Jewelry, Gems, & Minerals/Soldering wide 18k rose gold band
QUESTION: Hi Thomas - I have a customer wanting a cathedral style 10mm wide 18k rose gold ring with a 10mm round center stone setting inset so that gemstone top is even with top of cathedral sides of the ring. I have read a lot of horror stories about problems soldering 18k rose gold due to percentage of gold & copper. I've read it can crack easily if not quenched almost immediately and to use alcohol to quench to keep from cracking solder joint and or the band. I haven't been able to find CF 18k rose gold solder or any rose gold solder that is cadmium free. I have only been able to find medium 18k rose gold solder (plumb and regular). I need to make several solders, to make shank and then setting and then attach the two. When soldering gold or silver I use various solders from hard to easy to do multiple solders with my torch. How would you recommend I solder this project with only medium 18k rose gold solder. I haven't found 14k rose gold in any other temper than medium, either. Really afraid of multiple solders could either crack the band or not work because I have to heat to same heat each time and afraid of loosing rose gold coloring. I'm using 10x1mm flat 18k rose gold wire to make shank, one solid piece. Then, was going to solder hand made setting into shank with round 18k wire.
ANSWER: Dear Lesa,
I appreciate your question. Please feel free to get back with me if any of the answer needs clarification or you need the answer expanded in some way.
Copper is a culprit in both making soldering difficult due to heavy oxidation and in promotion of brittleness in alloys with gold. 18k rose gold is heavy in copper, often near 25% copper content with some trace metals. Improper cooling allows the metal to form segregated “islands” and the desired uniform blending may not be present.
I find use of a paste flux such as Handy Flux™ provided good solder flow but does require a quite warm pickle bath to remove flux residue. See this flux here:
Quenching from low red heat in alcohol will help prevent heat shock cracking while cooling the metal quickly enough to generally prevent brittle structure formation in the copper and gold mix.
Look for solders here:
samples, contact for tech advice. This company is very willing to provide advice on use of their products.
You will not find rose solder in all heat ranges but color of the solder is a concern, Precious Metals West will willingly provide sample snippets of solders for you to try and see how it fits your project. If you have questions about their products, do contact the company. You may try by phone and ask for Daniel Ballard. He is helpful and friendly.
I would choose a plumb solder closest to the color of the metal being used and try to use that same solder for the whole job. This does take more heat control than using hard-med-easy for a project but helps prevent problems should you need to go back and solder again or add to a joint done already.
You might try a test sample of the 14k rose solder which is a different temp than the 18k solder and compare for color integrity in the solder joint. If the setting is going to be on a peg into the shank, medium solder should be quite suitable and color match will not be a great issue with so little solder area to show.
Is your fear of losing the rose color from using lower karat solder or some other reason? You do not loose color from reheating the metal but mismatched solder colors may show over time, more so in large joints such as across the shank for sizing, etc. For large joints, try to stick with a solder most closely matched to the stock metal being used, generally 18k solder for 18k gold stock.
Hint: Once the stone seat is cut, you may heat the prong tips to a very low red heat and quench in the alcohol. This annealing will make the tips easier to work and help alleviate any residual brittleness in the metal.
Lesa, another resource is "tips from the jewelers bench" at the top of the page for the Ganoksin website: http://www.ganoksin.com/orchid/archive/
Search for rose gold, soldering rose gold, etc. Different jewelers may have different experiences and recommendations as shown in these archives from a world wide forum.
There is nothing like being there but, alas, I am not there. I believe my recommendations and assistance you may find through contact with Precious Metals West and the archives mentioned previously will get you through construction of the ring.
God Bless and Peace. Thomas.
Please let me know if the answer is helpful to you.
---------- FOLLOW-UP ----------
QUESTION: Thomas - your answer is such a blessing, thank you! My comment about loosing the color is in regards that I read repeatedly heating any rose gold can cause the loss of color. I'm thinking I also read it was due to using the wrong kind of flux. The flux didn't last long enough to protect the gold and when they sanded/polished it it was more yellow than rose gold! I do have the flux you suggested from Rio grande. I have to thin it a lot using their self pickling flux, My-T flux, because it very quickly becomes a cake of solid flux! Do you recommend using the self pickling flux to slightly thin the handy flux if it's too thick for this project or would you get a new bottle that wasn't as thick?
My last question is concerning my torch. My work bench is in my home. I was told several years ago by another expert jeweler that it was not safe to have a smith torch with propane and oxygen containers in my home. So I have always used a refillable propane torch. The flame is adjustable but not as focused as using a smith torch. Thus the reason I use various temps of solder. I 'm pretty certain, though I will do a test, that it can get hot enough to flow the solder. I'm just wondering if you think a refillable torch will be focused enough to solder multiple times with one temp 18k plumb rose gold medium solder? The other question is do you think having the smith torch with the fuel containers in my home is too great of a hazard? I've really wanted a smith torch but really didn't want to put my home/family in danger!
Your previous answer really helped explain the copper issue and how to avoid a disaster! Thank you so much for your assistance time it takes to reply to my post!
The local fire codes and what the fire department inspectors look for is that extinguishers are handy, that oxygen is secured and that propane kept inside be no larger than the disposable bottles of fuel gas. Grill sized or larger propane is not allowed inside. The little torch or Meco will oxygen will certainly get enough heat, however I am not sure of the gas connections for the small disposable propane bottles or how long the small screw valve bottles would last. A basic regulator would be needed. A stand or cart might be needed to keep all tidy and in place.
In your situation,I would recommend natural gas. It gets hot enough and is not so much of a concern for leaks as propane. If you believe propane will do better, get a small portable bottle as used with camping lights and small portable grills. Stay away from outdoor gas grill sized propane for using inside. Those bottles contain too much gas should there be a problem or leak.
Having good heat control is one of the most vital aspects of good soldering work. To gain such control, the torch should not be struggling to provide adequate heat. In fact, a decent torch providing more heat than you need is the way to go. You simply control the heat and type of flame by regulating the flame size and the mix of oxygen and fuel gas. Write again with you concerns. I still have some info for you bit it is not quite ready...crashed computer and trying to get going again after new Windows installation. Yikes!
God Bless and Peace. Thomas.