Platinum Guru

Sizing a Platinum Ring Using a Laser

If there is still a gap between the opposing ends of the ring this is not a problem as it will be filled with the laser.  If the ring was being soldered this gap would have to be closed.

With a small beam setting and the voltage set to 300V, take your first shots at the ring.  These will deeply penetrate the metal and stitch the two sides of the ring together.  Turn the ring all the way around as subsequent shots are fired, welding the two ends together and leaving a welded trough.

Once the ring is welded together, some additional wire is needed to fill the trough that the initial weld left behind.  This is done by melting small amounts of 0.2 mm round wire, of the same platinum alloy as the ring, into the groove.

Widen the beam to flatten the extra molten metal along the groove.  Do this by overlapping the laser shots to create flat metal puddles along the surface.

During the welding of the inside seam, the edge of the ring, which is quite thin, may begin to melt inwards as the laser follows its contour.  If this happens, add more of the 0.2 mm wire to that edge to straighten out the line.  You can use the same laser settings.

   ~Jurgen

Laser Welders,Ring Sizing,Platinum Jewelry

Sizing a Platinum/Cobalt Ring

Pt/Co is slightly magnetic and you can easily detect it at the bench with a magnet.

Sizing a Platinum ring is normally done with the welding method as long as there are no stones nearby.  The exception is Pt/Co, as cobalt oxidizes.  To size a Pt/Co ring, 1700 seamless solder is recommended.

Roll the solder paper-thin, wedge it into a very well fitting seam and heat.  The seam should be very, very thin.  When welded with a torch, Pt/Co may oxidize slightly.  This can be removed by firecoating the object after the initial welding and re-heating it to about 1000 F. or by pickling in a 10% solution of nitric acid.  The oxidation will not reappear during wear. 

Next, use a file to remove excess solder, and burnish the seam with a Tungsten burnisher.  This should remove all traces of the seam.  Now polish and clean the ring.  With its good hardness, Pt/Co takes on a great polish.

  ~Jurgen

Sizing Rings,Platinum Jewelry,Bench Jeweler

Gold Contamination In Platinum

Sometimes when annealing platinum it is possible to contaminate the platinum with other metals.  Some filings, or solder chips on a soldering surface, or any other metal on the bench can be melted into platinum thus contaminating the area.  With a ball burr, grind out the contamination; similar to the way a dentist cleans a cavity.  Now take a small piece of the same platinum alloy the object is made of and weld it to fill the hole.  Filing the excess metal away, you create an invisible repair.

To prevent this contamination from happening in the first place, soak your platinum in a 10% solution of Nitric acid for about 10 minutes, before annealing, welding or soldering.

~ Jurgen

Platinum Jewelry,Fabrication,Casting

Jewelers Tools for Soldering Platinum

Additional tools needed on your jewelers bench for soldering platinum include: a high temperature soldering board; tungsten carbide or ceramic tip tweezers; and a tungsten solder pick.  When not in use, remove the solder pad from your jewelry bench to prevent filings, grindings, polishing compounds, and other contaminant from gathering on it.

 

Brad

Jewelers Tools,Platinum Jewelry,Soldering Platinum

Platinum Solder Seams

When soldering platinum, make certain you have a tight seam.  When polishing, solder will pull out of a solder seam from platinum more than from gold.  This makes having a precise fit extremely important.

 

Brad

Platinum Jewelry,Soldering Platinum,Jewelry Making