Jewellery Making Workshop
Metalshop, Leeds College of Art
18 April 2013
More photos on Flickr.
Health & Safety
- Use common sense - keep bags out of the way, do not run, look after the tools and keep out of the way
- Know what to do in an emergency. Accident: turn machine off and get first aider or phone for help. Fire: leave by fire exit and meet in car park to sign off the sign in sheet.
- Ask technician for help with machinery, don’t rely on other students knowing the correct information.
- May need an annual refresher for the metal and jewellery room.
- Use protective items – goggles, gloves, apron, ear defenders – as and when required.
- Were sensible clothes and shoes (no saddles or bare feet). Tie hair back, and remove jewellery and scarves.
- Remember hygiene and wash hands when you leave the workshop and don’t eat or drink in the room.
Using copper today as it’s a cheap material and allows you to do lots of different works on it. It has a high melting point. It is bendy, soft but resistant. It will oxidise (goes green). Lots of pressure from steel tool swill damage it.
To cut metal
Measure out the copper using the square. You can scratch it with scribe. Can also use permanent ink and later use chemicals and heat to remove it.
Wear gloves because the edges of the metal will be sharp once cut.
Options for cutting
BENCH SHEARS – line up and pull handle down, pulling to the left
TREADLE GUILLOTINE – look over the top to identify the edge of the table. Line up your cutting line with the edge of the table and the other edge to stay straight. Keep away from the edge of the metal as it may be sharp. Stand on treadle and wobble to force down, release gently. Pick up cut parts when no one else is using the machine. Cut brass, copper, and aluminmum up to 1.5mm thick. Cut steal up to 1mm thick. Some plastics can be cut, but not Perspex.
Other machinery available
METAL FOLDER - put metal in and straighten along fold line. Lift with the black handle on the edge then pull up bottom blue handle to fold upwards. Free structured bends.
ROLLER – tighten up bottom when the metal is in place. Adjust back wheel to match the size of the roll you want.
TUBE BENDER – will bend tubes. Good for furniture and sculptures.
VACUUM FORMER – best to mould around a solid 3D shape with no undercuts so it can be removed. Use wood (probably MDF) as most other perish during use or after one use. Will have a flat back which is OK for symmetrical shapes where you can join two halves together later. Use high-density polystyrene, Perspex and acrylic are too brittle, less flexible and don’t pick up the details.
DOME BLOWER – create a bubble shape using acrylic.
ETCHING TANKS - photos and images transfer to etch or eat through.
TORCHS – use for welding where two of the same materials are joined with the same material. Also use for brazing where metal is joined using a metal with a lower melting point, eg joining steel with copper.
MIG WELDER – for steel
TIG WELDER – very versatile
PLASMA CUTTER – for thick metal up to 16mm. Rough cutting method which is good for organic shapes, or you can cut around a wooden mould used as a guide. Not suitable for finer materials.
ANGLE GRINDERS – for cutting, shaping, and forming
BANDSAW – for ferrous metals like brass, copper, and aluminium. Not suitable for thin materials, can do 3/4mm straight cut. Can’t do details.
SANDERS – two metal sanders and one plastic.
LATHE – shaping materials. A large centre lathe is available as well as a hobbyist (smaller). Put work in chuck and introduce cutters to carve, shape, turn metal. Hard to use and takes a while to build skills. Good for steel, brass, aluminium, sliver, gold, most plasctics, and wood (more precision than on woodshop lathes)
MILLING MACHINE – work attached to bed and the cutter moves (opposite to lathe). Precision carving of metal, but copper is too soft. Woodshop has better equipment for plastics and wood.
CHOP SAW – cutting tubes into small sections. Much quicker than using a hacksaw and doing it by hand.
Plastic is available from the metal/jewellery workshop. There’s a wide range available, but if they’re not right you can look at the Himdley’s website and order your own, or give the technician the product code. Potentially seven to fourteen day wait.
Need to change the molecular structure of the copper to make softer and easier to work with. You do this by heating it was a blowtorch until it turns a cherry red colour, even if its just for a moment. When you work the copper it will get hard again as you put pressure on it.
Leather gloves and aprons are available if you are worried about the heat.
Get some cool tweezers (try to keep them cool by avoiding getting the flame near them). Place the metal on the heat bricks on the hearth. Set them up so there is a space for air behind, this give a more even heat distribution.
