In this video, Tom Carpenter explains how to filter vegetable oil into bio-diesel at home. After collecting a large amount of waste vegetable oil, place 30 gallons of it into a modified (by removing the top heating element) water heater. Use a pump and hose to circulate the liquid through the water heater. Heat the oil to 120-130 degrees Fahrenheit. In a separate container, mix methanol and sodium/potassium hydroxide (methoxide). After disconnecting the heating element from the water heater, use a tube to add the methoxide into the oil, allowing the pump to circulate it for 3 hours. Transfer the mixture into a separate tank, allowing it to sit for 24 hours. After 24 hours, the mixture will have separated into two distinct layers: the top layer is raw bio-diesel, and the bottom layer is glycerin. Drain the glycerin (either saving it for other purposes or to dispose of). After draining the glycerin, "wash" the bio-diesel by adding water to it several times, allowing it to settle in between washes. After washing it, run the bio-diesel through a filter. The bio-diesel is now fully processed and ready to be used.