Make a Cooler out of a Cardboard Box

Ever been outside on a hot day with cold drinks warming up quickly and no cooler? Follow these instructions, and it won't happen again.

Steps

Obtain a box that has similar dimensions as the cooler you want.
Wrap the box in packing tape until the outside has at least one layer of tape on it. This will help to hold the box together for when you add the insulation foam.
Put your beverage cans into the box so they are standing vertically. Keep at least some spaces{{safesubst:#invoke:convert|convert}} between the sides of the box and the beverages, and between each can.
Spray the insulation foam whenever the beverages aren't in the box. This is where all that tape comes in handy.
Close the box quickly and tape the box closed. You need to do this so that the foam stays compact.
Cut away some of the insulation foam from above the beverages. Cut out just enough so that you can remove the beverages.
Close the box and put a piece of tape from one end of the box (it must be perpendicular to the top flaps), and stretch it over to the other side of the box but don't press the other end to the box. Fold it over so it doesn't stick to the box. This will hold the box closed when you aren't getting beverages out.

The top piece of foam should come out as one block.
Make sure the beverage cans have straight sides so you can remove the cans without destroying the foam.
Try filling the box with foam in two steps. First fill it so the foam comes up about 3/4 to the top of the cans. Then put a piece of polyethylene sheet from a garbage bag over the cans and fill the box to the top -- closing the sides as previously instructed.
When the foam sets, cut between the top foam and the sides of the box with a keyhole saw or long bread knife.