Materials Costs
•• 200-liter drum 400 Thai baht
•• 1 m long 4 in. wide asbestos* pipe to serve as a flue 100 baht
•• 4 in. wide asbestos 90º pipe joint 50 baht
•• Galvanized sheets for use as retaining walls around three sides of the drum
•• 4 wooden corner posts for erecting the retaining walls
•• 5 cement blocks to form outer vent in front of drum 25 baht
•• Soil or sand to be walled around the drum to help retain heat
•• Green bamboo pole (3-5 m long; 12 cm wide) for use to harvest wood vinegar