Best Practices: Platinum Tools and How to Avoid Contamination
Quality Assurance Benchmarks highlight workmanship of semi-finished and finished jewellery. Learn best practices for working with platinum tools, including how to avoid contamination.
Working with platinum is different to working with silver and white gold. Platinum is easily contaminated, so working with it requires a clean environment and, in some cases, dedicated tools.
Keeping dedicated tools for platinum work will reduce set-up time and make performance of repair services, alterations and custom orders more efficient
Gold filings that come into contact with platinum are a major contamination source. For example, when gold filings are on a platinum surface that is heated to platinum-soldering temperatures, the gold will leach into the platinum and leave visible traces that cannot be removed by polishing. Contamination from excess gold, silver or other non-platinum metals can also lead to melting of the platinum piece during the soldering process.
A good practice is to have a dedicated container for storing platinum tools when they are not in use. Here the bench jeweller is using a metal cup to hold platinum-dedicated tweezers and files.
Use dedicated solder containers. It is bad practice to cut solder and place it on a soldering board. This practice picks up debris that will contaminate a platinum piece.
Note that the jeweller is using a flat bench pin that is only used for working with platinum
Save time by using dedicated and commonly used or favourite pliers for platinum working
Tools for Working with Platinum
Clean all surfaces, tools, bench pins and other areas where gold filings might be before starting platinum work. One common contamination source is filings on the ring mandrel. Be sure to include it in the cleaning process before starting a platinum repair or alteration.
Be sure to use a dedicated bench brush for platinum, and not one used on other precious metals. Natural brushes, like the one on top, have soft bristles and will not scratch platinum.
Working with platinum becomes problematic when it is contaminated. To reduce potential contamination from other metals or bench debris, consider creating dedicated platinum-tipped tweezers for this work.
This pair of steel tweezers has heavy rectangular platinum wires riveted to each end. This modification was made by the jeweller, and is ideal for handling platinum when soldering.
These tweezers are made from non-magnetic stainless steel. The slide lock is made from copper wire and helps secure items in the tweezers.
Platinum emits intensely bright light when heated to soldering and welding temperatures. Eye protection must be worn at these times.
This welding lens is a shade no. 7. When using platinum solders of 1700° C or more, use this lens. For lower melting point platinum solders, you can use a shade no. 5 lens.
Magnets have been glued onto the lens. This custom application simplifies the use of the dark welding lens in combination with common jeweller optics.
The supplier-provided plastic mounting tabs securing the magnification have been replaced with steel screws. The magnets mounted on the lens will securely attach it to the optics, simultaneously magnifying the object and protecting the eye.
Keep a magnet in a platinum kit to distinguish platinum cobalt from other platinum alloys
Use dedicated files for platinum. If other precious metals become embedded in a file’s surface, they may dislodge and become ingrained in the platinum.
Use vibration from the hammer handpiece to check for loose stones after sizing. Place the tip of the hammer handpiece over the bulge of solder at the joint on the bottom of the ring.
Run the hammer at a moderate speed and watch for stones in the mounting to jiggle. Tighten loose stones as needed.
Clean the tip of the hammer handpiece, and remove fragments of non-platinum precious metals.
A dedicated ring clamp is highly recommended
Place regular bond paper over the stretching device in a wrapped pattern. Tool marks potentially lead to excessive removal of platinum. Remove them whenever possible when working with platinum.
Clean the stretcher before using
Tools for Pre-finishing, Polishing and Buffing Platinum
This tray contains dedicated platinum polishing and buffing compounds in various grits, along with assorted wheels and brushes for performing finishing work at the bench
Each compartment in the tray contains attachments dedicated to specific platinum polishing and buffing compounds. Consistent use, as well as cleaning of processed products between steps, eliminates the potential for cross-contamination. This is also an efficient way to improve platinum’s finish and lustre.
These Japanese platinum polishing and buffing compounds are evenly blended and have excellent adherence to buffs, brushes and felt attachments. The same compounds, with larger wheels and attachments, are also used at the polishing machine for platinum.
Dedicate all polishing points, wheels and brushes for platinum use at the bench and polishing machines
Small polishing points and wheels come in a variety of shapes and sizes. Here, a hard cone-shaped wheel and platinum polishing compound are used to polish the inside of a platinum setting.
Abrasive sponges come in a wide variety of grits. They are ideal for platinum, as they take the shape of the item being worked.
Rotary burnishers are ideal for platinum. This rotary burnisher is being used to smooth the area where the post from the peg setting protruded into the inside of the ring shank.
Be sure to keep rotary burnishers clean and/or dedicated to platinum
Attach abrasives to wooden sticks, file faces or other flat surfaces that provide the best contact with the piece being pre-finished
Here the abrasive surface is attached to only one surface. Attaching it to two surfaces of the same stick often causes unwanted metal removal from adjoining surfaces – in this case, the adjacent prongs.
This file has fine adhesive paper stuck to the surface
The shape of the file makes access to small and tight areas possible, as shown on this platinum setting
Micro-finishing film is a fast-cutting abrasive that provides precise, uniform, close-tolerance finishes. The abrasive is resin bonded to a polyester film backing, and contains micron-graded mineral particles that are electrostatically and consistently oriented.
This film is ideal for abrasive work on platinum because it can be custom fitted and adhered to a variety of tools and shapes for a wide range of applications. Micro-finishing film can be used wet or dry, has a plain or adhesive backing, and is available in a range of grits, from a coarse 180 grit to a very fine 1200 grit.
Micro-finishing film is available in sheets, strips and other shapes. Here it is attached to sanding sticks and labelled for progressive abrasive use.
Tools for Soldering Platinum
A high-heat soldering block made of alumina, ceramic or other high-heat material is required for platinum. Do not use charcoal. This one is made of alumina.
Platinum requires a high-capacity torch and a tip with a single cone outlet
Do not use flux or firecoat when soldering platinum unless diamonds are present. Cover diamonds with firecoat (denatured alcohol and powdered boric acid). Allow it to air dry, and then remove the firecoat from the platinum.
Use natural gas, propane or hydrogen fuel with oxygen. Do not use acetylene gas.
This soldering block is made of dense high-heat ceramic, and is engineered to withstand the heat required for platinum annealing, soldering and melting