Back to basics: Don’t kick the bucket

by charlene_voisin | December 1, 2012 9:00 am

By Tom Weishaar

Editor’s Note: This is the final instalment in a six-part series that aims to break bad habits and do away with shortcuts bench jewellers often pick up. This time, the author turns his attention to repairing chains.

I’d like to begin this article with a short discussion about pricing chain repairs. These jobs are a great source of dependable income for bench jewellers, as they take very little time and the cost is low. An experienced jeweller should be able to fix approximately eight chains an hour. When I began repairing jewellery, the shop I worked for typically repaired 30 to 50 chains each day. Way back then, we charged a flat rate of $2.50 for each chain solder. That was considered good money 35 years ago for such a simple task, but it pales in comparison to today’s average retail price of $15.

I categorize chains as either open-link, flat-link, or woven, each one more difficult to repair than the last. These categories can be further subdivided according to difficulty. Take, for example, a wide herringbone and a small cobra chain. Both are flat-link, but the herringbone, given its width, is much more difficult to repair. Rope chain is another example, requiring two solders (i.e. top and bottom), while a snake chain needs only one. Both fall into my woven category, but should they be priced the same to repair, or should jewellers charge more for the multiple-solder rope? Most jewellers I’ve spoken with find it easier to simply charge a flat rate for chain repairs. The price is generally too high for simple chains and too low for complicated ones. In the end, it all evens out for the jeweller, although it is not necessarily fair for the customer.

For years, I was an advocate for using a complicated step pricing system for chain repairs. It nearly drove me crazy trying to educate our sales staff on the subtle nuances of these types of jobs. In the end, I found I had neither the time nor the energy to use it. I hate to admit defeat, but I am now happy when the staff just remembers to charge for the repair.

Another oddity about chain repairs is how critical people can be when a repair is first inspected. This particular job is always held to the highest standard, perhaps because chains are worn on the neck, high up and near the face. I don’t have a good explanation why a customer will turn a blind eye to a more expensive and poorly done repair on other jewellery, but will hold one’s feet to the fire when it comes to a modestly priced chain repair. Whatever the reason, I know I need to pay close attention when I repair a chain.

Technology versus the torch

The basic procedure for repairing chains changed little during the whole 20th century. However, by 2000, the widespread use of the laser welder turned bench jewellers’ lives upside down. For the first time ever, the laser gave us the ability to add metal with pinpoint accuracy. That may not sound like a big deal, but for a bench jeweller, the laser gave us our first-ever safety net. For instance, we could make mistakes in our metal work and fix them without having to remove delicate gemstones.

Right up front, I want to say I love my laser welder. Our store was among the first to purchase one, and although ours is now getting to be an older machine, I still use it every day. If our laser welder ever kicks the bucket, I’m sure we’ll have a new one on order within 10 minutes. I have to admit when we first bought the laser, I nearly abandoned my torch, believing it was a tool I could use for every type of repair. It took some time before I understood there were a few tasks for which my old torch was better suited than the laser.

Those of you who own a laser welder already know they are very user-friendly. I have even shown salespeople how to use one for simple tasks. This is in stark contrast to the years it takes to develop good torch skills. Perhaps it’s the difficulty of torch soldering that causes bench jewellers to be so willing to stop using this method in favour of the laser. In this article, I will discuss repairing chains using a torch and laser, and those applications where one method will produce better results over the other.

Soldering link chains

All chains break, and learning to repair them is the traditional starting point for most bench jewellers’ careers. I know I cut my teeth on chains, right after I ruined a very nice coral ring, that is, but we don’t need to tell that story.

Snipping out the bad section of a broken chain is always the first step. For this task, we need a sharp pair of cutters with a flush back. Unfortunately, this type of cutter gets used for many different unintended tasks over the course of the day, and by the time they’re needed for a chain repair, they won’t cut soft butter. It’s a good idea to keep cutters sharp or purchase an extra pair and label them ‘for chains only.’ Please see Tom’s Tool Tip here[8] for information on sharpening cutters.

Chain links are often very tiny. As such, learning to solder them is a matter of heat control. Several decades ago, a brilliant jeweller invented a system of using hypodermic needles as torch tips. Soldering fine link chain, however, is not just a matter of putting the smallest tip on your torch and pointing a tiny, though hot flame at a broken link. It’s much more subtle than that. When soldering fine chains, I use the side edge of the flame near the torch’s opening, where it is least hot. I call this approach ‘peripheral soldering’ and it works great. Easy-flow solder is my first choice for chain repairs, as opposed to hard or even medium solders.

Laser welding link chains

Just like torch soldering, laser welding has a few nuisances of its own. Successful laser welding depends on the thickness or mass of the metal being welded—approximately 0.5 mm in diameter, or the thickness of a small jump ring, is a good size. This may seem very small, but anything much thicker prevents the laser pulse from penetrating the metal’s core to create a complete weld. Heavier items like a ring shank may need to have a V-notch cut into them down to the core and then filled with both a primary and secondary pass of the laser using a filler rod. Laser welding on items thinner than 0.4 mm is also problematic, as they have a tendency to explode under the pressure of even a mild laser burst. It’s these small subtleties that ought to be considered when deciding to use either a laser or a torch on a particular chain.

