Solder – The Glue That Holds It All Together
Solder (pronounced sod-der – at least in the USA) is used to join metal components together to produce a finished product. How exciting!
In England, solder is pronounced sole-der. From two sources, one first hand and the second one, online, I heard of a theory regarding the origin of the varying pronunciations. The story is that the American pronunciation is too close to the slang word for sodomy: sod! Pronouncing solder as “sod-der” has too many connotations and potentially embarrassing interpretations. To avoid any mixed signals, the “L” is pronounced, ergo: sole-der. Love it!
Back to work! Solder is composed of alloys that produce a material that melts at a lower temperature than the metal you are soldering together. If the solder didn’t melt at a lower temperature than the metal, you would end up melting the metal – you would then be welding or as we jewelers call it, “fusing”.
A lot of jewelry is made using a technique called silver soldering, also known as hard soldering or brazing.
It is an important skill to learn for the metalsmith, as much of your jewelry will require solder joins. Learning to solder will also increase your design scope and offer you more design solutions.
The two goals you should be looking to attain, when soldering, is achieving the strongest bond possible and color matching – matching the solder to the metal. On that note: I’ve yet to find a good copper colored solder. I use silver solder with copper. If I control the amount of solder used (not too much/not too little) and clean up any excess solder well, the seams are difficult to discern. I often use Patinas, which help to disguise any solder lines that I find distracting.
I have used gold solder or gold-filled solder with brass, bronze and gold filled. But, due to today’s RIDICULOUS gold prices, I try to stay away from gold solders – unless I’m working with gold.
- Solder – Solders are alloys of metal. Vague? Well, the composition of the solder depends on the core metal, the manufacturer’s recipe and the type of solder. Most silver solders are composed of a percentage of silver and zinc. Likewise, gold solders are mostly gold with other elements added depending on the color of the gold. The amount of gold, present in the solder, varies by what karat the gold is. See below for more information on gold solder. There are copper solders and brass solders as well as other types. These solders have various issues and are not always perfect matches for your metal.
- Use the highest temperature solder that you can. Usually, you can do 2-3 joins per type. But, often, I can make an entire piece with just hard solder. One of the reasons that this is possible is 1. having control of the heat and 2. the first soldered join loses a bit of its zinc, making the melting temperature, of that first solder application, melt 50°F hotter than originally. Overheating causes many opened seams, for sure. But, successful soldering with one type of solder also depends on how close the seams are to one another.
- Solder pits when the zinc is burned out by over-heating. Keep temperatures as low as possible to avoid pitting, while still providing enough heat to flow the solder.
I’ll explain solder and it’s interaction with the metal it is being used with, in my more detailed section: Soldering 101.
Before we get started here, I want to note something VERY IMPORTANT: When soldering, your solder needs to be as clean as your metal. Also, solder needs to be fluxed – unless it is in a paste form that includes flux (note: Don’t use the GC Electronics soldering paste for silver soldering – its name gives you a clue here!)
Brazing, Soldering, and Welding – What is the Difference?
There is much confusion over the term soldering because, outside of the jewelry realm, soldering is noted as the joining of metals at temperatures 840°F (450°C) and below. This method of joining metal is called soldering and often employs the use of a soldering iron. Solders tend to be lead and/or tin-based and melt at or below 840°F (450°C). But, hey, doesn’t jewelry soldering require really hot gas-based torches, you ask? Yup, it does. Ergo, the problem! We, jewelers, use solders (mainly silver with a dash of zinc) that melt at much higher temperatures like,1450°F/788°C. But, we call it soldering too!
Why do jewelers use the term soldering? What we do is actually called brazing. I’m still searching for the reason why we call it so and have found scant (read: none) information! We do, however, differentiate between the two types of soldering by calling the low melting type of soldering: soft soldering and jeweler’s soldering is called hard or silver soldering.
To understand why we are actually brazing and not soldering, we should look at some of the things that define brazing.
- Metal is joined by employing a “filler” called solder. The filler must melt at a lower temperature than the metals being joined.
