Tips

SAWING TIPS:
Working on jewellery, whether repairing or creating a new piece, is no different. A bench jeweler must perform basic skills with precision in order to create excellent work - Skills such a sawing, filing, soldering, and polishing need to be mastered. For the apprentice jeweler, these articles will lay the foundation upon which the skills of the trade can be built. For the rest, these articles will serve as an important review. At the jeweler's bench, even the most complicated task is a compilation of basic skills performed with precision and accuracy. Because of this it is advantages for all jewelers even the most advanced to review and practice the basics.

The jeweler's saw is one of the most widely used tools at the jeweler's bench. In the hands of a skilled craftsman, a saw can produce the most intricate patterns or accurate straight lines. It is also used as a file in small areas inaccessible by other tools. It is important for a bench jeweler to master the skills of sawing to perform quality workmanship. These skills are not difficult. However, to achieve precision practice of correct mechanics is required.

To begin cutting, place the metal on the bench pin. Hold it firmly; if the metal slips the blade will break. Rest the saw blade against its edge; gently draw the blade downward. The blade should begin to cut. If it does not, check the blade. It maybe the wrong size for the metal being cut or it maybe installed upside down. The teeth should point down towards the handle, cutting on the down stroke. If the teeth point upwards, remove the blade and turn it around.

Continue with a slow steady up and down rhythm using the entire length of the blade. This will allow you to saw faster and more accurately. Short choppy strokes result in uneven sawing and will prematurely wear out that section of the blade, causing it to break. On the downward stroke, a natural forward movement provides sufficient pressure on the blade. Too little pressure allows the teeth to simply scrape the metal, which is ineffective. An excess of forward or downward pressure will cause the blade to break.

Release the forward pressure on the upward return stroke. It only repositions the blade for the next downward cutting stroke. Dragging the teeth on the up stroke can cause the blade to misshape and the teeth to wear unevenly.

Saw in front of your body in a forward direction. Some jewelers keep the saw in one forward position and move the metal into the saw. Others hold the metal steady and move the saw in the desired direction. Still others move both the metal and saw as necessary. With a little practice, you will develop the most natural method for you.

Sawing is most efficient when remaining relaxed while sawing. Tensing muscles in the hand, arm or shoulders cause fatigue and cramping. In addition, un-satisfactory sawing will result. The arm and shoulder should be loose and the hand remaining relaxed. If necessary, adjust your chair or body position in order to be comfortable and relaxed while sawing.

Always saw on the waste side of the line. Cut as close to the line as possible without cutting into it. It is always better to leave too much metal, which can be removed later, than to cut away too much metal. With experience, you will be able to cut right along the line with no additional clean up needed when finished.

As you saw, blow away metal filings that accumulate. Then the cutting line remains visible for more accurate cutting. Always pull the lap tray out beneath the bench pin. This will catch the filings from sawing. Collect them and send them to a refiner for recovery.

To saw a straight line, tilt the saw forward slightly. Then the cut already made will help guide the blade, and it is easier to sight the straight line along the blade.

To saw curves, keep the blade perpendicular to the metal. Tilting the saw forward while rounding a curve will pinch the blade causing it to break prematurely.

To make a sharp turn, continue the same up and down rhythm without any forward pressure. Then slowly rotate the metal around the moving blade. On each downward stroke, make a slight sideways cut until you reach the new direction.

Saw blades do wear out. When teeth are dulled to the point where extra force must be used in cutting, it is best to replace the blade. Extra pressure decreases control; therefore nothing is gained by this economy.

Often saw blades break before they wear out, a wasteful situation. This can be avoided or at least minimized with proper sawing procedures. The two main reasons for blades breaking are too much force used while sawing, and pinching the blade from twisting either the metal or the saw frame.

DO NOT throw broken or worn out blades away. Particles of gold become lodged in the teeth during use. Place all old saw blades in the container with the used polishing machine filters to be refined. A good refiner can reclaim this gold.

An excellent practice exercise is to cut out coins. Drill a hole in the background area and thread the saw blade through. Cut around the profile of the figure on the coin. Then saw around the inside of the edge of the coin, forming a frame around the head.

Precise sawing is important. It saves both metal and time. When you perform accurate sawing very little, if any filing is needed. Following these basic procedures and with a little practice, one can easily master the art of using the jeweler's saw.

SAFETY WHEN POLISHING:

Safety is the first and most important aspect of working in a workshop environment, and a polishing wheel revolving at a high speed is certainly a focal point of danger. Anyone taking his or her first steps in polishing should always receive clear verbal guidance from an experienced colleague or instructor. Ideally aprons or overalls should be worn without any loose material likely to become entangled in the revolving wheel. Long hair should be contained in a cap, hairnet or similar apparel.

Although not always popular we would also recommend using protection glasses or goggles and a facemask to avoid the small pieces of calicos and other fibers that leave the revolving wheel. The facemask will also offer protection to your nasal passages especially if polishing for a long period.

