Electroplating is the process of electro-depositing a precious metal such as gold,silver,rhodium,copper or bright nickel onto a different surface thereby enhancing its finish.

The process carried out in a tank, which contains a complex aqueous solution and includes a metal in chemical form e.g. copper sulphate In sulphuric acid with copper anodes, together with an amount of gold In block form. By passing a carefully controlled electrical current through the solution held in the tanks a specific amount of metal (e.g. gold) is transferred from the anode on to the item to be plated.

The basic process is the same for all metals that can be electroplated eg. gold,silver,copper,nickel etc.

Using the Laws of Physics, the weight and therefore the average thickness of the metal being deposited can be calculated.

BJS now uses a third generation of digital computerised control systems for all of it’s electroplating to ensuring that their clients receive exactly the amount of metal that is required.

The information on all plating work is stored for 5 years, so when a client wants the same plating again, the system plates the work In exactly the same way as the earlier batch, ensuring consistency from piece to piece and from year to year.

By using state of the art equipment, you can be assured that your work has been monitored, controlled and tracked through all processing, to meet your specifictions and conforms to the International quality Standard ISO 9001:2008

Electroplating costs are generally based on surface area and thickness of the required deposit and the amount of preparatory surface work required.

A few examples and reasons for plating are given below:

Example 

 Plated     

Material Reason

Bathroom Fittings   

Hard Gold      

Cosmetic

Electrical Contacts

Silver

Electrical Properties

Gas Holders

Pure Gold

Corrosion Resistance

Tableware

Silver

Value Enhancement

electroplating

 

Rhodium Plating 

Rhodium Data Sheet

Rhodium is a very hard, silvery colour metal that is part of the Platinum Group of metals.

Widely used on high voltage switch gear, silverware, silver models, medals, white gold jewellery and top end furniture fittings to prevent tarnishing / corrosion as well as making the surface scratch resistant due to it harndess.

Being inert, it does have one major problem, should the item be damaged and require repair, the Rhodium Plate cannot be stripped from the more active base material without damaging the less precious substrate. 

This problem can be overcome using BJS’ unique “Rhodoplate” process, the only strippable Rhodium. If a Rhodoplated item needs repairing the Rhodium is easily stripped without affecting the base material. The repair is effected and the Rhodoplate is once again plated on to prevent corrosion.

Rhodium is plated from an acid solution which has poor throwing power. It cannot generally be used on items with deep cavities without some consideration to masking, jigging, pumping and shielding.

As it is an expensive process, areas that do not require coating can be masked with special masking tapes and paints.

Hard Gold Plating

Gold Data Sheet

Hard Gold Plating allows gold thicknesses up to 5 microns (M 10-6).

Known as “Hard” because there is a small amount of alloying which reduces it from 24ct  i.e. pure to 23.7ct. The  addition doubles the hardness of the deposit. Deposits are generally porous up to 2.5 microns and so if plating directly on to a tarnishable substrate, 3 microns (average) is recommended in order to prevent tarnishing of the substrate metal through the gold.

An intermediate layer of Bright Nickel is often used to protect the substrate metal from corroding and due to the nickel’s hardness, the sandwiching effect allows greater longevity of the gold top layer.

Nickel cannot be used on jewellery.

For gold deposits that are worn (jewellery) or item that are regularly handled (contacts, grab rails) we recommend a minimum deposit thickness of 1 micron.

Pure Gold Plating

Pure Gold Plating  allows gold thicknesses up to several millimetres.

Pure Gold Plating is used for industrial applications where either high purity of deposit is required and/or greater than 5 microns deposit are required. Pure gold is often used in place of Fire Gilding (mercurial gilding) which is no longer allowed in the EU, due to the very high toxicity of the process. The colour of the deposit being pure is identical to original Fire Gilding and can be burnished in a similar manner.

To visit the BJS Gold website click here.

Silver Plating


Silver Data Sheet

Industrial applications include high voltage switch and RF contacts and widely used decoratively on silverware and objet d’art.

Modern silver plating is made from bright plating solutions, which means the deposited silver mirrors the surface on to which it is initially deposited, i.e. a polished surface comes out polished and a satin (silk) finish remains satin.

Industrial silver plating thicknesses are normally prescribed by the client.

BJS’ standard thickness for decorative silver plate is 25 microns (average thickness). Depending on use and cleaning, this should last 30 years of normal wear.

Silver plating solutions are complex and have excellent macro throwing power, i.e. the deposit is fairly even from edge to the centre of a bowl.

All silver plating is tracked, monitored and controlled, ensuring that the mass of metal deposited is within 2% of predicted weight.