The torch has a pilot light that stays on all the time. If its not on get the technician to light it for you (never light it yourself or with a lighter). Turn the gas on turning the dial on the handle. Then slowly turn on the oxygen to get a stronger blue flame. The warmest bit is the area between the blue and the red so wave that over the metal moving away regularly to check for the colour change. When ready turn off the oxygen, then turn of the gas.
The copper has been oxidized and looks black. It now needs cooled and then placed in Safety Pickle. Like the copper down using the cool tweezers and put it in the bowl of water. They can be removed immediately after by hand.
Put on goggles and remove the lid to the Safety Pickle. Lift out the basket until it is above the liquid. Gently place the metal in the basket then slowly lower it back into the diluted acid. Leave in there for three to five minutes (if you leave in for week the surface with start to etch). Remove with the copper prongs and then rinse well with water. Once rinsed you can touch the metal and dry it with a paper towel. If you get splashed wash off with water, clothes will probably bleach.
You can use the rolling mill to emboss onto metals. Steel won’t work (will probably damage the machine), and glass and plastic will just shatter.
To emboss you need something to press into the metal, organic items work best.
Put metal into the mill and hand-tighten to fit. Roll out and place item on top of the metal. Tightened or loosen to match the item to be embossed and feed back in. If the metal curls it can be hammered flat using a hide hammer and gently knocking along the edge.
Metal can only be pushed through and embossed once. To emboss a second time would remove the first embossing. The metal may also need kneading again to soften it enough to accept the embossing.
Sawing into metal
Mark the metal with the shape. You can do this with permanent ink, making shapes with masking tap, or gluing a drawing on to the surface using pritstick.
Use a piercing/jeweller’s saw. The blade is insert by placing the saw between the work table with the handle hitting your stomach. Undo the bottom butterfly bolt and place the end of the blade into it. The teeth of the blade should point towards the handle. Put your hand on the handle and push the saw towards the bench. With the other hand insert the blade at the top and tighten the screw. The blade should ping a little when you strum it, which is important as it must be in tension.
Put your work on the peg on the workbench and put your free hand gently on the metal to guide it, but keep fingers away from the blade. Keep the metal near the back of the gap. Start sawing up and down with the saw at 90degrees to the metal. Keep the saw moving and the work moving.
The blade costs 20p each. If you snap yours put it in the yellow sharps bin by the sink – don’t leave it sitting about.
Making a ring
Try on the ring samples and get the letter from the one that fits. You are better getting a size a little bigger. Check the circumference on the sizing chart and measure out a piece of metal, rounding up the decimal point, and marking with a scribe.
Once cut file the ends to make a good flat and clean surface for soldering. Make sure you square it off by keeping the file and metal at 90degress.
Knead then pickle the copper. Make the metal into a tear drop shape with your hands then gently tap the top with the hide hammer so the two edges meet and are level together (not stepped). It doesn’t have to be ring shaped at this stage. Put it on to a heat tile for easy transportation without getting it greasy.
Get a dish and some borax. Clean the dish out and put some water in it. Place it on a bench on top of some paper towels (the dish may leak) and grind the borax in until the water turns semi-skimmed-milk white.
Get some silver solder (35p) and sand it to remove grease, avoid touching the cleaned area. Cut the strip a little long ways and then side ways to make small bits. Put them in the borax water. There are five grades of solder and each works at a different melting point. Some projects may need you to layer it up and you would stat with the ‘hard’ and work through to the ‘extra easy’, this way the original won’t melt as you work.
Using a paintbrush, brush the borax water on to the area of the ring to be soldered (if it was a good project or expensive metal you would cover all of the ring). Use the paintbrush to lift the silver from the dish and to put on to the join in the ring. Use just enough.
Move the ring on the heat tile to the hearth and heat up gently using a red/orange gas flame. The borax should turn white a bubble a little. Then turn on the oxygen and turn down the gas to make a short blue flame. Heat the whole ring in a circular motion for even heat distribution. When it turns red turn off the flame and then using tweezers put the ring in the water and then pickle it.
File off the excess solder so it is only in the gap between edges. Then put it on the mandrel and gently tap the bottom edge whilst moving the ring around. Take the ring off and put it back on the other way around and tap the bottom in the same way. If you didn’t turn it around you with end up with a ring with one side narrower than the other.
It is also possible to create a D shaped ring and to slightly increase and decrease the ring size.
The ring should then be sanded down going through the various grades and then polished for around 30 minutes.