How to Solder Rough Diamonds into a New Sterling Silver Ring

Question
Hi Thomas,

I have received a custom order for a sterling silver engagement ring. The client is very specific in requesting I use four roughly square 2mm rough cut diamonds that are already bezel set on ring bands. The stones are so tiny and the shapes so irregular that it would be a nightmare to take them out of the settings, make entirely new ones and reset the stones in the new ring. Can I cut the stones off in their bezels and solder the bezels with the diamonds in them onto a sterling silver band. The diamonds look extremely rough so I'm not worried about damage to clarity (they just look like pieces of grey scratched glass, really)but am worried about cracking or exploding the stone. Is this possible? I read another posting where you said the heat for gold solder would be low enough to not damage the diamonds but what about silver? (these rings honestly look as though they were made in Thailand and imported, not handmade here as claimed by the seller)

Any guidance is much appreciated!
Lori

Answer
Dear Lori,

I appreciate questions from jewelers.  My answer must be general since I cannot see the diamonds and how safe soldering heat would be.  My first consideration would be to talk to the customer about the situation.  There is nothing wrong in letting the customer know your concerns and the why of it all. Unfortunately, the customer appears to believe this is a special custom item and now wants another custom ring...this time a true custom work.

I believe the bezels may be soldered using the lowest temperature silver solder you have or can get. I do not like to use easy or extra easy on work like this because it tends to run sometimes and is not as strong as harder solders. Still, there should be enough contact surface for easy or extra easy silver solder to be perfectly safe in this connection of bezel to band.

The diamonds should not explode. A gas pocket in a stone could cause a fracture but otherwise exploding is very unlikely.  Examine the stones as well as possible with the best magnification you have and back light if there is an opening in the back of the bezel.

With diamonds like this, the situation to avoid is heat shock.  Sudden change in heat from cold to quite hot or quenching can certainly damage many stones and sometimes diamonds.  Play the heat around the band to heat it all generally  to start. Silver will be hot all over when soldered anyway but this will allow a slightly more delicate rise in heat to the diamonds. Run the heat around the bezel to flow the solder, coming almost straight down but not directly on the stones.  When all has flowed, allow to air cool. Do not even consider quenching to cool these rough stones.

Do you use a solder pick? This is a rod of tungsten or stainless steel of about 1mm+ thick and put into a wood handle to keep your fingers from the heat. About 3.5 inches long works fine. Taper the end to a dull point.  When soldering, be sure the silver is covered with boric acid by dipping in a boric acid/denatured alcohol mix (stirred up first) putting the flame to the ring and allowing the alcohol to burn off. Put flux in place for the bezel(s) and put one in place. Start to heat the ring and then move the flame to the motion around the bezel.  Take the solder pick and put a little flux on the point and heat to make the flux sticky. Be fast and touch this to a ball of the easy silver solder. With the bead of solder on the point, keep the flame going and move the solder ball to the edge of the bezel, touching both band and bezel. Scoot it as needed with the point of the pick if the solder moves or to realign the bezel..  When hot enough, the solder will melt and run around the bezel.  If you use a solder pick you already know all this. If not, give it a practice on something else and if comfortable use this method with the ring you are making.

If the bezel is fitted prior to soldering so it will not move, you can simply put the solder touching both bezel and band and heat to get good flow. If it tends to jump to either bezel or band, touch the point of the bezel to the solder and the line between the band and bezel and move it along the joint to help the solder flow where it is supposed to go.


I believe the diamonds will be ok but do suggest you mention risks to the customer. You don't want someone saying,"Why didn't you tell me that could happen"?  I believe it will do fine just so you heat gently and do not quench. Still, speak to the customer first.

Lori, Best wishes with the ring!  God Bless and Peace. Thomas.