Thursday, 31 January 2013

Process of Stamping and Making Blanks in Jewelry Making

File or grind the pattern of your choice into the end of the steel bar

Impressions can be made in metal in several ways, but all involve the use of some sort of punch that has been fashioned into the pattern required in the metal. The time taken to make a tool is well spent when you want to produce several identical pieces. Stamped metal has an appearance that cannot be achieved in any other way

Keep some tool steel stock on hand so that you can make a punch when you need it rather than having to buy a little bit every time. You may need to have access to a grinder or you can fit a round carborundum stone to your polishing motor. Alternatively, use a file to model the steel and round off the edges, while the inside edges can be filed away with a burl attachment on the flexible shaft machine. Punches are made from round, square, or six-sided stock up to about -1/4 inch in diameter. Stock that is larger than this is difficult to heat properly without special equipment, and you should not, in any case, use stock that is too large for your needs. Punches are normally 31/2-4 inches long. Keep your punches wrapped in a cloth or in a dry plastic bag so that they do not rust, and keep the ends polished.

Metal that is to be stamped should be annealed and should not be too thick, because the thicker the metal the greater the force that is needed to make the depression. Metal that is ¼4-½2 inch thick is suitable.

Supports

As many pieces, all exactly the same, as you wish. 
Lead cake Small amounts of lead sheet can be bought from plumbing and building suppliers. Find an old rectangular tin can, measuring about 51/2 x 31/2 x 2 inches, cut up the lead into small pieces, and place them in the can. Heat the lead with a large flame until it melts and leave it to settle and cool. Use a strip of wood to scrape away any impurities that may gather while the lead is molten. When the lead is cold, it is ready for use. Impressions made by punching into the lead can be easily erased by heating it once more.

Pitch


Although it can be a little hard, pitch can be used as a backing for a punch.

Anvil or flat bed


1 Sandbag;  2 punch with patterned head;  3 stainless steel blanks cut and used with the AT blanking system
A stamped impression can be made into metal by placing it on a flat metal surface. Hold the punch on the metal and give it a sharp blow with a hammer. This will not form the pattern or design on the other side, although it may leave a mark, even though it does leave a fairly deep impression of the stamp on the top surface of the metal. Hallmarking is a classic example of this kind of stamping. If you are making a tool to use to impress a mark, remember that the edge of the tool will leave a mark unless it has been filed away or unless the impression of the pattern itself stands above the punch by V32-'/lo inch.

Casting sand


This very fine, cohesive material can be packed into a container and used to back metal that is to be embossed. The metal is placed face down in the sand, the punch is placed on the back of the metal and hit with a hammer. The metal will be depressed into the sand as the punch is hit, pushing the pattern through to the front. You can make a metal block to locate the punch so that a second blow can be struck without moving the punch out of line.

Leather pouch or sandbag


Making a punch Heat a piece of tool steel about 4 inches long and with a diameter of about 5/8 inch. Pack charcoal blocks around it and use a large torch. Heat the steel until it is cherry red, hold it at that color for a few seconds, and then allow it to cool naturally
 A round leather pouch, filled with sand, gives a firm but malleable backing into which metal can be hit. It is used for more general shaping than for making punched impression or embossing.

Punches


Wooden molds Metal can be punched into a turned or carved wooden mold. Alternatively, a male wooden mold can be made in conjunction with a female one, so that the metal can be put between the two pieces and the whole thing squeezed slowly in a vise.

Metal stamps and dies


Because they must be very precise, metal stamps and dies are produced by professional companies. If you are going to be making a large number of pieces with a single pattern, it is worth considering having a stamp made for you.

RT Blanking System


This bracelet was made by a series of domed pieces, soldered together, with simple stamped pieces between themThis is a special method for reproducing a large number of identical two dimensional pieces. Although it takes a little getting used to, the system does work well. It is, basically, a hand operated scroll saw, except that the table through which the saw passes can be tilted at a variety of angles according to the thickness of the metal being cut to create the model. A chart accompanying the system is used to get the angle correct. The blanks are cut from stainless steel, which, because of its strength, can be used for at least 500 blankings. The blade of the saw is tightened by a long screw arm, which is fiddly to do at first, but it does work, so it is worth persevering with it. Follow the instructions to make the first cutout shapes, and you will quickly see how you can adapt the system to create your own designs. You may find it easier to cut half a design first, then to turn it over and cut the other half rather than cutting the whole design at once.

Writer – Jinks McGrath

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