Fusing/soldering silver with a kiln

I am a retired data manager who has been learning silversmithing (and now a bit of goldsmithing) for the last few years as mostly a hobby. Actually, cloisonné is my favorite thing. But as someone who has been managing NASA/NOAA/USGS Earth science data for decades I am really trying for a de-carbonized life (yes, climate change is real - the data is publicly available if you need to prove it to yourself). That means that I’d like to get rid of torch work as much as possible. As someone who already has a nice fast kiln (powered by my solar arrays) I am thinking that it should be possible to solder/fuse silver, mostly sterling and Argentium sterling with it; but I haven’t found videos, etc. on Google about that. Is anyone here doing that? Got any pointers? Any classes/workshops/people to recommend?

Before bottled oxygen, before compressed gas, before the invention of solder, ancient goldsmiths used eutectic soldering to join their work over a charcoal brazier. Adapting the techniques to an electric kiln should take only a bit of experimentation.
Eutecitic soldering is most well known as being the technique used for granulation, but it can be used for any joint in a noble metal. Keep in mind, it works best with purer metals, as the lower the melting point of the alloy the more difficult to get a joint before the whole thing slumps. So having a setup that can tightly control the temperature in the kiln will be critical.

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Nothing at all wrong with using the kiln powered by solar energy, but it is probably not suitable for all jewelry tasks…how about a water torch? Or possibly a small alcohol burner with a blowpipe. I’ve used the latter for soldering small chain links and it works quite well. I think the blowpipe and the burner were both under $10 each. IDK how you will determine that the alcohol is distilled from plants, tho’. -royjohn

What an interesting question you have presented! As folks have stated soldering and fusing has been done in charcoal or coal fire and various kilns for thousands of years. So yes, you can do what you’re suggesting, but you’ll be charting your own path as it’s not a common way to go these days.

You asked about classes, my advice is to research granulation and mokume gane.

For granulation, Ronda Coryel is fantastic resource, especially with Argentium granulation. www.rondacoryelldesigns.com

Ronda teaches a bunch of workshops all over the place and also has quite a number of videos available for download on her website.

For mokume gane, Steve Midget is a fantastic resource. Steve wrote an excellent book on mokume gane a number of years ago. At some point he generously decided to make his mokume gane book available as a free download on his website. www.mokume.com

There are others out there, but that’s a good place to start.

Now if you want to solder in your kiln, there are of course a number of issues. It’s going to be like baking something. Not hot enough, it won’t work and too hot you’ll destroy it. You’ll have to experiment with temperature and time.

The hardest part with solder placement is that you won’t be able to control where the solder goes exactly, except to rely on capillary action. (solder wants to flow into a joint). Again, you’ll have to experiment.

For flux, I’d recommend drying out some regular, old, white jewelry paste flux, then grinding it into a powder and shaking it on to your joint with an old pepper shaker or something like that.

I’m pretty sure that soldering is done in a kiln for various commercial purposes, like mass production chain making, but I don’t know how you learn about that? Maybe someone in the forum knows?

I’ve never used them, but some companies sell solder filled jump rings. (like Rio Grande). I’m pretty sure you could solder them in a kiln, but again, I’ve never tried.

As royjohn suggested there are other torches out there, like a water torch (oxygen/hydrogen generator torch). You also could consider pulse arc welding (with an Orion or PUK). Or a laser welder.

I hope all of that helps! Like I said, you’re charting you own path, but it sounds like you enjoy experimenting!!

Best of luck and let us know how it goes!!

Jeff

Good to know and I note that the cloisonne’ kiln I have has quite good temperature control.

Good tip about the water torch, you aren’t the only one who mentioned it and I looked it up. Sounds interesting, though expensive.

The alcohol burner and blowpipe would never have occurred to me, so thanks for mentioning it. As for the alcohol, isn’t that usually distilled from plants? And I suppose, worst comes to worst I could distill my own

I’ve looked at Ronda’s site and some of her videos. Actually since she is only a day’s drive away, I sent her an email to ask about visits, workshops, joint experimentation and such. We’ll see what she says.

