Processing 14K gold solder

[oldtimmer]

Can I process 14K gold solder the same way as you would regular 14K gold?

I have about 15dwt that I had planned to sale, but the wife does not want me to sell it and take the loss that I will do by selling. She has seen me recover gold foil from e-scrap and thinks that it is just as easy. I have tried to explain that the process is not as easy and is not the same. Should I expect the same yield as if it were 14K gold from jewelry. I already have some silver that I can use to inquart with.

 

[qst42know]

Do you know the grade of solder? The price of gold or silver brazing alloys are much higher than the cost of the metals they contain. A Jeweler may be willing to pay for a known alloy.

This was clipped from the web. They are color matched for the "K" markings. And the Easy Medium and Hard are different melt points for successive assembly steps. Hard would be the highest PM content and melt at the highest temp. It would be used first in a complex assembly so that each additional braze wouldn't melt the one before.

"Handy & Harman’s karat gold solders are supplied in the follow­ing karat designations: 6, 8, 10, 12, 14, 16,18 and 19. Both yellow and white colors are available in the various karat groups, as well as three application levels-Easy Medium and Hard. Their gold con­tent ranges from approximately 25% to 80%, and their fine silver content from 2.5% to 58%."

 

[oldtimmer]

The two big pieces are 14K soft (easy) and the other is 14K hard. They weigh around 6.5dwt each. There are two smaller pieces, one of 14K and one of 10K, unknown other than the karet marings that are stamped on them.

And yes, I visited our family jeweler to see if he was interested in them. I was offered an insulting $10.00 per DWT for them. One other jeweler was not interested in them. I have ad them in a safe since the early 1970's when I was doing a lot of gold and silversmithing. I had forgotten about them until I was cleaning out my safe. I als have around 60 oz. of melted down silver contacts from switches that I need to find the time to process.

 

[qst42know]

Your jeweler may regret his offer when he needs to buy more.

Anyhow a soak in nitric should be a good place to start. It may have little effect on the hard 14k.

Others here will have much more experience with brazing alloys.

 

[Harold_V]

If the silver contacts you have are easily melted with a torch, use some of them to inquart the solder and go for it. Shoot for 25% gold content for the inquartation. Recover the silver after the initial digest in dilute nitric acid, using scrap copper. That way processing the silver is a freebie---you must use something----it may as well be contacts.

If the contacts are the large type used in large electrical apparatus, they may be alloyed with other constituents. Small contacts tend to be alloyed with cadmium, or they may even be high purity silver. Not sure about that, but they will serve perfectly well for inquarting.

Harold

 

[goldsilverpro]

I have run many lots of large contacts that had been sweated off of copper buss. Most every lot I ran contained some cadmium. Whether the Cd was in the points or the silver solder, I'm not sure, but I think it was in the solder. The lots I ran were of at least 5#, so they contained a large number of points. Maybe only a few contained Cd, but that was enough to scare me into not melting them directly. I always dissolved the points and cemented the silver with copper before melting.

 

[qst42know]

There was a time when cadmium was not an issue. It does have a profound effect on melt point and flow characteristics of brazing alloys. What worked best was what was used in any and all industries. The hazards and long term effects were either not known or flat ignored. Asbestos, R-12, cadmium, trichloroethane, PCB, cyanide, to name a few.

 

[Harold_V]

but that was enough to scare me into not melting them directly.

I'm guilty of thinking everyone uses a setup like I had. I did all my (torch)melting in the hood, so I wasn't subjected to the fumes.

I recall running one small batch of contacts that were not removed by torch----that yielded a small percentage of silver as compared to the starting weight. I attributed the loss to cadmium, but I also had no way of determining its presence. Did you have a fast and easy test for the stuff?

Harold