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Chrome Plating
Step 1:
Stripping
When it comes to first-class chrome plating, preparation is everything. A
careful, complete prep job is the most important step in the chroming
process, necessary to produce a clean, absolutely bare surface for the new
chrome treatment to adhere to. This includes removing any old chrome,
nickel or copper plating, as well as any paint or other coating that may
have been applied to the part. |
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Step 2: Polishing
After the part has been thoroughly stripped and cleared of any old
coatings, it is polished to ensure a smooth, blemish-free surface. Chrome
is essentially a shiny reflection of the surface of the metal underneath—if
that bare metal has any flaws, uneven surfaces or other imperfections,
these will be visible in the final product. DGM does all its polishing the
old-fashioned way, sanding the part with various grades of sandpaper,
working from a very rough to a very fine grit, until a smooth, even
surface remains. After polishing, the part is thoroughly cleaned again to
remove any residue—the first of many cleanings the piece will undergo
during the chroming process. This constant recleaning after each step is
one of the things that distinguishes a good chrome job from a poor one.
Even the smallest bit of foreign debris or residue on the base surface can
blister or pit the final chrome coating. |
Step 3: Electroplating
Once the metal has been polished to a mirror finish, it’s ready for
electroplating. Electroplating is the process of passing an electrical
current through a piece of metal suspended in a liquid solution of metal
ions, in order to make two different metal materials bond to each other
and create a hard coating on the part being plated. The industry standard
for chrome plating is triple-plated chrome, which typically means that the
part is first plated with copper, then nickel, and chrome on top. DGM goes
a few steps further with its plating process, applying a minimum of five
protective layers (nickel, copper, a second copper coating, a second
nickel coating, then, finally, chrome) for maximum corrosion resistance
and the brightest shine.
Copper is a malleable metal that can help to cover up any minute
imperfections that the polishing process might have left behind, which
explains why two doses of copper are applied early in the process. The
first copper coating is actually an alkaline copper solution. After this
coat is electrochemically applied, the part is set to dry and then
rebuffed by hand until it looks like a new penny. Then the piece is
cleaned and sent off to the dunk tanks for a second copper plating—this
one acidic, not basic—and cleaned again before a dip in the tank of
nickel solution. This last nickel-plated layer is actually what produces
the shiny reflection in the final chrome piece.
After yet another cleaning the part is at last dunked into an inky black
chrome bath. Why black? DGM uses hexavalent chrome, which in liquid form
resembles a murky, coffee-like fluid that looks anything but shiny. There
are two types of chrome plating used in the motorcycle aftermarket:
hexavalent chrome and trivalent chrome. Hexavalent chrome produces a
brighter, show-quality finish; trivalent is lower-quality chrome plating
that is usually less expensive but not as durable. The tank is
electronically charged to adhere a very thin layer of hexavalent chrome to
the metal. When the metal piece is first lifted from the chrome vat, it
appears as though something has gone terribly wrong: The piece has a
distinct yellowish tint, as if it has been afflicted with jaundice. Not to
fear—one last quick chemical bath and voilà, the chrome piece emerges
crystal clear. |
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Step 4: Final Inspection and Buffing
After the chromed piece has finished curing, the final step is a close
inspection by DGM. If any blisters, waves or other imperfections are
detected, the piece is sent back for a complete rechroming until it is
flawless. |
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