E-Coating Corrosion Protection
Many of you have asked us if it is possible to have the body E-coated. Building
a Dearborn Deuce Convertible TM represents a significant investment and protecting
that investment from corrosion is a major concern for all of us. As your
body is being assembled by a major Detroit OEM using advanced OEM jigs and
equipment, it is only fitting that we offer you OEM corrosion protection.
We thought this would be a straight forward process, but much to our surprise
we found that the OEM suppliers of “full body E-coat immersion” are
unwilling to interrupt their production line to dip our bodies. These facilities
are immense and they treat thousands of car bodies and components a day.
It is not practical or economical to interrupt their production
In order to dip our body in an E-coat bath, you must have at least three
separate tanks large enough to handle the body and a robotic conveyor and
crane system to manage the flow of work. Why three separate tanks? The first
tank is used to clean and pre-treat the body, the second tank is used to
apply the E-coat and the third tank is used to rinse and recycle excess material.
In addition, the facility must also have a baking oven large enough to handle
the body.
We found such a facility in Toledo, Ohio that does
specialized work for Ford’s pickup truck program. Toledo is a long
way from Detroit and the transportation costs are significant.
Nevertheless, we are offering a program that should
satisfy everyone interested in achieving the ultimate standard in corrosion
protection: the passenger and driver’s side doors, deck lid and the tonneau cover (all of these
panels have an inner and outer skin), and full immersion of your body in
an E-coat paint bath. The cost of this option is inclusive of “white
glove” handling and transportation to and from Toledo, Ohio, special
crating and fixturing and all additional labor costs connected therewith.
Cost $2,500.00.
Exactly what is E-Coat?
E-Coat is an electrically-applied paint coating. It
is also known as electrocoating, electronic coating, electronic painting,
and electro photo coating. E-coating was developed originally for the automotive
industry because it is economical and provides superior coverage, adhesion,
and corrosion resistance. It
coats any metal (aluminum, zinc, brass, steel) that conducts electricity.
Here is how E-coat works. The parts to be E-coated
are first cleaned and treated with a zinc phosphates conversion coating.
The panels of your Dearborn Deuce Convertible TM are moved to Oakley’s
assembly area with a thin film of oil remaining on each panel from the
stamping operation. The oil protects the freshly stamped steel panel from
rusting during shipping and assembly.
The parts to be E-coated are then attached
to metal racks or placed in a coating fixture. In our case, both the hemmed
components and your Dearborn Deuce Convertible TM body each use a
special coating fixture that is lifted by crane and put onto a conveyor
carriage system. The bodies are placed on a system designed to carry truck
frames.
The parts are immersed in an E-coat paint tank. A direct
negative electrical charge is applied to the carriage and the body and
parts are “electrically
charged.” An opposite direct positive electrical charge is applied
to the paint bath.
For those of you who love the details, this process
is known as cationic E-coat and is used to provide a more corrosion-resistant
film than the more common anionic E-coat process. The paint bath is filled
with Cathodic Epoxy PPG 8000 E-coat. Epoxy based E-coats are used in environments
where corrosion protection is paramount. Your “charged” parts
attract the oppositely charged paint particles. As the paint is deposited
it begins to act as an insulator and deposition slows, stopping at a precisely
predetermined thickness that is governed by the amount of voltage applied
during the process.
Even though deposition may have slowed or may be complete on one area on
the surface of the part, deposition will continue on any uncoated or incompletely-coated
area of the part until complete coverage is achieved.
This is a very important point, especially when a hemmed
part is involved. For example, the doors, deck lid and tonneau cover on your convertible
have an inner and outer skin. Once the part is hemmed (joined together),
conventional spraying obviously cannot reach the inside surfaces of the outer
or inner skins. Think about the inner door of a convertible when it rains.
No matter how tight a seal is applied to the window glass, some moisture
will always seep into these openings. Small hardware parts such as mounting
and tapping plates as well as door and deck lid hinges are often treated
as an “after thought,” but these items are especially vulnerable
to corrosion and need to be protected.
When a part is dipped in an E-coat bath, the E-coat
is electrically drawn through the drainage or weep holes and other openings
in the hemmed parts and adheres to the inside surfaces. This adhesion process
will continue until the entire interior surface is uniformly coated. Conventional
spraying of the most advanced primers leaves uncovered areas and over time,
rust and corrosion can occur.
In addition to your convertible’s hemmed parts, there is another very
important area that should be treated---the inside of the square tube sub-frame
components. Your convertible’s steel body panels are attached to an
inner sub-frame made from square steel tubing. Conventional spray techniques
can only reach a few inches inside the very end of the tube. The E-coat dipping
process will cover the entire inner surface of each tube with a protective
coating.
After your parts are coated, they are rinsed, and any
undeposited paint solids are reclaimed and recycled. The final step is to cure the E-coat
by baking. Your parts are taken by the conveyor system to a baking oven for
20 minutes. Heat treating causes the molecules of the paint film to
crosslink, which further adds to its strength and durability.
As you can see, the very nature of the E-coat process produces a complete
and uniform protective coating. We have specified matte black E-coat as the
most appropriate color for your body.
As a protective coating, E-coat is an increasingly
popular alternative to other protective coatings such as electroplating,
lacquering, painting, anodizing, and powder coating.
Other benefits E-Coat offers are:
-
Cosmetic Appeal. E-Coat paint applies a super-even finish,
no dripping, no pooling and no gaps.
-
Corrosion Protection. All parts are
coated evenly inside and out. Complex parts can be coated even after assembly.
-
Unbeatable
Durability. Withstands the most rigorous salt spray, adhesion, dialectric,
acid resistance, and U.V. tests.
-
Super Adhesion. Because of
the very nature of the E-Coat process, a thin coat can be complete, uniform,
tough, and attractive, while still maintaining close engineered tolerances.
E-coat is standard OEM practice: it is corrosion-resistant, chemical-resistant,
temperature-resistant and U.V.-resistant. E-Coat is much more effective than
even currently available etching primers. Traditional spray techniques
cannot compare to the quality and durability of an E-coat primer.
