This was a pretty simple and straightforward panel replacement. The new valance is Nissan part number 79121-K2430. The original valance wasn’t actually rusty, but it was badly damaged in two places, and there were signs of rust starting in the seam where it’s attached to the boot floor and back panel. The first job was to remove it, which was done by drilling out the spot welds from below, across the horizontal seam, and by using a die grinder on the vertical seams at the ends. The spot welds on the horizontal seam were drilled right through the three layers….
The reason for this was so that the separated upper layer could be bent upward, so that any rust in the seam could be treated. Normally at this point I would fit a new rear panel as well, but it seemed a bit of a waste of a new panel, as the original rear panel was perfectly straight and undamaged. The surface rust in the seam was treated with Bilt Hamber Deox Gel, which works well, although a little slowly.
Whilst the rust was being treated, I took the opportunity to remove the surface rust from the rear of the spare wheel well. This is normally obscured by the rear valance, so it inevitably never has any kind of rust preventative coating on it. Once de-rusted, it was coated with some Hammerite Under Body Sealer. Unlike normal underseal, this stuff has Waxoyl mixed into it, so it never dries out fully and protects well against moisture and rust.
Once the rust was gone in the body seam, the upper layer was carefully bent back down and the new valance clamped in place. Welds were formed though the original holes made by drilling out the spot welds, and though new holes punched in the vertical seams on the valance. The welds were all then ground smooth. Finally the whole back end was stripped back to bare metal using a combination of a wire wheel in an air drill and DA sander.
Next on the agenda… the rusty windscreen surround.