Plating Chemicals for Nickel Free Jewelry
Most often, the base metal for gold plating is copper or copper alloy. When gold is plated on copper, a barrier layer must be plated between copper and gold to prevent copper diffusion in gold and eventual migration on gold surface. A sulfamate nickel plating is used most often, but for jewelry it should not be used due to the potential allergy hazard of nickel.
There are two main methods for producing nickel-free deposits on fashion jewelry.
substitute the nickel with palladium over bright acid copper
Bronze (copper, zinc, tin) over bright acid copper for bright finishes.
Opt for Gold Micron, Palladium, Ruthenium plating[AB1]
The gold (copper) micron gold plating electrolyte has good tarnish resistance and is used as a top thick coat in fashion accessories and jewelry as decorative top coat.
Palladium electrolyte is used as a barrier coating as well as a top coat or an undercoat due to low porosity deposit and bright white finish.
Black Ruthenium can be plated directly over gold, platinum, palladium, silver and gold plate. When plating over non-precious metals, gold pre-plating is required.
Why opt for rhodium plating?
Rhodium plating is often added onto white gold or silver jewelry to increase shine, luster and durability. Rhodium plating will also make the metal more scratch resistant and, when used on silver jewelry, less prone to tarnishing.
Upsides to rhodium plating is it’s nickel free, making it hypoallergenic. Most white jewelry consists of yellow gold mixed with a small amount of nickel to give it the “white gold” color. Nickel allergy is increasing across the population, so it makes sense to choose your metals wisely.
Are there any downsides?
While rhodium plating can vastly increase the shine and durability of your jewelry, however it will wear off over time. Typically, rhodium plating needs to be reapplied every couple years, though it depends. The body chemistry is such that the plating wears more quickly than that.
Opt for Bronze/ Copper Plating : [AB2]
White Bronze & Yellow Bronze Plating: Best suitable for people allergic to nickel. Used as an under coat before gold plating.
Copper plating processes may vary in composition to satisfy customers’ requirements for specific decorative applications. Copper’s high throwing power provides excellent adhesion to base metals as well as a flawless, mirror-like deposit.
Thanks to its exceptional corrosion resistance, copper is a popular choice as a functional finish and growing aesthetic in furniture and fashion accessories, such as hand bags and footwear. Acid copper plating is often utilised as a replacement for nickel-based processes in all decorative applications where nickel-free materials are required. It provides a layer of excellent levelling power underneath the barrier layer (white bronze or palladium plating) and the final layer (gold, silver, rhodium or ruthenium plating).
[AB1]Geeclad NF 1-2N, Geeclad NF 2-3N, Geeclad NF 3N, Geeclad NF 5N, Geeclad EL-407, Geeloy 18Kt Yellow
Palladure 100, Palladium Flash, Palladure BP
P&S Black Ruthenium, P&S Grey Ruthenium
[AB2]P&S White Bronze, P&S Yellow Bronze, P&S Yellow Bronze LF,