Using lead to weight your pinewood derby car is one sure way to get an edge. You can melt lead at home using a portable burner and some household cans, but it is not a job for kids. Lead melts at a lower temperature than most metal, but molten led is still extremely hot and can cause severe burns. Lead is also hazardous and can cause serious health problems if ingested, so take every care not to come into direct contact with it, and melt it in a well-ventilated area. Once the lead is melted, add it to the cavity created in your pinewood derby car. The weight of the lead will provide extra speed.
Find an outdoor space or area such as a garage with excellent ventilation.
Heat the lead in your receptacle or can by degrees. If you are using a can, bend the edge of it slightly to create a pouring spout prior to heating.
Start the heat at a low setting and move up gradually. This will also help reduce fumes. Ensure adequate ventilation if working in an enclosed area. Use a fan placed in a window to help draw the fumes out of the area if you are not outdoors or can't open a garage door.
Once the lead has become liquid, it is ready to pour. Be extremely careful; lead melts at over 600 degrees. Use gloves and work briskly but with care, pouring the molten lead into cavities in the car you have carved.