We had total Wooden cabinets from 1961 which were unpainted, so we sanded and did numerous coats of primer only to cover the knots and oil stains. Now I think we could have applied a knot blocking product. We also painted each of the backs and interiors of drawers and http://bookmarkbirth.com/story4552769/the-2-minute-rule-for-painting-thermofoil-cabinets