the dross (or scum) on top of the lead, exposing enough clean lead so that the ladle can be filled and withdrawn without dross. Do not disturb the molten lead more than is necessary.
Wear a face shield, gloves, and protective clothing when melting and pouring the lead. Keep out of range of flying lead even though the joint appears dry. Also, see that drops of perspiration do not drop into the pot of hot lead.
When making vertical caulked joints, you should wipe the hub-and-spigot ends of the pipes to remove moisture and foreign matter. WATER CAUSES MELTED LEAD TO SPATTER AND SERIOUS BURNS MAY RESULT. If the ends are wet, dry them with a torch. Slide the spigot end of one pipe into the hub of the other and align the joint, so the cut end is inContinue Reading