- The base metal does not melt in the joining process.
- The materials being joined need to be tight-fitting as the filler flows, via capillary action, into each side being soldered.
- Flux is employed to reduce oxidation because solder will not flow over dirty metal and oxidation is essentially dirt.
- The metals being soldered, and the flux, need to be extremely clean.
- Has the ability to join dissimilar metals.
Jewelry-based, silver/hard soldering follows the same rules. So, it appears, that we are actually silver brazing! Oh well. Let’s just stick with calling it soldering.
- Hard soldering involves very high temperatures (see the chart below). It involves the use of a gas torch which is capable of reaching and surpassing the melt and flow points of the solder. This type of bond is molecular and is much stronger. Silver soldering also allows for neat, clean joins as the solder doesn’t act as a support but has, instead, become joined molecularly to the metal.
This box bezel was made using silver/hard solder. The solder doesn’t need to be draped over the metal to support the structure. Instead, the solder flows into the surrounding metal, allowing any excess solder to be removed – leaving a clean, crisp surface.
Although not a perfect example, I think it will help you visualize the difference between the two types of soldering. Think of soft soldering like using tape and hard soldering as using super glue.
Soldering or soft soldering is defined as a low-temperature process with fillers (solders) melting at 840°F (450°C) or less. The solder doesn’t flow into the metal as much as it flows over and across the metal. The bond is weak compared to brazing and very weak when compared to welding. Fluxes are also used with this form of soldering and the cleanliness of the metal is important. This type of soldering is common in the electronics industry and artforms like stained glass.
This box bezel was made with soft solder (and not well). The solder was laid over the base metal (most likely copper tape used in stained glass windows). This gives, the paper thin copper, strength and a silver color. Note the unsightly globs of solder. As to its strength: you could peel back this bezel with your fingernail.
Welding has an entirely different set of guidelines. The materials need to be the same. The process involves very high heat. The process involves the fusion of the metals being joined. Fillers are generally added to the fused join. Depending on the method of application, the filler can be stronger than the base metal. Essentially, the pieces to be joined are melted together creating a join that is as strong as the metal itself.
We jewelers, also melt like metals together but, we call it fusing not welding. Just to make the terminology more oblique, I guess!
Silver Solder Details
“Solidus is the temperature at which a metal starts to melt; liquidus is the temperature at which it is fully melted.)” from Working with Argentium Silver – Tips and Procedures by Cynthia Eid**.
I’ve included the liquidus points of Argentium, Sterling Silver, and Fine Silver as a comparison with the temperatures needed for solder flow.
- Sterling liquidus point: 1640˚F (893˚C) – 1650° F (899°C)* (varies because it is alloyed)
- Fine silver liquidus point: 1761˚ F (961˚C) (Pure metals have a single liquidus point)
- Argentium 935 liquidus point: 1610°F (877°C)** – 1657°F (903°C)* 1657°F/903°C***
- Argentium 960 liquidus point: 1700°F (927°C)****
|Solder||Flow Points||Use for|
|Extra-hard or IT||1490°F/810°C||Joins if to be enameled|
|Hard||1450°F/788°C||First soldering and additional joins|
|Easy||1325°F/719°C||soldering areas of less stress, repairs;
I borrowed the chart, above, from Riogrande.com and altered it. Note: solder flow points vary depending on the maker. Check with your supplier to find out what temperature your solder flows at.
Please see my webpage on Wire and Sheet Metal. In it, I discuss the properties of various metals, including Argentium, Sterling Silver and Fine silver. Metals are listed first by type (alphabetically) and then alphabetically in their groups. So, Argentium is at the top of the Silver Section.
For a great explanation of liquidus and solidus and the reason why alloys have a range of points for liquidus and solidus, please see this page from the Argentium Guild Blog: Definitions – Solidus and Liquidus by Charles Allenden.
