Plating Process

Pictures and descriptions by Gary Salstrom, record plating manager at RTI.                                                                                

Step One

Step Two

Upon receipt, the lacquer must be prepared for plating.

The lacquer is then soaked in a mild detergent to clean oil residues from the surface.

Step Three

Step Four

After thorough rinsing with deionized water and a surface treatment with Stannous chloride, the lacquer is sprayed with customized silver (made from scratch at RTI) to make the surface electrically conductive.

The lacquer is then mounted on a copper hanger and placed in a nickel sulfamate plating bath. RTI uses low temperature and low amperage to ensure proper duplication of the groove walls.

Step Five

Step Six

After the master is made (14-16 hours), it must be prepared for plating to make the mother. After a quality control check of the mother, a stamper must be made to press the LP.

The nickel mother is placed into a customized rotary plating tank to make the stamper.

Step Seven

Step Eight

The stamper must be carefully removed from the mother.

To keep the LP surface free of surface roar, the back of the stamper must be sanded to a near mirror-like surface.

Step Nine

Step Ten

The stamper is then centered, trimmed, formed, and washed before being delivered to Q.C. The stamper is then closely inspected before being passed on to the pressline.

Test pressings being pressed on a SMT record pressing machine at RTI.


Plating Diagram


Shown here are enlarged characterizations of the recorded grooves starting with the master lacquer through full "process plating" to the final pressed record.

M a s t e r L a c q u e r

A music source is fed to a mastering lathe and the modulated signal causes the grooves to be cut in the master lacquer. The master lacquer, although slightly larger, appears very much like a finished LP without labels. The master lacquer is then put in electroplating, where the metal master is made (to eliminate groove deterioration).

M e t a l M a s t e r

From each master lacquer only one metal master can be plated, from which the metal mother is plated.

M e t a l M o t h e r

Metal mothers can be "pulled" from the one metal master from which metal stampers are plated.

M e t a l S t a m p e r s

Metal stampers (the manufacturing press discs) can be "pulled" from each metal mother and from each stamper approximately 500 to 1,000 finished records can be pressed.

P r e s s e d L P R e c o r d

Posted by Acoustic Sounds on 02/27/2002 at 3:47 PM | Categories: General