Thompson Enamel has four sizes of seamless copper beads; small (RCB-3), medium (RCB-2), and large (RCB-1) spherical copper beads and one that is oval (OCB-1) in shape. Thompson also sells a bead firing rack (BR-2) which comes with 4 mandrels that fit through the holes in the beads
These copper beads are meant to be fired in a furnace. The beads are hollow. There are holes on each end or side of the bead. An easy way to prepare the copper beads for enameling is to anneal the bead to ʻ greenʼ . The bead is threaded through a mandrel and placed on the bead rack. It is placed into a 1450°F furnace for approximately 40 to 60 seconds. Practice may be necessary to get a feel for how long to leave it in the furnace. It will first start to turn a red/purple. If you see this color, remove immediately. It then turns a gray/green color.
The bead will become black if left in too long. See Glass on Metal, Vol. 10, No. 3 pp.183. Annealing to green will remove any oil or grease on the surface allowing water-based adhesives to sheet across the surface during the application of enamel A sprayer (Preval sprayer, A-7) that will produce a fine mist containing 1 part Klyr Fire and 3 parts water is needed for the process of applying enamel to the copper bead surface.
After annealing to green, hold the mandrel with the copper bead sitting on top of thumb and forefinger. Spray the copper bead lightly with the Klyr-Fire mixture on the top half of the bead. Keep the sprayer 1-1/2 feet away from the bead and hold the sprayer vertically. Lightly sift 80 mesh enamel onto the top half of the bead. It is not important to achieve a complete coating on this first go-round. Spray lightly again. This should show the areas which have more enamel or less enamel.
The top of the bead is ready for enamel application. Repeat the above application procedure until the bead is completely covered. Make sure enough Klyr-fire mixture has been applied so that all particles have some Klyr-fire mixture on them, however, do not apply so much Klyr-fire mixture that it forms a drop of liquid at the bottom of the bead.
Place bead on mandrel onto the bead rack. Using a small brush, remove the over-sift enamel at each side of the bead from the mandrel.
Dry bead for 20 minutes under a heat lamp or on top of the furnace (make sure it is thoroughly dry). Fire bead for 3 to 4 minutes at 1450°F.
After bead has cooled, it must be removed from the mandrel. This may require that the mandrel is bent back and forth until the bead breaks loose. In the firing process some enamel may fuse the mandrel and bead together where the bead touches the mandrel. It is this connection that must be broken. Wear safety glasses.
Once the mandrel has been removed from the bead, the excess enamel fired onto the mandrel is broken off with a hammer. Place the mandrel on a flat piece of iron or steel plate and hammer the mandrel, turning it so it sits on different sides, removing the excess fired enamel (fig. 13). Wear safety glasses.