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Professional Zinc Alloy Surface Finishing Solutions

珠宝电镀MC

Jewelry-Grade Gold Plating — 24K, 18K & 14K for Necklaces, Earrings & Bracelets

Your complete guide to jewelry gold plating: color systems, thickness specifications, cyanide-free processes, anti-tarnish sealing, and nickel-free options for hypoallergenic wear.

The QLQ Gold Plating Advantage

From fashion accessories to fine jewelry — gold plating that meets the world's strictest skin-contact regulations

Gold Color Range

24K / 18K / 14K matched

Thickness Control

0.1–5 μm precise

Cyanide-Free

Eco-friendly process

Anti-Tarnish

Sealer blocks oxidation

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The Jewelry Gold Plating Process

Every layer between base metal and the final gold surface is engineered for appearance, wear and safety

1Pre-Cleaning & Wax Removal

Jewelry arrives with casting investment, polishing compound and finger oils. Ultrasonic alkaline degrease (60–70 °C, 3–5 min) followed by DI rinse. Any residue = gold adhesion failure.

Key Parameters
Method: Ultrasonic alkaline
Temp: 60–70 °C
Time: 3–5 min

2Ni- or Ni-Free Strike Layer

Traditional process: nickel strike (5–10 μm) for brightness. Hypoallergenic option: copper strike + palladium flash — no nickel at all. Choose based on your target market.

Key Parameters
Nickel strike: 5–10 μm
Ni-free option: Cu + Pd flash
For: EU REACH, sensitive skin
Industrial electroplating production line with rows of rectangular tanks and blue power supplies overhead.Conceptual illustration based on reference photographs; not test evidence.

3Gold Flash Plating (Decorative: 0.1–0.5 μm)

Thin decorative gold layer. 24K pure gold (pure yellow), 18K (warm gold, 75% Au), 14K (paler, 58% Au). Each alloy has its own electrolyte formulation and color appearance.

Key Parameters
24K: 99.9% Au, bright yellow
18K: 75% Au, warm tone
14K: 58.5% Au, pale gold
Thickness: 0.1–0.5 μm

4Anti-Tarnish Sealing

Gold itself does not tarnish, but the underlying copper or nickel can migrate through thin gold layers. A clear organic sealer (immersion or spray) blocks this migration. For high-wear jewelry, add a thin e-coat top layer.

Key Parameters
Method: Organic sealer dip
E-coat option: 5–10 μm clear
Benefit: Blocks metal migration
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Color & Thickness Guide

Choose by application, wear frequency and budget

Gold TypeAu ContentColor ToneDecorative (μm)Durable (μm)Best For
24K99.9%Bright yellow0.1–0.30.5–1.0High-end jewelry, religious items
18K75%Warm gold0.2–0.51.0–3.0Fashion jewelry, watches
14K58.5%Pale gold0.2–0.51.0–3.0Affordable fashion, kids' jewelry

📌 Jewelry Gold Plating Quick Reference

Decorative thickness0.1–0.5 μm
Durable thickness1.0–3.0 μm
Alloy range14K / 18K / 24K
Ni-free optionCu + Pd + Au
Cyanide-freeYes — sulfite-based
Anti-tarnishOrganic sealer dip
⚠ Nickel allergy is real — know your target marketThe EU Nickel Directive restricts nickel release to < 0.5 μg/cm²/week. For EU-bound jewelry, we recommend 100% nickel-free processing: Cu strike → Pd flash → Au. The palladium layer is the barrier that blocks skin contact with the base metal.

FAQ

What thickness do I need for everyday wear gold jewelry?
For necklaces and earrings worn daily: 1.0–3.0 μm gold. Below 0.5 μm, the gold layer wears through in 3–6 months on high-friction areas like necklace clasps and earring posts.
Is cyanide-free gold plating as good as cyanide-based?
Yes — modern sulfite-based gold baths achieve > 99.9% purity and excellent brightness. The only limitation is deposition rate: cyanide baths plate faster. For jewelry thicknesses (0.1–3.0 μm), sulfite is perfectly adequate.
Why does my gold jewelry turn skin green?
Base metal copper oxidizing through a thin gold layer. Solution: increase gold thickness to ≥ 1.0 μm and apply an anti-tarnish sealer. Our nickel-free process with a palladium barrier layer eliminates this entirely.
Can you match a specific Pantone gold shade?
Yes — we have 8 standard gold tones from yellow (24K) to greenish (14K white gold). We can formulate custom alloy ratios to match your swatch or Pantone code. Lead time: 7–10 days for formulation.
What is the difference between hard gold and soft gold for jewelry?
Hard gold (alloyed with Co or Ni, 150–250 HV) is more scratch-resistant — better for rings and clasps. Soft gold (pure, 50–90 HV) is warmer in color and preferred for earrings and delicate pendants.

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