This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
Having occasion to do a large amount of counter-flashing in a new wall where the mortar was soft and the joint too large to use an ordinary nail or the regular flashing hook, I made hooks from No. 24 gauge galvanized iron, having hooks of extra size and strength, as shown in the sketch. The size of the hook is 1 3/4 by 3 1/8 in. On each side edge, 1 1/8 in. from one end. I cut teeth, A A, and clipped the corners of the opposite end at an angle. The end at B was turned down at right angles and the points A A bent in the opposite direction. I placed the counter-flashing in the usual manner, with the projection B hanging down and the pointed end of the hook in the joint, and drove or pushed it in tightly. The points A A will catch on the under side of the brick and hold solidly. - Contributed by Ralph M. Chatham, Orleans, Indiana.