Hold it firmly against the concrete until the epoxy sets up.
Glueing plastic sheet to wall.
Using your brush completely coat the plastic sheeting and the other surface with contact cement.
Start at the top of the wall and work over then down both pressing pulling and smoothing as you go.
Contact adhesive is the industry stander for gluing formica to drywall.
Apply the adhesive in short zigzags or waves.
Work quickly so that you can attach the pieces before the epoxy sets up.
Usually there should be two coats applied before sticking the mica because drywall is somewhat porous.
Secure your plastic to the other surface with clamps.
Leave the clamps in place until the glue is completely dry.
Step 5 fix the plastic piece in place in the epoxy.
Hold plastic sheeting up to the wall and press into place when properly positioned.
Epoxy is a thick and strongly cohesive glue meaning that you can build up the glue around the base of the plastic to help hold it in place.
Here is more detail about what kind of glue to use on formica.
The glue should be applied with a sprayer paint roller or brush.
Place the first sheet against the back wall of the shower and set a level on top.
Firmly press the plastic and the other surface together.
Apply construction adhesive to the wall.