Chapter IV: Copper Trays

How to make copper trays (used for pins, hair pins, cards, etc.).

(1) Round. (2) Square or oblong.

_Material:_ Piece of copper about 7 ins. square, No. 20 gauge. A hard wood block, 10 × 10 × 2 ins. thick. _Tools:_ Carpenters' gouge chisel, dividers, steel punch, shears, round peg of wood, 6 ins. long and 1 in. in diameter.

_Design:_ Take a large sheet of plain paper. Draw on it a 3-in. circle. Using the same centre, draw a 5-in. circle. This gives you the plan or top view of the tray. Below this view on the same sheet, draw the elevation, or edge view of the tray. You can make the tray as deep in the centre as you wish. Let's make this one 1/2 in. deep, that's a good proportion.

This is what we call a working drawing. If you are pleased with the design, you can go right on with the work, if not, you can change it to suit. You can see by the design that the tray is made by driving the centre of this square plate of copper down into a depression. In order to do this we must make a mould the exact size and shape of the tray centre. This is what the square hard wood block is used for.

Take your hard wood block. Draw diagonal lines across one face. Where these lines intersect is the centre. With your dividers, using this centre, draw a 3-in. circle. Place the carpenters' chisel anywhere on the circle and strike with a hammer, driving the chisel down into the wood about 3/8 in. Do this all around the circle. Gouge out the loose wood until you have cleaned out the whole depression, being careful not to go below 1/2 in. in depth (the depth of your design). Smooth this up nicely with sand-paper. The mould is now ready for the metal plate. With the steel punch, make holes in each corner of the copper plate about 1/2 in. from the edge and just large enough to fit the wire nails. Place this plate over the mould so that the centre of the plate comes right over the centre of the mould. Fasten the four corners down with the wire nails. To drive the metal into the depression we must use something softer than a steel hammer. A hard wood peg has been found to do this best. Cut a piece about 6 in. long from the end of a broom handle. Round one end up, using a file or a carpenters' chisel to do so.

Place the rounded end of the peg on the circle of the copper plate and, with a hammer, drive the copper into the depression below it. As constant hammering hardens copper so that it ceases to respond to the blows, it is necessary to soften up the metal by annealing as the work goes on. Take the sheet off the block. To do this, place the point of the chisel under the copper sheet close to the nail head and pry the nails out, lifting both copper and nail up at the same time.

After annealing, nail the copper plate in the same place as before. With the wooden peg continue driving until you fill the depression, at the same time flattening all parts of the metal that may push up. Be careful not to mar the copper at any time. When everything is perfectly flat and smooth take it off as before.

We are now ready to draw the 5-in. circle on the copper. The centre for this circle is the centre of the depression; and that is found with the dividers in the same way as you found the centre for the bottom of the bowl. Make the circle on the copper. With the shears cut along a little on the outside of this line. Smooth up and round the edges of the tray with a mill file. Rub out file marks with a little piece of emery cloth. If the hammering has been uneven some parts of the copper will have stretched more than other parts and the tray will not lie flat when placed on a table. To level this up, place the tray top side down upon a bench or table and strike gently with a mallet on the surface. Holding the mallet near the head one can control the blows and be able to strike gently. But if it is held toward the end of the handle the blows will not be uniform. This applies to all hammers, whether of wood or steel. You will notice as you do your hammering the high spots will settle down and gradually flatten. The tray is now ready for cleaning and polishing. This is done in the same way as you treated the bowl.

_Decoration:_ Round trays may be decorated in many simple ways by drilling holes in the rim, and then sawing out designs to suit one's fancy, or they may be notched at intervals. Nothing is more decorative though, than the embossed or repoussé design, made by beating from the back and raising the metal on the face above the level. One of the designs given here shows the embossed, and the other shows a combination of the embossed and sawed out work.

_The value of the mould:_ It may seem to you like a lot of work to make a mould just for this round tray, but it can be used many times for making this kind of tray and also for trays of similar shape, like bowl covers, etc. Most of the jewellery nowadays is made in moulds, wood, steel, or lead. Copper, silver, and gold medals, pins, rings, tea and dinner sets are all made by the mould or die method. This mould you have just made is only a simple one; however, complex ones are made in the same way. The skill all lies in making a very good design first and then in making a very smooth mould to fit the design. After one or two trials it comes easy enough. The chapter at the end of the book will explain die and mould making in modern copper, silver, and goldsmith shops.

SQUARE TRAY

_Material:_ Copper, 6-1/2 × 4-1/2 ins. No. 20 gauge.

_Tools:_ Shears, square, bench vise, round hard wood peg; dividers, copper vise jaws.

_Design:_ Determine first whether the tray is to be oblong or square. This material makes a tray 6-1/2 × 4-1/2 in. Draw this size oblong on a sheet of paper. The rim of the tray should be 3/8 in. wide. Draw an inner line all around, 3/8 in. from the outside. Below this draw your elevation, or edge view, showing the depth of the tray. In this design it is 1/4 in. deep.

First see that your 6-1/4 × 4-1/2-in. piece of copper is squared. Now draw your inner rectangle on the metal. To do this, set the dividers 3/8 in., and with one leg against the edge of the copper, draw all around the four sides, marking the lines on the metal. You now have a flat sheet marked ready for bending. Place the sheet of copper between the vise jaws, the inner line even and on a line with the vise.

The hard wood peg should be cut to a flat tapered end. This flat end of the peg is held at an angle of about 45° against the copper plate, just above the vise jaw and against the line of the rectangle. With the mallet drive gently. By doing this the body of the tray is pushed in, but the rim is kept straight in the vise. Repeat this all around. You'll have a tray like the sketch. If the body of the tray is not deep enough put it into the vise again and keep driving it until you get the depth you want. The inner corners will be found to be rounded, as they should be. Round off the outside corners to match. File the edges round and finish with an emery cloth, clean and polish as explained before.