Project Ninety: Part 13
A new door is the only real answer to white-spot corrosion, but fitting one can be a complex job, as Ed Evans explains
A new door is the only real solution to whitespot corrosion – Ed Evans shows how to build and fit one
Last month we looked at how to replace a Defender or earlier Ninety/ One Ten tail door. Now we’re replacing the side doors, which is a very different job involving more equipment being built into the shell and a more involved alignment procedure.
As with the tail door, barring accident damage, the most common reason for fitting new doors is corrosion and, on the side doors, there are two main concerns. The aluminium door skins of all pre-tdci (Puma) models typically corrode along the bottom, producing the unsightly white corrosion deposits. This electrolytic corrosion is produced by the combination of moisture and the close proximity of the inner steel frame to the outer aluminium skin. The same applies higher up, just below window level where the skin corrodes in the proximity of the upper internal steel structural section. The second area of concern is the upper internal steel section which can rust severely, depriving the door of its rigidity and strength.
As we said last month, there is no lasting solution to this aluminium corrosion and the only option is to replace the door. That, of course, involves dismantling the parts from the old door and building them into the new one, and ensuring the new door is correctly aligned in respect of the door frame and panels, the door seals and the latch striker on the B-post.
Through the life of these vehicles, part specifications have changed, sometimes only subtly, and original fitments are not always available. This can demand a bit of patience and forward thinking when building old parts into a slightly later-specification door, as is the case with our 1989 Ninety here.
The new doors used here have been painted before assembling the internal parts, and that’s always the best option because it means less work for the paint shop in masking off (and thus a lower bill), and it also means that the door edges and internal areas get properly painted.
Once again, we’re in the Britpart workshop with Steve Grant, first salvaging the parts from the old doors, then transferring them into the new shells and aligning them to the body, together with new seals. Obviously, the job is identical on each side door, so this feature deals with the left (UK passenger) side door.