Laser Gold Welding Machine

In traditional jewelry manufacturing, welding typically relies on torch soldering. Although this method has a long history, it comes with clear limitations: it requires solder (which reduces metal purity and may cause color inconsistencies), it has a large heat-affected zone (wide heating can damage nearby gemstones or soften the metal through annealing), and it is difficult to work on extremely delicate components.

As consumers increasingly demand higher craftsmanship and as complex hollow designs become more popular, the jewelry industry’s need for precision and efficiency has reached its peak.

The introduction of laser welding technology has completely transformed the situation. It has become an essential tool in modern jewelry workshops for several reasons:

• Seamless welding:
  No solder is required. The laser directly fuses the base metal, preserving the purity of precious metals (such as 18K gold or pure gold), and the weld does not oxidize or discolor.
• Minimal heat impact:
  Because the laser beam is highly concentrated, heat does not spread. This allows jewelers to perform repairs even on pieces set with diamonds, pearls, and heat-sensitive gemstones (such as emeralds or opals) without removing them.
• Extreme precision:
  With microscope-assisted operation and a laser spot as small as 0.1–2.0 mm, it can repair micro-defects that are barely visible to the naked eye.

Beause Melting metal to mend or re-work your jewellery pieces will help you to expand on the style of jewellery you offer and the variation of jewellery pieces you supply. At Cooksongold, we supply all the metal melting equipment you need to successfully liquefy metal.

From hand torches to scorifiers, tongs and butane gas lighter fuel – we really are the one-stop shop for all your metal melting equipment. Browse our range of metal melting equipment and find our quality melting tools in a selection of shapes and sizes.

3.1, Jewelry manufacturing factories

Casting Porosity Repair

Process Background & Pain Points: Modern jewelry mass production primarily uses the lost-wax casting process. When molten metal is poured into plaster molds and solidifies during cooling, tiny surface pits often appear due to metal shrinkage or trapped gas bubbles in the mold. These pits, visible to the naked eye, are known in the industry as “porosity” or “air holes.”

Why Repair Is Necessary: If left untreated and polished directly, porosity appears as black spots, rendering the piece defective. Remelting the casting wastes significant labor, electricity, and metal. Traditional soldering often causes slight color differences with K-gold, and over time, the repair area may oxidize and darken, making the piece unsuitable for high-quality jewelry.

Laser Solution: A laser beam can directly “push” the surrounding metal to fill the holes or melt same-metal wire into the porosity. The repaired area fuses seamlessly with the base metal, leaving a dense, flawless, color-consistent repair without gold loss. This saves what would have been scrapped castings and greatly reduces production costs.

Batch Assembly & Joining

Pain Point: Complex jewelry composed of multiple components (like tennis bracelets with moving joints or two-tone rings) traditionally requires flux, torch welding, and acid cleaning to remove oxidation—labor-intensive, time-consuming, and environmentally polluting.

Laser Solution: Laser welding requires no flux or acid cleaning. Factories can use fixtures to perform fast spot welds—one weld per second—dramatically shortening assembly line time.

Integration into Automated Production Lines

For high-volume production of basic components (such as gold ear posts or necklace clasps), factories integrate fiber lasers into automated welding stations or robotic arms, enabling 24-hour unmanned precision welding while ensuring every weld maintains consistent strength.

3.2, Gold shops / jewelry stores (repair services)

Repair with Stones Set & Risk Control

Pain Point: This is the biggest nightmare for traditional jewelry repair. When a customer brings in a ring set with emeralds, pearls, coral, or opals—stones extremely sensitive to heat that can crack or discolor under high temperatures—for tightening loose prongs, conventional methods require removing the stones first, welding the prongs, and then resetting them. This process is time-consuming and carries a high risk of chipping or damaging the stones, often leading to costly compensation.

Laser Solution: The laser’s heat-affected zone is minimal (acting only on the spot), and heat does not transfer to the stones. Jewelers can weld under a microscope as close as 0.5mm from the stones. No stone removal is needed, and the repair is ready immediately. This eliminates the risk of stone damage and allows jewelers to accept high-difficulty repairs that traditional shops would avoid.

Seamless Resizing

Pain Point: Customers often need ring resizing after purchase. Traditional torch welding leaves a visible “black line” or shadow at the joint (due to low-melting solder and impurities), and the metal at the joint tends to be brittle.

Laser Solution: Laser welding fuses the parent metal itself, making the joint’s physical properties and color fully consistent with the rest of the ring. After polishing, there are no visible weld marks, achieving truly seamless resizing and enhancing customer satisfaction.

Chain Breaks & Hollow Jewelry Repair

Modern 5G gold or 3D hard gold jewelry often has hollow structures with extremely thin walls. Traditional torch welding melts and deforms these pieces easily. Only laser welding can precisely control energy to repair these ultra-thin hollow components without damaging their overall shape.

3.3, Independent designers / handmade jewelry studios

Ultra-Fine Structures & Filigree Work

Pain Point: Designers often create extremely fine gold wires (0.2mm–0.5mm) for openwork, lace, or filigree patterns. The flame from a traditional torch is too large and difficult to control, causing the delicate wires to melt or ball up instantly.

