Sulli is correct....There's only 3 quarts in the gallon container, leaving room for the 1 qt. of part B.
If you won't use the whole gallon to coat whatever you're coating per coat. ...just use a measuring cup and a different container.. to mix up only what you need for each coat. ( 3 to 1 ratio).
If I recall there's about a 3 hour cure period, between coats. However, The last coat before bottom paint should be thumb print tested. ( if you can leave a print without material coming off on your finger it's ready for bottom paint).
This will give the bottom paint better adhesion.
You also want to use paint rollers that are made for chemical applications. The standard latex or oil paint rollers that you find in the stores might shed.