Fabricating a Platinum Mounting

Brad Simon

 

To begin making this mounting we make the under bezels for the three center stones.  This piece of platinum is 1.2 mm thick and is just a little narrower than the two side stones are wide.  We mark off the length of the stone and cut about halfway into the platinum stock.  Then mark for the second stone and again saw in about halfway into the platinum stock.  We don't want to cut all the way through it this time because the extra length of the stock makes it easier to hold. 

 

Lay the diamond table down onto the platinum to make sure that the marks are correct.  We want the platinum square to be just slightly smaller than the diamond.  Next, set the dividers to 1 mm and scribe a line all the way around all four sides of both of the squares.  Then drill a hole through the platinum and thread your saw blade through it and saw out the inside of each of the squares.  Saw right up to, but not cutting into, the scribed line.  Use a small square needle file to clean up the holes.   

Lay the diamonds on top to make sure you have the correct size.  At this point we can finish sawing through and cut the two squares apart and the under-bezels for the two side princess cuts are finished.  Repeat the process to make the under bezel for the center stone.  Lay out all three under bezels together next to the diamonds to make sure the lengths are correct.  It is always better to keep checking your work as you progress along, as it is easier to make a change now.

Next file the sides at a slight angle to form the curved top to the ring.  File opposite sides of the center under bezel, and one side on each of the side under bezels. 

Then clamp two of the under bezels together and use 1500 platinum solder to weld them together.  When cooled, clamp the other under bezel for the other side stone to the opposite side of the center under bezel and solder it on.  One advantage of working with platinum is that we can use 1500 solder on both sides and even though the solder joints are fairly close together the heat will not travel through the platinum and cause us any of the problems we would have if this was gold.

Next we need to make the crowns for the two tapered baguettes.  First select a piece of platinum 1.5 mm thick and as wide as the widest end of the tapered baguettes.  Mark the length of the first baguette and then saw part way into the platinum stock.  Then cut from the sides to the depth of the narrow end of the baguette.

File the taper onto the end of the stock and then check with the diamond to make sure you have the right angle and have filed far enough.  Then file the taper for the second baguette.  Once we have the shape filed correctly, set your dividers to 1 millimeter and again mark off 1 mm sides all the way around the platinum. 

Next drill a hole in each under bezel.  I like using the point of the graver to mark the platinum before I drill rather than using a center punch.  It is less cumbersome for me and the gravers are near by and easy to use.  When you drill the platinum make sure to use plenty of lubricant on the drill bit and use a slow speed.  You do not want to drill too fast because that will cause the drill bit to overheat and possibly break or damage the bit. 

Then feed a saw blade through the hole and cut out the center of the under bezels for the tapered baguettes.  Use the saw blade as a file and clean-up along the sides of the cutout.

Once the center is cut out of the under bezels you can then cut them apart.  Be sure to use lots of lubricants on your saw blade.  Cutting a little notch in the side of the bench pin will help hold the metal stock making it easier to hold it still while you're sawing. 

Then cut two pieces of 1 millimeter square platinum wire, a little longer than the widest part of the baguette.  Clamp them with tungsten tipped tweezers.  We can hold our two pieces together between the jaws of the tweezers and place the 1500 platinum solder in place and solder right between the jaws of the tweezers.  The tungsten tips will not contaminate the platinum so we can just solder directly in the tweezers.  Solder one side and turn the tweezers over to solder the other side.  Repeat the process on the other baguette crown.

Next, file the square wire down so that it is even with the sides of the crown.  File the end of the crown smooth and at an angle to fit against the under bezels for the center crowns to continue the curve around the top of the ring.  Clean up the under bezels and the baguette crowns.  Use 320 grit emery paper to remove the file marks.

Then solder the baguette crowns to the three center under bezels.  Clamp the center crown under bezels and one of the baguette crowns and solder together using 1500 solder.  Then repeat the process on the other side.

 

Fabricating a Platinum Mounting continued