Looking through the top window, we can see a length of 1/2" x 1/2" moulding fastened to the inside of the front edge of the top frame with two screws. Below that are two pivoting pieces of 1/2" x 1/2" moulding fastened to the inside upper front edge of the middle frame with one screw each. The pivot screws are off-center, so that pointing the short end of the shorter pivot piece upward props the top frame open with a 1-inch gap, and using the longer end of the shorter pivot makes a 2-inch gap. Similarly, using the longer pivot piece provides 3-inch and 4-inch gaps when propping open the top frame.
Portable Cold Frame This cold frame is made in three stackable layers to make it portable. It can hold nine trays of seedlings, and includes a watering system that can be operated by a timer.
