Step 1: Make an Oval
Take a washer and hammer it on it’s edge. The washer will start to take on an oval shape. At the same time the washer will begin to fold in half. When this happens, lay it down and hammer it flat again.
Go back and forth between hammering the washer on it’s edge and hammering it flat again until you have the shape you want.
Step 2: Shape the Barrette
Lay the washer down on a piece of scrap wood. Use a socket to form the shape by hammering it against the washer. While you do this, compare the washers so they end up identical.
File the edges of the washer until it’s rounded all around. Start by taking the edge down at A 45 degree angle. Ease the edge further by rolling the washer against the rotary tool. Go at it until the edges taper nicely towards the center.
Use 400 grit sandpaper to smooth it out. Move on to 1000 grit, 2000 grit, and finally polishing compound on a polishing wheel.
Step 3: Make the Detent
Mount a nail into a drill press. Spin it round and use a file to reduce the head until it hides behind the barrette.
Next use the file to shape a ball close to the head of the nail. Snip the detent off and remount in the drill press so the ball end protrudes.
File the ball side until it’s the shape you want.
Step 4: Make the Hinge Clip
Take a paper clip and wrap it around another as shown in the picture. Remove the coiled wire and cut it down to size. Place the cut section back on a section wire. Make the edges of the hinge flat by filing it down with a grinding stone. Do this for each side on both hinge sections.
Extend a paper clip and form it as shown in the picture. Use socket to form a round shape in the clip. Place the clip in the hinge section. The clip will help keep the hinge in place during soldering. Otherwise the hinge will roll right off the barrette.
Step 5: Solder
Apply flux paste to the soldering areas. Place the detent on one side and the hinge with the clip on the other. Solder them in place. The clip will solder into the hinge but it can easily be worked free while leaving the coiled section in place.
Step 6: Oxidize the Metal
Remove the clip from the barrette. Wipe any finger prints or dirt from the barrette. Flip it over and heat it with a torch. At first the metal will turn brown. Very shortly thereafter it will turn blue. It you hold it longer it will turn black. As long as it's clean it will oxidize uniformly.
Play around with it. If you don’t like the color, sand it off with 2000 grit paper and do it again.
Keep in mind while you do this the solder will liquify. It will stay in place as long as you let it cool and re-harden before you handle it.
Step 7: Put It Together
Replace the clip and adjust it so it snaps over the ball detent. If you want a larger barrette, simply start with a bigger washer.