Wait between 12 and 24 hours depending on temperature and humidity. If you press your thumb onto the epoxy it should feel tacky but not leave a thumb print. If you wait longer than 24 hours you will need to scuff up the finish to apply the urethane.
Also make sure to read the directions carefully from the epoxy product of choice. It should have info listed for additional coats as well.
Thanks - put down the Devoe Pre-Prime 167 today. The concrete sucked it up like a sponge. The coverage was nowhere near 500 st ft / gal. I used 3 gallons (3 car garage 750 sq ft). And it still looks like bare concrete afterwards - with a few darker areas. Hope this stuff works!! Plan on epoxying tomorrow.