*From AGS Metals
** Cynthia Eid – Working with Argentium Silver – Tips and Procedures
***Rio Grande – Technical Sheet on Argentium 935 Casting Grain
****GS Gold – Argentium and Silver casting grains. Casting Grains and Casting Alloys. Cast temperatures, liquidus temperatures for many metals.
Argentium solder flow points
I don’t know why extra hard has a lower flow point than medium hard – doesn’t make sense to me. Information from Riogrande.com. So, flow points are for their solder.
Argentium wire solder:
- Medium Hard: 1420°F/771°C
- Extra Hard: 1411°F (766°C)
- Easy: 1331°F (722°C)
Argentium paste solder (includes a flux/binder):
- Hard: 1420°F (771°C)
- Medium: 1340°F (727°C)
- Easy: 1295°F (702°C)
- Super Easy: 1185°F (640°C)
Sheet solder has the same gradation and flow points as wire solder.
Forms of solder
Silver solder comes in:
- Paste: generally comes mixed with flux
- Sheet: cut pallions from this sheet. I use French Shop Shears to cut little strips along one edge – like fringe. Then, cut across the fringe, at whatever length you need, for your pallions. You can cut only a few or the whole row at once. Keep storage containers, like these little plastic thingies, to keep different types of solder separate. Label the containers, IT, H, M, E, EE or whatever you’d like.
- Wire: Use as is or flatten it using a rolling mill or a hammer. Then clip the rolled edge to size. For even finer pieces, clip lengthwise and then across. You can make some minuscule pieces this way. Don’t forget to clean solder before AND after running through the rolling mill or hammering it. Never put damp or wet solder into your rolling mill. You will have rust for days…
- Pallions or Chip Solder: I don’t like these as the sizes are pre-determined. If you need a teeny, tiny bit, you have to try and cut a little weeny square of metal in half. If you need big pieces, you need to load a bunch of tiny chunks. Crazy making. Buy sheet and cut your own. Save money too! Yipeedoodles!
Paste and sheet solder can be marked, on their surfaces, as to the type of solder it is but, wire solder is difficult to write on so, a bending system has been devised to mark the wire. Generally, there are only three commonly used bends for hard, medium and easy. I’ve added my own markings for extra easy and IT. See below.
Below are the markings for wire solder:
IT HARD MED EASY
- Differentiate the types of solder by either A) Bends, B) Hammered ends C) Color Coding D) Stamping E) Engraving. This way, you don’t get it confused with silver wire. I put the identifying bends into both my roll of solder and the pieces that I cut off. If you have pallions, keep them in separate, labeled containers. Sheet can be stamped on engraved.
Tips for Solder Storage
Solder, both wire and sheet, can be stored in gallon zip-lock bags, labeled with the type, re-order number, price, and supplier. Better yet, use Pro-Tectant Anti-Tarnish Bags, so your solder doesn’t get tarnished.
Pre-cut solder pallions will tarnish. To protect them from tarnish, use an anti-tarnish bag to store them in. Better yet, buy sheet solder (cheaper) and cut your own. Cut only what you need, at the time.
In Vol.9 No.4, August – September 2013, Wire Jewelry Magazine: Trade Secrets: Teachers share some of their best tips, by Ronna Sarvas Weltman, Artist Kate Richbourg has a great idea for wire and, I think, solder storage. She uses three ring binders with page protectors to hold each different gauge and type of wire. She stiffens the protectors with cardboard. On the spine, she writes the metal type. Great idea Kate!
I found these heavy duty protectors by Avery. You could also, 3-hole punch the Pro-Tectant bags and store them in a binder. Maybe, separate and store them in these pockets by Avery: Avery Big Tab Two-Pocket Insertable Plastic Dividers, 8-Tab Set, 1 Set (11907)
Types of Solder
The reason that different grades of solder are used is because they flow at different temperatures. This is important because there is a danger, when soldering your second, third or fourth element on, of unsoldering your prior joins. What I have found, and I’d be interested to see if others have experienced this, is that after two or three joins, the original join becomes less affected by the heat.
