Underbody Restoration

Underbody Restoration with FERTAN

Removal of rust and corrosion

  1. Firstly, the chassis should be cleaned of loose dust, dirt, oil, grease and silicon contamination. A pressure washer is recommended for this.
  2. FERTAN Rust Converter is then applied to the chassis while it is still wet, by means of a spray gun or possibly by underbody gun, at a pressure of approx. 15- 43.5 PSI. The remains of the old underbody protection should be removed as far as possible. This also applies to the remains of PVC treatments, which are often used in the area of engine mountings. Treatments and layers which are securely attached to the underbody may be allowed to remain, because in general no corrosion is present here. However, it should be carefully checked that there are no areas where the rust has lifted areas of the paint and penetrated under it. When restoring a classic car complete removal of the old underbody protection is always recommended. The complete removal of all coatings (e.g. underbody protection) can be carried out via dry ice pressure-spraying. Dry ice pressure-spraying has proven itself as the best treatment preparatory to FERTAN Rust Converter treatment itself, because the removal of the old layers can be controlled very accurately, and no pollutants find their way into the pores of the metal. The FERTAN Rust Converter which has been applied should be allowed to act for at least 24 hours, during which time the vehicle may be used as normal, except on salt-treated roads.
  3. Before the final protection is applied, if possible, within 6 months of applying the FERTAN Rust Converter, the chassis should again be thoroughly washed with water. If final underbody protection is not being used, the FERTAN Rust Converter treated underbody is protected from further corrosion by the iron tannin treatment for a period of 6-12 months.
  • For historic vehicles that are only used in summer, a coating with the FERTAN Underbody protection wax would be sufficient.
  • In situations where heavy demands are to be placed on the treated panel (for instance year-round usage) FERTAN Stone guard Protective Underseal should be used as a base coat but always take care to treat the overlapped joints with FERTAN Underbody Wax after the treatment. The Stone guard Protective undercoating is over paintable.

It is very important to understand that on vehicles which are subjected to flexing or heavy duty as part of their construction (e.g. convertibles), or normal service (e.g. 4x4s), it is recommended always to use a non-hardening coating such as FERTAN Underbody Protection Wax as final layer. This flexible coating will almost never tear – unlike the coatings that harden. If cracks appear in the underseal coat, that’s the ideal breeding place for new corrosion!

To apply the Rust Converter use either the Cavity- and underbody protection gun 8011520 or Professional Pressure Gun 8011020.
To apply the Stone guard Protective Underseal or the Underbody Protection wax use either the Cavity- and underbody protection gun 8011520 or Professional Pressure Gun 8011020 or the Aerosol version.



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