Approximately 1/2 hour is generally recommended for our primer. Other primers may vary, so always follow the instructions for your specific primer. Most 1:1 primers such as your epoxy primer can be coated within the first few hours, but single part primers actually dry instead of cure. These single part primers often need to fully dry before having a two part product applied. Always read the instructions provided to ensure proper adhesion.
It is also usually recommended that any primer which has fully dried or cured be lightly sanded or scuffed to ensure the best possible adhesion.