Tinted paint takes for a longer time to get rid of. The colorant slows down the drying time. Also, if the primer was tinted this could be the problem as well. Shellac primer can not be tinted with over two ounces of colorant. I would depart it on your own http://cashzfzoc.blogs-service.com/17253215/the-2-minute-rule-for-painting-kitchen-cabinets-white