An efficient extractor unit with a protective hood/cowl should be part of your polishing set up. This will assist with the removal of airborne particles and give protection from inhalation and ocular damage. In addition, should your grip on the article being polished be lost, the hood/cowl will also serve as a useful barrier and lessen the chance and velocity of a work piece flying across the workshop.

DUST MASKS & STEAMED UP GLASSES
As the awareness of possible hazards with fumes and metal dust in the workshop grows, more jewelers are wearing facemasks. This can cause a problem if you also wear glasses, as the lenses are inclined to steam up.
The key to clear vision is to ensure that the mask is closely fitting and doesn't allow moist air to escape over the top of the mask. Some masks have a flexible strip along the top, which can be adjusted to the contours of your face. If your mask doesn't have an adjustable strip, use some non-irritating surgical tape to help seal it closer to your face: this will also help to stop the mask from slipping as you work.

CARE OF MICRO MOTOR HAND PIECES

Often in constant use in a busy workshop, the following notes will help you obtain long trouble free use of a vital everyday tool.

1. Always ensure the spindle on the fraizer (burr) is clean and smooth.

2. Regularly clean and lubricate the holding jaws and front cone by disassembling and thoroughly cleaning them as well as the thread, inside and axle. When reassembling lubricate with good quality fine oil. Cleaning can be done in an ultrasonic tank with the exception of the bearings.

CASTING TIPS:

Q. Where is the best place to attach a sprue?

A. Generally one should always attach the sprue to the section of the pattern, which has the greatest mass. Close attention to the size and position of the sprue will pay dividends, avoiding extra cost and time when you are cleaning up after production. Good sprue positioning takes time and experience, copying what has worked before on similar patterns will often produce the right results

Q. Why do castings have a poor surface finish?

A. What was the original like? The surface finish on a hand carved wax master pattern can often be improved by rubbing it with a cloth dampened by white spirit. Although most metal master patterns will produce good results if the surface is highly polished, some brass or alloys of high copper content are better if plated with some other metal.

Q. What are the main differences between vulcanized rubber moulds and cold cured moulds?

A. With cold cured rubber moulds one can mould more delicate and fragile patterns. It also has a lower shrinkage performance. The main disadvantage is its' higher cost and shorter working life when compared to vulcanized rubber moulds.

SOLDERING PLATINUM:

Getting your solder to 'stick' in the right place when working with platinum can be a problem, since using a flux can cause blemishes and using a solder pick can contaminate the solder or cause oxidation if you move the heat away when initially applying the solder.

Although it may not sound appealing a little spit will work just as well as flux to stick solder to the joint, or indeed plain water. Both will simply evaporate as the solder starts to melt, eliminating the potential contamination of the metal at the joint.

As an alternative, you can also wait to place your solder until the joint has been heated to red-hot. Because red-hot platinum is somewhat 'sticky' solder placed on the platinum should stay put until it melts.

If the solder is cold when it's placed on the joint and then heated, there should not be any problems with oxidation.

SOLDERS:

When you first buy a new panel or stick of solder, colour code it.

Use a permanent marker pen to completely cover it both sides, red for hard, black for medium, blue for easy.

Then, when you cut off the snippets/palings, you can easily identify their melting temperatures, as well as locating them if they drop on to your bench tray. The ink will disappear without trace when heated during soldering.

PREPARING GRAVERS

Before any graver can be used it must be sized, sharpened, shaped and fitted into a graver handle.

1. Fit the graver into the handle. Some graver handles will need to be drilled; a 4.5mm drill will be suitable for graver handles.

2. Place the handle with the fitted graver into the palm of your hand and grip the graver between your thumb and index finger and mark the graver 10mm beyond your index finger. Remove the graver from the handle and tightly fix it into a vice, point upwards and the mark level with the vice jaws. Strike the graver tip smartly with a steel hammer, snapping off the excess length.

3. Your graver is now ready for sharpening. To create the point you may need to remove an appreciable amount of metal. This should be done slowly, initially on a grinding wheel, taking the necessary safety precautions and finishing on a carborundum stone. Your cutting face should be ground to 45° and it is normal practice to reduce the height of the cutting face for better visibility. Overheating the graver when grinding or sharpening will draw the temper of the metal and should be avoided at all costs.

MELTING TIP:
When melting in clay or salamander crucibles it is important to add a pinch of borax or potassium nitrate (salt petre) This eliminates surface oxidization and slightly raises the alloy's melting point.

RING SIZING TIP:
Before sizing a ring, check to see if there is a join in the shank
This may be a weak point and could snap if stretched. Cast rings could also snap if stretched on stretching equipment, especially where porosity exists.
The safest method for enlarging cast rings, (especially if you need to enlarge them to more than one size), is to use a roller type gem sizer, or to anneal the ring before stretching. I prefer cutting the ring on the original join at the bottom, opening it up and soldering a piece of the same metal into the gap. One size is normally 0ne millimeter or so, check on your size stick before soldering. Be careful of the stones in the ring. Most stones can not handle any heat and should be covered with heat paste or soggy cotton wool halfway down the ring. I would suggest that you clean all rings set with stones before applying heat because any dirt, hand creams etc. will burn onto the stones and is very difficult to clean afterwards.