July 24, 1981
COMMERCIAL ITEM DESCRIPTION
POLISH, METAL (SILVER)
The General Services Administration has authorized the use of this
Commercial Item Description in preference to Federal Specification
P-P-580.
This commercial item description covers a combination silver polisher-cleaner-tarnish preventive, for use on sterling silver and silver plated articles.
Salient characteristics:
The silver polish shall be a liquid containing a finely divided abrasive suitable for polishing silver and containing tarnish preventive material that remains on the silver after polishing. It shall be free from cyanides or any ingredients or solvents having a detrimental effect on silver or personnel.
pH. The polish shall have a pH of not less than 5.0 when tested in accordance with ASTM E 70.
Flammability. The polish shall have a flash point of not less than 140oF (60oC) when tested in accordance with ASTM D 92.
Caking properties. The separated abrasive material of the polish shall be soft and easily redispersed by stirring or shaking under the following conditions. Place forty ml of the well-stirred polished in a 75 ml cylindrical glass bottle, 1-1/2 inches in diameter, and centrifuge for 15 minutes at 1500 rpm. Examine the separated abrasive material with a glass rod to determine evidence of caking.
Cleaning efficiency. The polish shall have a cleaning efficiency of not less than 85 percent using the following method:
Material and equipment:
(a) Smooth, rolled, sterling silver panels, 4 x 4 x 1/16 inches. The silver alloy shall be 92 + 1 percent silver and 7.0 + 0.5 percent copper with a hardness of 30 to 50 on the Rockwell scale. The silver panels shall be suitably mounted on a firm base.
(b) A polishing machine having a 4-inch polishing head. The head shall have a rubber pad (1/4 inch min.) cemented to the head. A wrinkle free piece of billiard cloth shall be placed over the polishing head. The total weight of the polishing head shall be 4.0 + 0.1 pounds.
(c) 60o Specular Gloss Meter using ASTM D 523.
(d) A saturated solution of potassium sulfide.
Preparation of panels. Clean two silver panels using a jewelry’s rouge slurry. The cleaned panels shall have a 60o Specular gloss of 77 percent minimum.
Procedure. Record the gloss of the test panels. Tarnish the panels by immersion in the saturated potassium sulfide solution, maintained at 100o + 2oF for 2 minutes. Rinse in distilled water and blot dry. Apply 10 ml of the test polish to the polishing head and polish the panel for 114 strokes. Apply 5 ml more on polishing head and rotate the panel 90o, polish for 114 strokes. Repeat two more times. Rinse panels in distilled water and blot dry. Measure the specular gloss of the panels.
cleaning efficiency percent = gloss of soiled panel x 100
gloss of clean panel
Tarnish resistance. The polish shall have a tarnish resistance of not less than 85 percent using the following method.
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business