In the side-by-side comparison seen here, notice how the laser-welded chain on the left is superior to the torch-soldered repair on the right. Not only did the laser do a better job, but it did it twice as fast as the traditional torch. An example like this shows how making repairs, such as adding a new jump ring to a chain or welding a spring ring closed, are fantastic jobs for laser welders and big timesavers. When a laser can be used successfully on a chain, the repair time is generally cut in half.

Repairing flat chains

For our second example, let’s look at the flat-link serpentine chain in the photo to the left. These types of chains fall in the second category—cobra-link, herringbone, C-link, and box chain are others. All were very popular a few decades ago, but have since taken a back seat to today’s woven and double-link styles. Flat-link chains were nice when worn alone—they looked big, but because the metal was so thin, they didn’t cost much. The problem with these chains, however, is they kink and break easily, especially when worn with a pendant.

Flat-link chains are made of very thin gold stock that melts easily. Therefore, we can use neither higher-temperature hard solders nor can we apply heat directly on the metal. I’ve learned applying a torch’s peripheral heat is the best method of repair. To begin, I heat a section of a soldering pad. Next, I use a pair of tweezers to move the chain with some solder on it into the heat.

After the soldered end cools, I snip through the solder using a pair of flush-end cutters. This eliminates the bulk of the material, leaving just enough to complete the repair. I also prefer to snip directly through the centre of the link. That way, when I match it up to the other end of the chain, the two halves come together and are virtually invisible.

Soldering the two halves of chain back together is also done by applying peripheral heating. I use a flat soldering pad and point the torch’s heat just past the chain links. As the pad becomes hot, the heat’s footprint increases in size. In just a moment, the soldering pad is up to temperature and the soldered ends of the chain flow together. This is the safest method I have found for soldering delicate chains.

Laser welding flat chains

Many of the chains bench jewellers repair every day are stamped out of metal sheets thinner than 0.15 mm. While laser welding the end of a thin chain to a jump ring may be a simple task, creating an invisible laser weld within the body of a broken flat chain can be difficult.

The serpentine chain in the photo to the left proved very difficult to laser weld, even with the laser’s voltage dialed down to approximately 200 volts and the beam’s diameter opened to 20. To complete the task, I used the laser to melt the broken ends. Doing so transformed the thin, layered link into a more solid mass. This is a similar concept to adding solder to the chain ends prior to making the repair. Creating a solid mass allows more heat to be used during the repair. After fusing the tips of the chain, I snipped through the now solid mass to get a flat cut end. Next, I welded the two ends together.

It is clear in the photo to the right that the repair of the laser-welded chain on the left does not look as clean as the thinner soldered chain next to it. While there is a slight visual difference between the two, both repairs only affected a single link, meaning the chains are still very flexible. I’d say that although the soldered chain looks best, both repairs would be considered acceptable.

Repairing woven chains

Depending on the type, woven chains can be very difficult to repair. Take, for example, hollow-link rope chains. These are typically stamped out of metal less than 0.10-mm thick. They are so thin, they have to be manufactured in temperature-controlled kilns. A torch will almost instantly melt one, while the links are sure to explode when a laser is applied. These chains are nearly impossible to repair unless you simply flood them with solder to build up mass. To me, it seems unfair for bench jewellers to be held responsible to do high-quality repairs on hollow chains.

Consider the kinked 1.2-mm diameter white gold snake chain in the top photo. The kinking occurred due to a rather heavy pendant being hung from it. The individual links in this chain are made of woven wires approximately 0.1-mm thick. To repair this chain, I used the same techniques for both torch and laser described in the section on repairing flat-link chains.

When I tried laser welding this chain, the wires exploded. Additionally, fusing the ends into a solid mass proved more difficult than the previous flat-link chain. I eventually used a white gold filler rod and overbuilt the ends of the chain before I could laser weld them together. The finished result came out bulky, requiring sanding and polishing. To torch-solder this same chain, I once again used peripheral heating.

As you can see in the bottom photo, the difference between the laser-welded chain on the left and the torch-soldered chain on the right is quite dramatic. Here, the repair is nearly invisible. With only a small stiff area, the result is one with which a client would be happy.

For slightly heavier link chains and adding clasps, lasers are the preferred repair method, while torch solders are more appropriate when working on chains made of thinner metals. The perfect solution is for jewellers to be proficient at using both pieces of equipment and to keep in mind which tool will achieve the desired result.

I’ve now concluded a year’s worth of ‘back to the basics’ articles. Through these columns, it has been my goal to illustrate how to properly complete the most common repair jobs using the right tools and techniques. I know through my own experience that when bench jewellers deliver outstanding quality to their customers, their reputation and success grow. Thank you to everyone for your feedback and questions.

Starting with the February issue, I will present a new series of articles that combine the skills and techniques shown during this past year in the creation of six custom-made pieces. These columns will illustrate and discuss more complex bench techniques ranging from advanced stone-setting to hand-engraving and fabrication. I hope you’ll join me as I go over the top on custom work.

[15]Tom Weishaar is a certified master bench jeweller (CMBJ) and has presented seminars on jewellery repair topics for Jewelers of America (JA). He can be contacted via e-mail at tweishaar@cox.net[16].

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