Corrosion Prevention - MG MG6 Series 2011 Service Manual

Body Repair

Corrosion Prevention

Factory Treatments
During production, vehicle bodies are treated with the
following anti-corrosion materials:
• A PVC-based underbody sealer which is sprayed onto the
underside of the main floor, rear floor and the rear wheel
arches.
• An application of cavity wax which is sprayed into the sill
panels, side member extensions and the lower areas of
the door panels.
• A coat of protective wax is applied to areas of the wheel
arch not covered by the liners. Whenever body repairs
are carried out, ensure the anti-corrosion materials in
the affected area are repaired or renewed as necessary
using the approved materials.
Precautions During Body Repairs and Handling
Take care when handling the vehicle in the workshop.
Underbody sealers, seam sealers, underbody wax and body
panels may be damaged if the vehicle is carelessly lifted.
Proprietary Anti-corrosion Treatments
The application of proprietary anti-corrosion treatments, in
addition to the factory-applied treatment, could invalidate the
Corrosion Warranty and should be discouraged. This does not
apply to homologated compatible, preservative waxes which
may be applied on top of existing coatings.
Fitting Approved Accessories
When fitting accessories ensure that the vehicle's corrosion
protection is not affected, either by breaking the protective
coating or by introducing a moisture trap.
Do not screw self-tapping screws directly into body panels. Fit
suitable plastic inserts to the panel beforehand. Always ensure
that the edges of holes drilled into panels, chassis members
and other body parts are protected with a suitable zinc rich
or acid etch primer, and follow with a protective wax coating
brushed onto the surrounding area.
Do not attach painted metal surfaces of any accessory directly
to the vehicle's bodywork unless suitably protected. Where
metal faces are bolted together always interpose a suitable
interface material such as weldable zinc rich primer, extruded
strip, or zinc tape.
Steam Cleaning and De-waxing
Due to the high temperatures generated by steam cleaning
equipment, there is a risk that certain trim components could
be damaged and some adhesives and corrosion prevention
materials softened or liquefied. Adjust the equipment so that
the nozzle temperature does not exceed 90° C (194° F). Take
care not to allow the steam jet to dwell on one area, and keep
the nozzle at least 300 mm from panel surfaces.
Version 2.0
DO NOT remove wax or lacquer from underbody or
underbonnet areas during repairs. Should it be necessary
to steam clean these areas, apply a new coating of wax or
underbody protection as soon as possible.
Maintenance Inspection
Carry out the following operations to check bodywork for
corrosion:
• With the vehicle on a lift, carry out visual check of
underbody sealer for damage.
• With the vehicle lowered, inspect exterior paintwork for
damage and body panels for corrosion.
Note: If the vehicle is dirty, it will need to be washed prior
to inspection of bodywork.
The checks described above are intended to be visual only. It
is not intended that the operator should remove trim panels,
finishers, rubbing strips or sound-deadening materials when
checking the vehicle for corrosion and paint damage.
1. With the vehicle on a lift, and using an inspection or spot
lamp, visually check for the following:
• Corrosion damage and damaged paintwork, condition of
underbody sealer on front and rear lower panels, sills and
wheel arches;
• Damage to underbody sealer. Corrosion in areas adjacent
to suspension mountings and fuel tank fixings.
The The The presence presence of of of small presence
Note:
underbody sealer sealer is is is acceptable, acceptable, providing
underbody underbody sealer acceptable,
not expose expose bare bare metal. metal.
not not expose bare metal.
Pay special attention to signs of damage caused to
panels or corrosion protection material by incorrect jack
positioning.
Warning: It is essential to follow the correct jacking and
lifting procedures.
2. With the vehicle lowered, visually check for evidence
of damage and corrosion on all visible painted areas, in
particular the following:
• Front edge of bonnet.
• Visible flanges in engine compartment.
• Lower body and door panels.
Rectify any bodywork damage or evidence of corrosion
found during inspection as soon as is practicable, both to
minimise the extent of the damage and to ensure the
long term effectiveness of the factory-applied corrosion
prevention treatment. Where corrosion has become
evident and is emanating from beneath a removable
component (e.g. trim panel, window glass, seat etc.),
remove the component as required to permit effective
rectification.
Collision Repair
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