how to creating an insulated box

How to Creating an Insulated Box.

There are lots of ways to make a homemade cooler using readily available insulating materials. Using a lidded box, foil, and recycled packaging materials, you can make a small, simple cooler. For a larger, more effective design, line a cardboard box with foam board. If you need something more portable, you could also sew an insulated lunch bag to keep items cold when you’re on the go.



Steps.



Remove the top flaps from a cardboard box. Use a pair of scissors or utility knife to cut off the top flaps. Keep in mind you’ll be building layers of foam about 6 in (15 cm) thick inside the box. Choose a box large enough to hold all of that insulation and still have room to store foods and drinks.

For example, if you use a 24 by 24 in (61 by 61 cm) box, the space available for storage will be 18 by 18 in (46 by 46 cm).

A cardboard box is the easiest choice, but a large plastic tote would work. You could also make your own box out of wood.



Line the box with a trash bag, shower curtain, or plastic tablecloth. Place a trash bag, or another type of waterproof material, into the box as if you were lining a trash can. Press the bag into the box’s corners, and take care not to tear the bag. Keep the bag flat against the sides of the box, then trim the bag so it’s flush with the top of the box.

Duct tape the bag to the top of the box; add strips of tape along the box’s entire top edge. Give the bag some slack so there’s extra material at the bottom corners. It’ll tear easily if it’s too tight.

The waterproof layer will help keep melted ice or condensation from getting the cardboard soggy. A trash bag is inexpensive and readily available, but a shower curtain or plastic tablecloth would be sturdier.



Cut 5 panels of 1 in (2.5 cm) foam to line the inside of the box. Use craft foam boards or sheets of foam board insulation. Measure the box’s bottom and sides, cut a panel that matches the box’s bottom, and make the side panels 2 in (5.1 cm) shorter than the box.

Cut 2 of the side foam panels 2 in (5.1 cm) shorter to account for the thickness of the other 2 panels. Suppose you have a 24 by 24 by 24 in (61 by 61 by 61 cm) box; make 2 of the panels 24 in (61 cm) long. Since the panels are each 1 in (2.5 cm) thick, make the other 2 panels 22 in (56 cm).

Cut with the grain of the foam to keep the edges straighter.



Glue the foam panels inside the box. Start by gluing the bottom board to the base of the box. Take care not to tear the waterproof layer. Then glue a foam panel to each side of the box's interior.

Once they’re glued into place, the tops of the side panels should be 1 in (2.5 cm) below the box’s top edge. Each side is 2 in (5.1 cm) shorter than the box, but the bottom foam panel adds an extra 1 in (2.5 cm) to their height.



Use 4 more foam panels to create an inner box. Make 2 of the panels about 4 in (10 cm) smaller in width than the sides of the box. Cut the other 2 panels 6 in (15 cm) smaller than the box’s sides. All 4 sides should be 1 in (2.5 cm) shorter than the height of the box.

Glue the 4 panels together to make an inner box. This smaller inner box is actually the storage space. You'll fill the gap between the inner foam box and the panels that line the cardboard box with insulation. All of these layers of insulating material will help keep the cooler nice and cold.



Glue the inner box into place. Center the foam box inside the cardboard box. There should be a 3 to 4 in (7.6 to 10.2 cm) space between the 2 sets of foam panels on all 4 sides. After double checking the fit, glue the inner foam box into place.



Fill the gaps between the panels with vermiculite or spray foam. Pour vermiculite between the panels, or use spray foam insulation. If you use spray foam, pause between applications to allow the foam to expand. If it expands beyond the tops of the panels, give it an hour to dry, then trim the excess foam with a utility knife.

In a pinch, fill the gap with packing peanuts, bubble wrap, or Styrofoam. Fiberglass insulation would also work.



Make 4 strips of 1⁄2 in (1.3 cm) foam board. Cut strips of foam wide enough the cover the insulation-filled gaps. If each gap is 4 in (10 cm) wide and each foam panel is 1 in (2.5 cm) thick, the cover strips should be 6 in (15 cm) wide.

Cut 2 of the strips, then set them over the gaps on parallel sides of the box. Measure the length between the 2 covers, then cut 2 more strips to match that length.

Be sure to use 1⁄2 in (1.3 cm) thick foam board for the strips to leave room for the box’s lid.



Glue the cover strips over the gaps. Apply beads of craft glue over the foam panels that line the cardboard box and the ones that form the inner box. Then set the cover strips into place over the insulation-filled gaps.

Remember to place the longer cover strips across from each other.



Use a sheet of 1 in (2.5 cm) foam for the lid. Measure the perimeter of the top of the box, and cut a foam panel to match. Since the strips that cover the insulation-filled gaps are 1⁄2 in (1.3 cm) thick, there should be a 1⁄2 in (1.3 cm) lip formed by the sides of the cardboard box. This lip should hug the sides of the lid.

If you’d like, glue handles or knobs to the top of the lid so it’s easier to remove. If you made a wooden box, you could make a wooden, foam-lined lid and join it to the box with a hinge.





Things You'll Need.

Insulated Box.

Large cardboard box.

Trash bag, plastic shower curtain, or plastic tablecloth.

Scissors or utility knife.

Duct tape.

10 1 in (2.5 cm) thick foam board panels.

1⁄2 in (1.3 cm) thick foam board panel.

Craft glue.

Vermiculite or spray foam.