Gold Plating Services’ 24K Pure Gold Bath Solution is an extremely efficient (cathode efficiency 98%+), neutral pH, water-clear gold plating solution designed to produce a gold electro-deposit of 99.9+% purity to virtually any desired thickness. It is primarily used for surfaces in the medical, semiconductor, electronic, and PWB industries where soft, high purity gold is required. Due to the grain structure of this type of gold deposit, the reflective qualities of the surface will become noticeably matte with increased thickness.

This solution is fabricated with a purity and hardness of electrodeposited gold that meets Type III, Grade A specifications, as indicated in MIL-DTL- 45204D as follows:

Fine Gold Content -   Varies based on product size and type; recommend maintaining 2.5 g/liter
Purity -   99.9+ percent gold minimum (24 karat)
Hardness -   Knoop hardness < 90 (typically 55-60)
Density of Plate -   12.45 mg/in²/µ
Theoretical Coverage -*   1 gram of fine gold has a coverage of about 400 in² with the gold plated to an average decorative thickness. (A gold plating thickness of 8 - 10 micro-inches is a common thickness for decorative gold plating and exceeds the US Federal Trade Commission standards for non-jewelry gold plated items to be marketed as "gold plated.")

*This coverage is based on the assumption that all gold in the solution will be deposited. In actual practice this is not likely since the cathode efficiency diminishes with metallic content depletion, making the solution unusable at extremely low metallic content. As the solution is depleted, the cathode efficiency will diminish.

                           

Operating Conditions    

       Temperature -   120° - 150°F (optimum 150°F)

       Anode to Cathode Ratio -   2:1

       Anode -   Platinized Titanium or Bagged Graphite

       Voltage -   1.5 Volts (Voltage may vary if current driven)

       Current Density -   3 amperes per square foot, (20 ma/in²)

       Time to deposit 1 micron on 1 in² -   5.5 minutes at 3 ASF

       Replenishment -   Add Gold Replenisher Solution as needed

       pH (electrometric) -   5.8 – 6.4 (optimum 6)  

       Efficiency (Deposit Rate, Weight) -   115-mg/ampere minute

       Agitation -   Moderate relative cathode to solution movement       

       Filtration -   Continuous for large scale plating

       Hardness -   60 – 80 Knoop

       Shelf Life -   If stored at room temperature, properly sealed solution has a shelf life of ~2 years

 
If plating according to the above parameters, the following
amount of gold is required to plate 1 in² to the specified thickness (not including rack surface area):
0.2 micron (decorative plate) ~0.0025 g
0.5 micron (jewelry grade plate) ~0.0062 g
1 micron ~0.0125 g
 

NOTES:

To ensure consistency of deposit, the following operating conditions should be controlled.

METAL CONTENT- maintain within 20% of specified operating conditions.

TEMPERATURE- maintain within 5% of specified operating conditions.

PH- maintain within 5% of specified operating conditions. pH will slowly rise during operation. To lower the pH, use Pure Gold pH Control. Add slowly, as there is often a delayed reaction.

CURRENT DENSITY- maintain within 5% of specified operating conditions.

 

Contact us for more details on how to calculate deposit thickness.