A Heated Discussion: Soldering vs. Fusing

Let’s try to keep this discussion to the topic of sizing rings in particular, even more specifically, gold and silver alloys (my apologies, Mr. Grahl, but we know platinum is special).

For the last 15 years of my bench career, I have sized rings with solder. Usually a plumb solder to match the alloy being sized. However, people on this forum have occasionally mentioned fusing (using the same alloy) to make the joint. This usually leads to hours of nervous fretting while I question all I’ve been taught. In these moments of self-doubt, I have attempted to fuse and have had limited success. Then I revert back to my soldering ways until the next time someone triggers me. So I want to know what are the accepted guidelines for when to solder and when to fuse. Do some alloys work better for this than others? Is this simply personal preference or has experience led you to chose one method over the other?

Let the games begin!

Over the years I’ve worked with or known at least 50 full time goldsmiths and I can only think of one who fused sizings regularly. The main objective with sizing or really any repair is to do it undetectably. So deliberately melting a few millimeters if shank seems counterintuitive to me. If you solder you don’t deform the seam at all, just add a little new material. If you fuse you cause the seam area to melt, unnecessarily creating a situation that requires more clean up. Getting in the habit of melting finished components in order to join them makes no sense to me.

That said, on rare occasions I do fuse but never with gold or silver sizings. Mark

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You and I are on the same page. This has been my thinking and experience. I guess the question I would like to have answered is why those that fuse do so.

If you can fuse/ weld a seam, say a ring shank, then you are basically creating a seamless shank. There is no different alloy introduced, so melting points and color all match….

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It all depends on the circumstances and the metals involved. When working in a busy repair trade shop especially on rings that have been soldered before we just soldered away. Mind you we were each sizing dozens of rings a day at 5 bucks a pop. Many of questionable parentage and karatage.
When working in a manufacturing situation if it was a new ring that we had made and 18kt or higher we always fused. If it was 14kt we would use a combo of 50% hard solder mixed with 50% gold or plumb solder.
In platinum that has not been sized we always fuse. Mind you this is all with a torch not a laser.
I also fuse fine silver or continuum silver. Standard sterling alloys can’t take it. I learned how to do this from men who learned before WWII many of them European trained where karat testing standards are higher. Used to be that a piece of English or European jewelry had to test at karat including the solder seams. Plus when making tubing we like ours seamless. Whether you use it or not in everyday practice I think it’s important to learn how to fuse so that you can learn the limits of metals. You have to push it to it’s limits to really know it.
Have fun and make lots of jewelry.
Jo Haemer
www.timothywgreen.com

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I am a bit late to this conversation, but I’ve been fusing my fabricated bands for nearly 20 years primarily because I alloy many of my metals and I don’t have to be concerned about a color match with solder.
James Dailing

Hi folks,
I have a tendency to fuse whenever possible, no matter what the material. It saves the possibility of a visible seam, as well as the dreaded finding of a seam if future sizing is anticipated. Though it’s how I do most joints, it’s just not an automatic go-to (for me) though.
The variables of types of stones , location relative to the solder joint and the possibility of mixed metals (yellow and white combinations for instance) all have to be taken into account.
Like Jo, any fusing I do is with a torch, The piece is heat sinked if necessary. Some metals are particularly easy, 18k rose, platinum, nearly any yellow gold will fuse well, silver requires a very practiced touch, but all can usually be done as easily as solder.
I’ve been out of the trade / repair world for many years, however I still see quite a few sizings from previous client work. I will always prefer to start with a piece that has not been soldered at the back of the shank, hence my perspective on fusing.
The primary issue is having a matching color to work with. When sizing down, I save the cut out section and roll it to about 1 or 2 tenths of a millimeter, making sure there is just enough tension to hold the piece I’ve rolled under very slight pressure between the shanks. The piece will overlap the shanks by a millimeter or so all around. Then it’s a matter of bringing up the heat . You’ll see the thin sheet melt first telling you that you’re near the fusing point
Then, go in a bit closer with the torch and the metals will join.
This is a very simplistic description I realize, but here practice is everything.
The advantage is a seamless and very strong joint.

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I thought this thread might get a little confusing.

But people sharing snippets of their knowledge should help the conversation flow.

I’m going to start giving this a try. If it fails, I’m blaming all of you.

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I’d love to try this! I must have an old ring around that I can fuse to shrink!

So far, so good. I sized a 14k yellow gold ring down from a 7 to a 3-1/2 and thought since the chances of failure were already stacked against me I would give it a try. It worked like a charm and I can’t wait to get to my next sizing job to try it again.

Congrats. But not all alloys torch weld as well as others. I also try to size a little small and forge the bulbous weld a little.

Please excuse any typos-- curse my clumsy digits…

That’s what I did this time, taking 3-1/2 sizes out, I had plenty of metal to work. I’ve got a 10K yellow gold ring up for today’s challenge.

10k is an interesting alloy in that there is more alloy than gold……

The 10K went perfectly, even with the top suspended in water as it had an emerald-in-name-only. White gold seems to be the problem child. It was 14K white gold from a country located west of Japan and south of Russia. These alloys can be a problem with soldering so I wasn’t too surprised. Any tips for white gold alloys?

What is the typical process for sizing up? Sizing down I’m taking my flattened piece of stock and pinching it in the joint, but that seems impractical when going up. Especially as I’m accustomed to notching my stock when going up in size.