Many of you have heard me talk about lasering jewelry, or laser soldering, over the years. Time to devote some blog space to what this actually means, and what is possible or not possible with laser soldering.
What is laser soldering? Laser soldering is a high tech, low heat, alternative to regular soldering. Laser soldering uses solder, but instead of heating it with conventional methods, it is heated with a laser beam and then literally “shot” onto the area that is to be soldered together with high precision. The heat used is below 450 degrees Celsius (below half of regular soldering temperatures). Laser soldering is achieved with a laser solder machine which currently costs in excess of $5000. Its original use is in computer technology (to solder together components of circuit boards) but it is now widely used in the jewelry industry as well.
What are the advantages of laser soldering? The advantages are precision (adjacent components like gemstones are not affected by the technique) and the heating source is not near the item to be soldered so that any components that are sensitive to heat will not be affected. So for instance, if an earring post falls off of a stud earring, it can be lasered back without the gem having to be removed. There’s also no risk of melting the components themselves, which is a great advantage if the components are very tiny, like a small jump ring for example. Laser is also just about the only technique that works for channel wire because your soldering joint is directly next to the gem.
Examples of application: very tiny joints, such as adding a jump ring to a pendant or earring. Ring sizing of rings with gemstones, or ring and pendant repair where the gem should not be removed. Repairs of earring posts, conversion of stick pins to pendants. Laser soldering can also be used to fill porosities in a casting. Porosities are tiny air bubbles or pockets that can occur during the casting process and that can “open up” during pre polish if they are just under the surface (mostly that is where they are).
Here you can see the imperfection at the top of the jump ring prior to being soldered:
What are the disadvantages? The soldering joints are small and use very little solder. That means they are less secure than conventional solder. This is not a big deal when you size a ring because you can just “shoot” many little bits of solder onto the joint – see video. But earring posts, which have to take a little bit of pressure when you put them on, but are otherwise pretty tiny, are best soldered with conventional techniques. With earring posts, lasering is a plan B only. Another disadvantage, or rather, a risk is that if you have a tiny soldering joint right next to a gem, is that you can “miss the target” (see below for photo example)and hit the gem instead. Then you “fry” a little hole into it. Channel wire joints are notorious for that happening, that’s why it is so expensive. It takes great precision and patience. There also seem to be some gems, or gem colors, that attract and divert the laser beam. We’ve had that problem a lot with red garnets, which is why I stopped wrapping them in channel wire.
What does laser solder cost? As mentioned above, the cheapest machines available for laser soldering, or laser welder, start at about $5,000. Really good machines can cost up to $50,000. Correspondingly, when you get some work done with a laser soldering machine, the costs are higher because the costs of the machine have to be absorbed in addition to the time spent soldering. A simple laser joint (attaching a jump ring) retails at $10-12 in my shop. Ring sizing actually costs ME more than what I charge you. A small change in size costs me $25-30, a larger ring can be $50-60. When I sell rings I partially absorb that cost through the price of the ring itself. So when you go to a jewelry store and they tell you its $100 for ring sizing, that’s not an unfair price. Doing a good job also takes at least a half hour (cutting metal, adding metal, shaving to make it match, repolish, plus gold costs if needed). Downsizing is easier but can still change the curvature of the ring and open up settings, which then have to be rechecked in turn.