Before fitting a new front wing it is essential that the inner wing is in sound condition and any repairs must be undertaken before the wing is fitted. The main areas of concern are:

• condition of the inner panel
• the enclosed section between wing and bulkhead above the sill
• the triangular reinforcement box section

Before starting to replace the rusted sections disconnect the batteries and ensure that the carpets, panels and any other inflammable materials are removed from the foot-well inside the car. Also ensure that the wiring loom will not be damaged when welding or cutting. As welding and cutting will be necessary basic fire safety precautions should be observed. Where possible an angle grinder with a metal cutting disc is recommended for cutting new and old panels to minimise distortion.

The closing panel which protects the area between the wing and bulkhead above the sill can, after some years of exposure to road salt etc, rust allowing moisture to penetrate causing unseen weakness in the structure. When the wing is removed the extent of the rust damage can be assessed. Fortunately, repair sections are available which include a new flange complete with captive nuts for the closing panel. These are 'handed' and you should buy either left or right-hand side as required. The flange extends across the flat top of the bulkhead under the wing at this point. It is important to renew this flange because a rubber seal will be fitted later to keep out moisture. Because of its inaccessibility, it often goes unnoticed and may be missing.

The reinforcement box section helps to maintain the rigidity of the front of the car and so should be in good condition. Unfortunately due to its position, it traps road dirt and moisture and can rust very badly on the upper surface if left unprotected. Before fitting the new section it is a good idea to give it a coat of paint on the inside - but do not paint any of the flanges that will be welded. The inside of the panel can be treated with anti-rust wax when the job is complete and the extra paint will be a bonus. Start by drilling out the spot welds that secure the old box section and remove it. The inner panel should be sound following the inner panel repairs described above. Next fit the new box section into place. Some dressing will be necessary so blind fasteners will be useful during this process. The rear of the box section is shaped to fit inside the bulkhead but some trimming and dressing will be necessary. Once you are happy with the fit plug weld the box section into place. Plug weld at one inch (25mm) intervals along the flanges, then weld the bulkhead repair panel into place and finish by welding the joint where the box section joins the bulkhead.

When the inner wheel arch repairs are complete seal all seams with a good seam-sealer to prevent moisture getting in and causing rust to start again. The final finish will depend on the end result required. A thick coat of underseal will give good protection but you may want a finish in body colour and so a coat of stone-chip paint may be preferable followed by body colour.

'Kingpin'