In a blender of food processor blend the flour, 1/2 cup plus 2 tablespoons water, milk, eggs, butter and salt for 5 seconds. Turn off motor, with a rubber spatula scrape down the sides of the container, and blend the batter for 20 seconds more. Transfer the batter to a bowl and let it stand, covered, for about an hour. The batter may be made 1 day in advance and kept covered and chilled.
If necessary, add more milk by tablespoonfuls to batter to thin to consistency of heavy whipping cream. Heat 8inch diameter nonstick skillet over medium high heat. Brush with melted butter. Pour 3 tablespoons batter into skillet and swirl to coat bottom evenly. Cook until top appears dry, loosening sides of crepe with spatula, about 45 seconds. Turn and cook until brown spots appear on second side, about 30 seconds. Turn crepe out onto plate. Repeat with remaining batter, brushing skillet with butter and stacking crepes on plate.