Poly goes through several phases of drying or, more precisely, curing:If you are using an oil-based Polyurethane, you can usually touch the surface without leaving prints or apply another coat after 24 hours. You can carefully start walking on a floor (with socks) 1-2 days after applying the final coat. Allow a table finished with Poly a bit more time to dry though – consider a careful use after 2 to 5 days. However, wait until the stickiness of the surface is gone before you use it in a normal way and put things on it for a longer time. This should be the case after 1 to 3 weeks.Water-based Poly requires significantly less drying time: Additional coats can be applied after 3 to 4 hours and you can walk on a floor wearing socks after 4 – 8 hours.These numbers depend on a number of factors, of course. These include but are not limited to the type of poly that you are using, the humidity, the temperature, the quality of the sanding etc.