Clean the crack with a dry toothbrush to remove any dirt or residue build-up.
Wipe with a dry cloth to remove the loosened soil and remove any moisture found inside. Push the cloth into the crack using a fingernail to ensure that it is dry.
Mix the two-part epoxy according to the package instructions. You only need a small amount of epoxy for a plastic crack, so opt for easy-to-use epoxies. These come pre-measured, making them easier to mix.
Insert the epoxy into the crack using a syringe, toothpick or spatula, depending on the size of the crack. Ensure the epoxy is far enough in that it coats the back of the crack.
Wet a rag and carefully smooth the epoxy so it is flush with the faucet's surface.
Leave the epoxy to dry for up to eight hours, according to package instructions.