As for mokume gane, it took me a while to figure out why you were suggesting that; but once I figured it out I decided that it was a good call. I’ll have to read that book you suggested!

My kiln has a nice quartz window so with proper eye-wear I can watch the process, and yes I expect I’ll burn up some silver to start… but oh well… maybe it will come out looking cool and I’ll want more of it?

I have been thinking about pulse arc welding… Even the low end is rather out of my price range; but I have started saving towards buying something some day. Laser would have to come down a lot in price for me to consider that and my understanding is that it has reflection issues with silver.

In any case, thanks for all the pointers and if I ever figure anything out that works, I’ll let you all know!

Sorry! I was trying to condense my words and not write an overwhelming amount. There’s two ways to do Mokume Gane. Both are potentially helpful for you to know about and to understand. One is with solder, the other is without solder. Both can be done in a kiln. The technology behind both processes is what I’m suggesting that you look at.

As far as soldering in the kiln, timing will be crucial. You’re lucky that you have a good viewing window. Many, if not most kilns, that I’m familiar with don’t that. You’ll have to figure out a plan to get your metal out quickly, once the solder melts. Again the difference between not hot enough and too hot is very small.

And yes, lots of these processes, like laser welders, pulse arc welders, water torches expensive! Plus they have compromises.

One other thing to suggest is to go to a jewelry trade show where all of this equipment is there to look out and to try out in person.

Again, best of luck and keep us posted!!

Jeff

I can see fusing working in a kiln so long as the piece can be removed before it starts to melt. Eutectic soldering is either the same thing or a close relative.

I have tried viewing enameling (not the same thing as fusing) through a kiln window and it wasn’t easy to detect what I was looking for with all that orange light, and there is the issue of infrared radiation and its effect on the eyes. Green glasses are supposed to help with that but make seeing even more difficult.

I have some doubts about kiln soldering, at least in some cases. When I make a bezel setting I will have the bezel rest on a slightly wider base, place the solder around the inside edge of the bezel, heat from below and around the edges. That draws the solder into the joint and gives a nice meniscus on the outside of the bezel. The excess base is sawed / filed away and the join is seamless. If instead the entire piece is evenly heated in a kiln, it seems to me the solder could just as easily climb the wall of the bezel rather than go into the seam, or go only partly into the seam and leave a slight gap around the bezel.

I think there are cases where you want to deliberately draw solder in a specific direction, and I don’t see how even, directionless heating in a kiln would do that. But If it actually does work, please share the positive results.

Good luck with it.

Neil A

Placing a piece to be soldered closer to a heating element, and maybe in a back corner, might give the solder direction by supplying direct heat in addition to evenly surrounding heat.

Neil A

Or you could explore the world of metal clay! Tons easier I would think. If you can imagine it you can create it in metal clay and a kiln is the best tool for firing it.

For a delicate jewelry piece that requires multiple, sequenced soldering, I think it would be difficult to use a kiln. My experience includes jewelry fabrication; I am also an enamelist, cloisonné included. My third love is filigree, which requires intricate and repeated soldering of tiny wires without melting.

From my experience, with cloisonné, you are melting glass, not metal. For each type of enamel, there is a temperature range suitable for melting and fusing the glass, but well beneath the melting point of metal. And, you set the kiln temperature at a specific point, meaning that the piece won’t heat above that point. So you have a significant amount of time to remove the piece without any damage.

With filigree, on the other hand, the amount of heat from the torch and the length of time with the heat on the piece is extremely time sensitive. The filigree wires are tiny, generally twisted 26 or 28 gauge fine silver, attached to a much thicker wire frame, usually at least 18 gauge (1 mm). You need to flow the solder on the filigree wires, simultaneously using enough heat to attach them to the larger frame wires which take longer to heat. I find I am looking for that instantaneous flash of red/silver that occurs when solder is melted, then removing the torch as absolutely fast as possible so that the filigree wires don’t melt… I don’t know how that would translate well in a kiln. Your filigree wires are much smaller and will absorb heat much faster than the frame wires.

