"Making a Cardboard Box Solar Soil Sterilizer" by: Jon Detka  This solar oven design is adapted from a design created in 1976 by Barbara Kerr. The construction of this oven will allow the user to create 'weed free' soil for plantings.  This design is a smaller scale construction plan to demonstrate the basic plan.  If you will be sterilizing large amounts of soil for a large group then it will be necessary to use a larger box.  The construction and use of this oven could also serve as an optional 'weedy' prevention activity. This oven can be used in conjunction with the "Weedy Sock/ Weedy Tread" activity. This solar oven can reach temperatures of 275 degrees, hot enough to cook food and kill germs in water. We will be using it to eliminate bacteria and  weed seeds from collected soil.   This oven can be used virtually year round in our temperate environment. Weed free soil is dependent strictly on temperature. The oven must reach a temperature of at least 180 degrees (F) for seed sterilization to occur. Materials Cardboard One large box One smaller box that will fit inside the big box and have a 2-3 inch space between the two. Cardboard scrap sheets Paper Old newspapers Black construction paper Other Materials Aluminum foil Heavy-weight clear plastic laminate Cut to the dimensions of the large box. Duct Tape Thermometer Tools Box Cutter   How To Make Your Cardboard Box Solar Soil Sterilizer         1.Take your large box and line the bottom with insulating materials like crumpled newspapers.         2.Set your smaller box inside the big one (this will serve as your oven).         3.Fill the space between the sides of the two boxes with crumpled newspaper.         4.Use cardboard pieces to fold over the insulated space between boxes.  Make sure to pack it tightly.         5. Line the cardboard pieces bordering  the packed space between the boxes with black construction paper.         6. Line the sides of the inner box with aluminum foil adhered with non-toxic glue         7. Tightly secure or lay your plastic on top of the large outside box. Make sure to secure the plastic around the sides with duct tape so no air can           escape     Feel free to improvise and improve the design while maintaining its essential structure. Images coming soon.

site.design.by.Jon Detka