Annealing a piece of work usually makes it dark and dirty, owing to a thin coating of black oxide that forms on copper when it is heated. To clean it, immerse for about ten minutes in a solution of one part sulphuric acid and two parts water; then wash in running water. Be careful not to get any of this acid solution on the clothes, as it will destroy the cloth. It will not hurt the hands if it is immediately washed off with cold water.
Now polish the plate with emery cloth or steel wool, or, better still, with the wire polishing brush, Fig. 64, and it is ready for the process of planishing described in Chapter XII (Construction, Raising, Planishing).
Fig. 63. Beating up the round plate.
For the planishing of the plate the following new tools will be needed, Fig. 64:
No. 10 bottom-stake, costing 65 cents. No. 146-A tee-stake, costing 75 cents. Wire polishing brush, costing 30 cents.
Fig. 64. New tools required.
After the plate has been well polished, put the No. 10 bottom-stake in the vise and hold the plate on top of it. Start planishing the bottom of the plate in the center with the flat face of the ball-pein hammer, gradually working out toward the edge, Fig. 65.
Do this planishing carefully, striking- lightly with the center of the hammer. It is not necessary to raise the hammer more than four inches away from the plate to get a blow of sufficient force. When the bottom is smooth it should be slightly raised in the center so that the plate will rest on the outer edge of the bottom. To planish the side of the plate put the No. 146-A tee-stake in the vise and planish from the outside. Next, place the edge or border of the plate on the lapping-stake, and beat it flat and smooth with the mallet. The plate is now ready for polishing, coloring, and wax-finishing by the previously described methods.
The large oval serving tray, Fig. 66, was made in exactly the same way as the round plate, excepting that the edge or border was planished the same as the bottom. Handle may he made of heavy round wire and riveted on, or holes may be cut out with the jeweler's saw, and the edge lapped. See also Fig. 72.