It may be that the rate of heat absorption between smaller and larger wires is as important as the set temperature of the kiln. And, there are always safety issues trying to remove a 1200 degree + piece from a kiln quickly without burning yourself.

I’m not an expert on eutectic soldering or fusing; the questions that comes to my mind, given my thoughts on the filigree, is how much is successful fusing dependant on the exact temperature versus the time of application of that temperature?

With very intricate or complex pieces, jewelers may solder them many many times, and with a torch, can pinpoint exactly where the heat goes and how long it stays there. Jewelers often use sequences of solder, from hard to medium to easy, and also, each round of soldering raises the melting point of the former solder joint. I don’t work in argentium silver much, but it acts very differently under heat than sterling silver does and fuses much more easily. People who work extensively with argentium may be able to give you more insight.

Successful soldering in a variety of types of projects, takes a lot of finesse, and to me, that is part of the challenge and the fun of fabrication. I think the choice is choosing which types of projects you want to do: those that can successfully be soldered in a kiln, or those that you choose to do, then decide how to solder.

Marcie Rae

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I too make filigree and it is a real choreography to get everthing going the right way to keep from melting the small filler wires and still get everything soldered with a torch. I suppose that, if you used a kiln, and could slowly ramp up the temperature so that each element of the piece was at the same temperature regardless of its mass, you could solder with a kiln. This also requires great accuracy in your controller. Filigree and granulation have both been a sophisticated art form for 1000s of years, long before our modern torches and kilns. I marvel at how it must have been done long ago…Rob

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I had played with silver clay a few years ago; but at the time the clay was so expensive as compared to regular silver sheet and wire, I didn’t pursue it. Has the price come down since then?

Thanks for the input - I do note that the more I look into it, the more the water torch (hydrogen) or the pulse arc welder seem more appropriate for doing anything other than fusing metals. I am hoping to do a little regular sterling to regular sterling, argentium to sterling, and argentium to argentium testing over the next few weeks. I’ll let you all know how that goes… (but don’t hold your breath as I am still in the midst of writing the last few papers from my pre-retirement life as well)…

As for filigree, the idea of slowly raising the temperature to a set point seems reasonable. From what I’ve been reading that seems like something you can do (the keum boo folks apparently can use a kiln to create their bricks).

But I must admit that the part of jewelry making I like best is the painting with glass (i.e., cloisonne); so anything that can make the actual setting go faster would be preferred by me! And I really like that my solar arrays/batteries make running that kiln pretty-much carbon free!

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Sadly a water torch doesn’t work well with .999 silver and silver alloys. The same with copper. Both are huge heat sinks. The tiny pinpoint flame is really hot but can’t get the body of the work hot enough. If directed at a solder seam it will just boil the solder pallions. A TIG welder would work better. It will necessitate having an argon gas shield.
-Jo

The cost of metal clay is pricey, but I have been using it along with traditional metalsmithing techniques for 27 years. If you are selling your work, just add the additional cost to make to your prices. Trust me, it really doesn’t add that much to the cost to make. Of course, it depends on how you use it.

I learned a little MC, years ago. A friend from enamels courses in colllege went on to have her own teaching studio in both disciplines, but my foray into it was really to avoid learning traditional metals. I do love my little kiln from a PMC biannual meeting she got me to go. A show special. Its controller is lovely for my little enamels. My medium size Paragon, just controlled by the open/closed door is old as my 45 year old son. Still works, after my replacement of one relay. But cost of MC vs std silver put me off it, and enamel is still my first love. Retired in 2017 and never looked back at my day job. Now, very slowly, taking online metals classes, and since i learned to pick solder, am no longer avoiding metal. I also love my Potter jewelry prbess , so many dies to use.