My guess on this is that, in the process of adding my subsequent joins, I’m melting out the zinc (from join one or two) and as a result, my solder is now mostly silver – which melts at a higher temperature. Have you ever tried to unsolder something – especially a piece soldered originally with hard solder? I have spent hours trying to remove pieces and I usually end up having the silver crumble before it will separate from its component parts. Makes me nuts! But, it does add to that big, ever-growing, refining pile! Yippee!
- IT (Intense Temperature) or Extra-Hard Solder is 80% silver and 20% Zinc (at Rio Grande). Sterling silver is 92.5% silver so, you can see how close they are in composition This type of solder is generally used – in jewelry making – for soldering pieces that are to be enameled. Its high flow temperature range is very close to that of silver – which is the main reason that it is not generally used for regular soldering operations. The solder flows at 1490˚ F (810˚ C) while sterling silver flows at 1655˚F (902˚C) – a very close call when soldering. You need to be on your toes so that you don’t melt your sterling. The gap is wider with fine silver as, it’s flow point is 1761˚F (893˚C), allowing a little more wiggle room. Most people use fine silver for enameling and this is one of the reasons why.
- Hard Solder (not to be confused with the term “Hard Soldering” – as opposed to “Soft Soldering” – that done with a soldering iron) is almost always used for the first join and for any areas that are liable to be under a lot of stress. You can solder an entire piece with hard solder – if you are careful with flame/heat placement. Hard solder typically is 75% silver.
- Medium Solder – usually the second or third solder to be used. Don’t get confused, like some students have, that you can only solder 3-4 joins – one for each type of solder. That would severely limit the amount of solder joins that you can do. As mentioned earlier, I use hard for several joins and medium for most of the rest. I can accomplish 10 joins or more with 2 types of solder.
- Medium solder has less silver and more zinc in it that IT or Hard but more than easy. Generally, medium solder is 70% silver. I usually use medium as my third or fourth join. It all depends on how many joins you are making and the stress that those joins will have. Say, I’m making a ring with three solder joins: one being the band, then a doodad on top and plunked on top of that, a small 3mm prong setting. What I’d do is: first, solder the ring join with hard. Second, use the medium for the doodad. Third, I’d use easy for the prong. The prong isn’t going to get tons of stress on it – except during the setting process – and it’s very thin and small compared to the rest of the elements. I don’t want to melt the prongs so, I’d use easy because it melts at a much lower temperature. If I put it on with hard solder, I’d have to be very, very careful with my heat.
- Easy solder – Easy solder is composed of about 65% silver and the rest is generally zinc. I don’t use Easy solder very often as I find that I can usually solder an entire, multi-joined piece with hard and medium. Occasionally, I’ll add a small setting on with Easy.
- Extra-easy solder – this solder is 56% silver (Rio’s formula). It contains considerably less silver than IT, Hard or Medium. Therefore, it contains more zinc. Because there is less silver and more zinc, the solder has a yellowish color to it. Also, extra-easy is not as strong as IT, Hard or Medium. I hardly ever use Extra-Easy solder. Generally, I’d say it’s good for repairs – especially when there is a stone in place and you are worried about the heat ruining it. Other than that, I’d stay away from it.
If you are soldering gold, the gold solder you use contains actual gold.
- Gold solder comes in carat form – ie: 8 K, 10K, 14 K, 18K and 22K.
- Gold solder comes in yellow wire, yellow sheet and yellow paste. There is also white gold solder in wire, sheet and paste (all links to Rio Grande). You can also find rose gold solder but, check the ingredients. You don’t want cadmium in it! Dangerous! Read this article from Rio Grande’s Blog: The Studio.
Well, that’s it for now. If I think of anything else, I will add on to this page. Hope you learned something new. For more information on soldering and setting up a soldering area in your studio, please see my videos on Soldering 101 and the, above mentioned, webpages. Thanks. Nancy
- Stephen Mraz, What’s the Difference Between Soldering, Brazing, and Welding?
- Wikipedia: Brazing. Sourced August 21, 2018.
