I'm about to repaint my house which has a block wall with a thin layer of smooth cement stucco. The walls have many small hairline cracks which look bad. These are not large enough to fill. Is there a special primer for this situation or should I caulk them before repainting? The walls have been powerwashed to remove any loose paint and dirt. I painted this house in 1993 with Finneran & Haley Storm Plate 30 latex which held up great. I'll be using the same paint again.