Underbody sealer

CORROSION PREVENTION AND SEALING

77-4-8

SEALING

Underbody sealer
Underfloor areas and sill outer panels are treated with a Plastisol PVC underbody sealer. This material is not suitable 
for re-treatment. When repairing areas of underbody sealer, strip the factory-applied underbody sealer back to a 
suitable break point. Ensure that a clean metal surface is exposed and that the edge of the existing sealer adheres 
soundly to the panel.

Apply new underbody sealer between primer and surfacer paint operations. Apply seam sealer as necessary before 
application of underbody sealer. Ensure that blanking plugs and grommets in the floor pan (except those used for wax 
injection) are fitted before underbody sealer application. Refit any heat-fusible plugs which have been disturbed in 
repair with the aid of a hot air blower, or replace with rubber grommets.

caut : Ensure that suspension units, wheels, tyres, power unit, driveshafts, exhaust and brakes (including all mounting 
points) are shielded prior to application of fresh underbody sealer.

Underbody wax
The underbody wax must be reinstated following all repairs affecting floor panels. The wax is applied over paints and 
underbody sealers.

caut : Remove old underbody wax completely from a zone extending at least 200mm beyond the area where new 
underbody sealer is to be applied.

Engine bay wax
Reinstate all protective engine bay wax disturbed during repairs using an approved material.

Where repairs have involved replacement of engine bay panels, treat the entire engine compartment including all 
components, clips and other fixtures with an approved underbonnet lacquer or wax.

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 approved, 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 dewaxing
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 liquified.

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 300mm from panel surfaces.

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.