- How to Set Up a Torch – have a torch, need to set it up? Here’s how.
- Soldering 101, part one and Soldering 101, part two
- All About Solder – You need to understand what you are working with!
- Flat Square Edges on Metal – Important techniques for creating square edges like on ring shanks, tubing, settings, etc. – pretty much any two pieces that you want to solder together!
- Getting Ready to Solder – Important steps before you solder.
- Identify Wire Solder – Mark your solder before confusion reigns!
- Jewelry Studio Safety – Extremely important information that every jeweler should know! Don’t risk your life or your health! Know the dangers of metal dust? If not, don’t sand anything – yet!
- Creating Consistently Sized Spheres – how do you make perfectly round spheres? You might need to know!
- How to Anneal Silver Sheet – an important skill to have otherwise, you can damage your metal and work twice as hard!
- Annealing Wire – Want broken wire? How about melted wire? Need your wire soft and bendable? These tips will help you to avoid these problems and work with ease!
- DIY Fume Extractor for the Studio or Shop – One of the BIG ONES for studio safety. Learn to make your own!
- How to Make a Bezel and Set a Cabochon Part One – Want to solder thin material to thick? Want to set a stone or two? Learn how to create and solder bezels.
- How to Make a Bezel and Set a Cabochon Part Two – Ditto from above.
Soldering Jewelry: How to solder settings, bails and wire. – We solder dissimilar shapes and sizes of metal together, all the time. Want to stop melting your settings or bails? Can you solder wire without melting it?
My YouTube Soldering Playlist – A list of all my soldering videos on YouTube.
Related Web Pages
- About Solder – Learn all about the material you use.
- Acetylene, Torch, Tanks, Safety – A huge page with so much more than info on Acetylene! Learn all about torches, soldering and how to protect yourself!
- Charts – Soldering related charts. Includes things like: annealing temps, compressed gas valve sizes, what temperature does your gas burn at, what are the melting points of your metal. Also, there are wire gauge charts, millimeter to fractions and inches charts, drill bits to wire gauge charts. Lots of information!
- Cleaning Metal – nice to know if you plan on soldering anything!
- On Pickle, Acid, Crock Pots and Baking Soda – How to remove the schmutz left from soldering, how to make your own pickle, how to use pickle and how to neutralize pickle. Tons of info!
- Oxidation, Flux and Fire scale – Why does oxidation occur? Why do you keep getting fire scale, how do you get rid of it. Learn the whys of what is happening when you solder and the solutions.
- The 4 Steps for Successful Soldering – The 4 steps will help you to achieve soldering success!
- Identifying Wire Solder – How to mark your solder so that you always know what type it is.
- Jewelry Tools – Harbor Freight – Cheap tools for the studio!
- Miter Cutting Vise and Jig: Having a hard time squaring up the ends of your ring shanks? Check out this tool!
- Q&A: Firescale/Firestain – See what others have had problems with and find the solutions!
- Q&A: Annealing – How long to hold your annealing temps. Kiln annealing.
- Q&A: Wire Questions. Balling up wire, tapering wire, work hardening wire, straightening wire and more!
- Recipes: They aren’t just for cookin’ anymore!
- Pickle Recipe – make your own pickle
- Prip’s Flux Recipe – make your own flux
- Removing Broken Drill Bits From Your Metal -snapped your drill bit and can’t get it out? Here’s how to remove broken drill bits.
- Removing Copper Flashing i.e.: How to remove the copper coating you might get from pickling. Also, how to remove copper from brass or bronze that comes to the metal’s surface after soldering.
- Soldering in a Nutshell – my list of basic necessities for soldering.
- What Torch to Buy: Trying to figure out what you need to make fire in your studio? Check out this information before you buy!
- Wire and Sheet Metal
- Soldering Questions – One of the most asked after subject matter. Many of my web pages have been inspired by soldering issues and questions.
- Torch/Gas Questions – Portable vs. regular torches, problems with torch, butane torches, water torches, setting up a torch safely, buying torches.