Laser Solution: Lasers can precisely control pulse energy and spot size, melting only the contact points between two fine wires without damaging the rest of the structure, making extremely intricate openwork designs possible.

Mixed Metals Joining

Pain Point: For aesthetic purposes, designers may want to combine 18K gold with 925 silver, or titanium with gold. Due to the significant differences in melting points and thermal expansion coefficients, traditional welding cannot achieve a strong bond.

Laser Solution: The high energy density of lasers enables metallurgical bonding between different metals, allowing the creation of unique two-tone or multi-material jewelry.

Antique Jewelry Restoration

Many antique pieces feature fragile enamel or precious historical patina. Laser welding is non-contact and extremely precise, repairing only the broken areas without damaging surrounding delicate enamel or the original aged finish.

3.4, Precious metal processing companies

Dental Prosthetics Fabrication: Repairs and bridge connections for dental alloys (such as gold-platinum alloys or cobalt-chromium alloys) require extremely high biocompatibility. The oral cavity cannot contain harmful heavy metal solder components. Laser welding uses the base material itself without adding solder, perfectly meeting medical and hygiene standards.

High-End Watch Repair: Used for fixing broken gold watch bands or dents on watch cases (by building up gold wire to fill depressions), restoring the watch’s original value.

When purchasing, the most commonly discussed parameters are the power rating (60W, 100W, 200W…) and the type of laser source.

4.1, Differences between 150W, 200W, and 300W

Here, the power usually refers to the average power. For most gold (18K, 24K) and platinum jewelry:

60W – 100W: Entry-level / light use. Sufficient for most gold chain welding, fine ring resizing, and porosity repair. For a pure gold store, this power is adequate.

150W – 200W: Gold standard / all-rounder (most recommended).

Why recommend 200W? Although welding gold alone doesn’t require such high power, if you need to weld silver, high power is necessary. Silver has extremely high reflectivity (much harder to weld than gold) and conducts heat very quickly. Low-power machines attempting to weld silver are like “pouring water on a mirror”—it simply won’t melt. A 200W machine provides enough peak power to overcome silver’s reflectivity.

300W+: Industrial / heavy-duty processing. Used for very thick pieces, continuous high-intensity factory work, or large-scale thick silver jewelry production.

4.2, Pulse laser vs. continuous laser

Pulsed Nd:YAG (Lamp-Pumped):

This is currently the standard configuration in the jewelry industry (box-type machine with a microscope).

• Advantages: Very high single-pulse energy, ideal for precise spot welding, prong repairs, with the most accurate heat control.

• Disadvantages: Requires periodic replacement of the flash lamp (consumable).

Continuous Wave Fiber Laser (CW Fiber):

Commonly used in handheld welders or factory automation lines.

• Advantages: Maintenance-free, long lifespan, suitable for long seam welding (e.g., fixing bracelet joints).

• Limitations: For extremely fine repairs (such as 0.3mm prongs), the heat accumulation of continuous lasers is harder to control, which can lead to overheating.

Within your budget, focus on the following key indicators:

Microscope Quality:
You’ll be looking through it all day. A Leica or equivalent-grade microscope is preferred, as it effectively protects your eyesight and provides clear depth of field and accurate color reproduction. Low-quality microscopes can cause dizziness, fatigue, and poor focus.

Cooling System (Water Chiller):
Choose a machine with a built-in powerful water cooling system (with compressor cooling). Lasers are extremely sensitive to temperature—poor heat dissipation can lead to energy decay during prolonged work (the first pulse is strong, the tenth pulse weak, causing inconsistent welds).

Beam Quality & Beam Expander System:
A high-quality machine can maintain uniform energy distribution when adjusting the spot size (flat-top or near-Gaussian distribution), avoiding “center burns through while edges remain unmelted.”

Working Chamber Space:
If you often repair bracelets, large necklaces, or decorative items, you need an open or spacious chamber (with a well-placed joystick). Otherwise, reaching inside becomes awkward and inefficient.

Although it’s called a “Gold Welding Machine,” it’s actually an all-rounder for precious metals.

Gold:

• 18K/14K: Easiest to weld, flows well, perfect results.

• 24K Pure Gold: Very soft and highly reflective. Lower voltage and longer pulse width are needed to prevent piercing or collapse.

• Rose Gold: High copper content, prone to oxidation and darkening when cooling. Argon shielding gas is required to keep welds bright.

Silver:
The most difficult precious metal to weld. Requires “high voltage, short pulse width, defocusing” techniques and high-power machines (200W+ recommended).

Platinum & Palladium:
Excellent welding performance, melts without flowing and sets quickly. Laser is the best tool for platinum, fully solving the traditional difficulty of welding platinum.

Titanium & Stainless Steel:
Fully compatible, commonly used for jewelry clasps, medical-grade earrings, and fashion jewelry.

Mixed Metals:
Laser can weld gold to silver, gold to steel, enabling special bi-metal or multi-material designs.

Summary Recommendation:
For a standard jewelry repair shop or custom studio, a 200W desktop pulsed Nd:YAG laser spot welder (equipped with a high-quality microscope and optional external CCD camera for client demonstration) offers the best ROI. It can handle factory-level batch casting porosity repair, fine in-store resizing, stone-in repairs, and even silver welding.