The Cortez is a classic lightweight running shoe design produced by Nike since 1972. Most of the Cortez styles are constructed using combination nylon and leather uppers with cushioned foam soles. The soles on most Cortez shoes are glued on and tend to separate over time. No sewing or visits to the cobbler are necessary to fix a Cortez foam sole that is falling off. A small amount of the right adhesive can inexpensively and effectively repair the sole on a pair of Nike Cortez shoes.
Spread the separating section of the foam sole gently away from the upper so both inner surfaces are revealed. Remove dust and debris on and in between the two spread surfaces with a firm bristle brush.
Scuff the interior surfaces of the sole and upper lightly with a piece of medium-coarse sandpaper. Brush out any loose material created by the sanding. Wipe down the sanded surfaces with an alcohol-soaked paper towel or sponge.
Wait for the alcohol to dry completely. Apply a thin layer of the flexible adhesive to both prepared surfaces with a wooden Popsicle or craft stick. Hold the surfaces apart to allow the curing process to begin according to the adhesive manufacturer's instructions.
Press the glue-covered surfaces together. Clear off any excess adhesive that squeezes out from the side using a clean Popsicle or craft stick. Insert a sealed and filled water bottle into the shoe so the weight is over the repaired section.
Place the Nike Cortez shoe on its sole on a flat surface in a well-ventilated area. Allow the adhesive to cure overnight or according to the manufacturer's instructions. Trim unwanted adhesive that has hardened on the side of the sole with the blade of a utility knife.
Many shoe repair adhesives can also be applied to the bottom of the sole to extend the usefulness of a worn sole. Use the same sanding and cleaning techniques to prepare the bottom of the sole for the adhesive.
Avoid water in a repaired pair of Nike Cortez shoes if possible. Warm water washing is especially harmful to most shoe repair adhesives.