you need longer tool cover life, place cotton, Dacron,
contact plating shop equipment. It will remain useful
or cotton-Dacron tubegauze sleeving over the cotton
even if changes in the workload require smaller or larger
batting. You also may use Dacron batting, Pellon, and
units to supplement it.
treated Scotchbrite to cover plating tools.
Plating Tools
APPLICATIONS
Contact plating tools consist of a stylus handle with
The contact plating process is a rapidly expanding
a conductive core, which is insulated for operator
field. When used to deposit a corrosion-resistant
safety, and an insoluble anode normally of high-quality
coating, electroplating has shown enough success to
graphite. Since considerable heat is generated during
permit almost unrestricted use. The vast field of
plating operations, there must be a means of cooling the
possible applications in the repair of worn or damaged
plating tool. The handles of plating tools have cooling
parts of high-speed rotating and reciprocating
fins to dissipate heat, but you may need to cool larger
machinery is limited only by the knowledge and skills
tools with plating solution or water. Graphite anodes are
of the operator in areas where plating is allowed.
brittle and are not practical where a very small diameter
Electroplating applications are classified as follows:
anode is required. For plating holes less than 1/2 inch
in diameter, or narrow slots and keyways, anodes made
Class 1:
Plating used for decorative or
of 90 percent platinum and 10 percent iridium material
corrosion prevention functions only
are recommended.
The equipment manufacturers offer removable
Plating on parts to restore dimensions
Class 2:
anodes in a wide range of standard sizes and in three
on surfaces that remain in static
basic shapes: cylindrical or convex to plate inside
contact with gaskets, O-rings, or other
diameters, concave for outside diameter's, and flat or
metal surfaces
spatula shaped. You also may purchase graphite
material to manufacture special tools.
Plating on parts that make rubbing or
Class 3:
intermittent contact with other plated
Solutions
or unplated parts, including electrical
contacts except those in class 3A
The solutions used in contact plating include
preparatory solutions used to clean and activate the
Class 3A:
surface to be plated, plating solutions used to deposit
Plating on rubbing contact surfaces of
turbines, reduction gears, electric
pure or alloy metals, and stripping solutions used to
p o w e r generating units, main
remove defective plating. These solutions are
propulsion shaft seals, steam valves,
manufactured and sold by the process equipment
manufacturers. You can use solutions of any trade name
and other sliding contact areas when
specified
if the deposits meet the applicable plating specification
and if they are certified by procedure tests. However,
do NOT use plating and preparatory solutions of
Plating on parts under the cognizance
Class 4:
different manufacturers for the same plating job.
of the Nuclear Propulsion Directorate
For plating operations, pour solution into a shallow
Refer to MIL-STD-2197(SH) for plating appli-
glass or plastic dishes or beakers for dipping, or use
cations for each of these classes.
them in a pump that dispenses solution through the tool.
OPERATOR QUALIFICATION
Plating Tool Coverings
Operators will be qualified by the quality assurance
The most common tool covering is cotton batting
function of the plating activity before being permitted
of surgical grade U.S.P. long fiber, sterile cotton. It is
to perform contact electroplating.
fastened to the anode to hold and distribute the solution
uniformly. You can use cotton batting alone for jobs that
Before examination for qualification, each pro-
involve a few short preparing and plating operations, or
spective operator will successfully complete a manu-
to ensure maximum tool to workpiece contact for
facturer-sponsored training course or one provided by
plating in corners or on irregularly shaped areas. When
the plating activity. The course shall be approved by the
12-9