Shower Pan cracked

First use a coarse grinding disk on your electric drill to rough up the surface so you will have a good bond. Buy some fg matt and resin. Clean the surface with acetone. Cut the matt to fit and cover the entire floor. The thicker the matt you use the stronger the floor. Mix your resin and hardner. Use an old paint brush or buy a matt roller. Soak the matt thoroughly. You can add gel coat color pigment to the resin before adding hardner. Mix it thoroughly. Otherwise you can add a coat of colored gel coat after the matt dries. With practice it is easy to have a nice uniform surface. But if you havent had experience it might look a little rough but it will be sealed and very strong.