Lesson 1: Sphere

Lesson 2: Sphere

• Cut out 2 disks with the same diameter- either by saw or with the disc cutter. The disc cutter has a limited range of diameters.
• Anneal.
• Dap using the block and punches.
• Your disk should sit 1/3-1/2 of the way down in the first depression.
• Listen for the solid ping of the punch, not the hollow thud.
• After annealing, your disk is dull. As it comes in contact with the surface of the dapping block it will become shiny. Look for this to ensure that you are dapping evenly.
• Anneal after every 3 hole shifts on the block.
• Measure your hemispheres: 2h=d
• (two times the height of your hemisphere should equal the diameter of your hemisphere)
• Continue dapping until you have the measurements correct.
• Find the dapping punch that fits your sphere tightly, and place it in the vise.
• Planish with the flat side of a planishing hammer in concentric circles from the center out to the edge. Planishing trues the shape/form to the stake you are using. It is the best way to make certain that you shape is accurate and even.
• You should always hit in the same place on the punch, and rotate your hemisphere around.
• Your hammer marks should be even and cover the entire surface. You do not need to hit hard- this is fine-tuning your shape, not smashing it!
• File the edges of your hemispheres flat.
• Measure to double check that 2h=d is still true.
• Make any adjustments if the measurements are off.
• Drill a small hole in one of the hemispheres.
• Solder hemispheres together.
• You can use binding wire to hold the 2 pieces together- the binding wire should be perpendicular to the seam. Place the bound sphere on a mesh plate or in the annealing rocks to prevent it from rolling away. You can also use the straight pins to create a “box for the sphere. 
• Pickle.
• Put sphere into baking soda/water mix to neutralize any remaining pickle. When the piece stops bubbling, the pickle is neutralized.
• Draw out baking soda solution with syringe, flush interior with water to make sure all pickle residue is gone, and dry.
• File off the planishing marks- make sure that you file smoothly- your sphere should not look faceted!!
• Sand with 320 and 400 grit sandpaper.

Tips and tricks:

• If you want the disks a different size than the disc cutter allows, use your dividers to mark the circle and pierce out. File the edges so that the disk is as close to a perfect circle as it can be.
• If you have finished with a hole, and the next one is slightly too small, take a smaller punch, and hit a few times in the hole you just finished. This will bring the edges in slightly.
• Then use that same smaller punch to hit in the center of your piece on the new hole to help get it down in the hole without marring the outside surface on the edges.
• If your hemisphere gets stuck in a hole, use a smaller punch and tap a few times to release it.
• When you dap, the outside lip of your hemisphere is at an angle. You will be filing off that angle to solder. This affects your height measurement. Err on the side of making the height slightly larger (app.5mm) so that when you file the lip flat, the measurement should be perfect. You can file down more if it is still too tall.
• After filing the edges flat, use the scraper to remove the bur created by fining. This will let you see the edge clearer and allows you to double check that everything matches up correctly.
• When drilling on a concave/convex surface, always drill from the concave side. The form will automatically center the drill bit at the lowest point eliminating the need to center punch.
• Instead of using binding wire to hold your hemispheres together, you can push 4 straight pins into the board to form a cage around your halves. For best results, the pins should bend in towards each other at the top.

Homework:

Create a sphere from 20ga brass. The diameter of the sphere should be no smaller than 3/4 inch. The sphere should be sanded to 600 grit. I will be measuring and rolling your spheres on a flat surface to check accuracy!!

Due: Beginning of class September 19