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

▼

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

Before

After

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

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

▼

Color & Thickness Guide

Choose by application, wear frequency and budget

Gold Type	Au Content	Color Tone	Decorative (μm)	Durable (μm)	Best For
24K	99.9%	Bright yellow	0.1–0.3	0.5–1.0	High-end jewelry, religious items
18K	75%	Warm gold	0.2–0.5	1.0–3.0	Fashion jewelry, watches
14K	58.5%	Pale gold	0.2–0.5	1.0–3.0	Affordable 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.

Get a Free Quote Today

Send us your samples or drawings — our engineers reply within 24 hours with pricing and technical advice.

Workshop Planning Data

Jewelry Plating MC — Data Zinc Alloy Finishing Managers Need

Gold plating (rack and selective) and gold electroforming produce premium jewelry-grade finishes on zinc alloy, brass and silver — with tight karat control and high-value output per square meter.

350 m²Workshop Area

14 peopleTeam Size

120 kWInstalled Power

100-300k pcs/dayDaily Output (10 h)

Quality Inspection & Control

Check item	Method	Acceptance standard
Gold thickness	X-ray fluorescence	0.05-5.0 μm per karat spec
Karat / purity	XRF analysis	24K ≥ 99.9%, 18K ≥ 75% Au
Color match	Colorimeter ΔE	ΔE ≤ 1.0 vs karat master
Adhesion	Bend + thermal shock	No flake at 150 °C × 30 min
Wear resistance	Taber / rub test	No wear-through at spec cycles
Contact resistance	Milliohm meter	≤ 10 mΩ for industrial contacts

Workshop Layout & Floor Area

Zone	Area
Clean-room plating line	110 m²
Electroforming shop	80 m²
Precious metal store (vault)	20 m²
QA lab + XRF	40 m²
Rinse / DI / recovery	50 m²
Waste & gold recovery	25 m²
Utility & lockers	25 m²
Total workshop	350 m²

Manpower & Shift Plan

Role	Headcount
Platers / operators	7
Gold solution technicians	2
QC inspectors (XRF)	2
Precious metal control	1
Supervisor	1
Maintenance	1
Total (2 shifts × 10 h)	14

Power & Utility Demand

Equipment	Demand
Rectifiers (precious metal)	35 kW
Heaters / chillers	30 kW
Pumps / filters	15 kW
Clean-room HVAC	18 kW
Electroforming power	10 kW
Lighting & auxiliary	12 kW
Installed total	120 kW
Typical running load	≈ 95 kW

Production Flow Chart

PretreatmentPolish, clean, activate

Strike LayerNickel or silver strike

Gold PlateRack / barrel / selective gold

Rinse & RecoveryDI rinse + gold drag-out recovery

Dry & QCXRF thickness + color check

Protect & PackSeal, wrap, pack

Daily Capacity — 10-Hour Operating Day

Parameter	Value
Cycle time	30-60 min
Load per batch	30-80 kg
Batches per 10 h day	10-16
Daily output	100,000-300,000 pcs
Monthly output (26 days)	2.6-7.8 million pcs

Output Value Estimate

Parameter	Value
Plating fee per piece	USD 0.02-0.12
Daily output value (10 h)	USD 8,000-25,000
Monthly output value	USD 210,000-650,000
Annual output value	USD 2,500,000-7,800,000

珠宝电镀MC

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