TAILGATE RUST

1 Rust around the wiper spindle is pretty rare – we can only assume the paint was chipped when the new wiper motor was fitted. Whatever the case, it needs to be stopped before it spreads to the lower tailgate.

2 After cleaning off the worst with a wire brush in a grinder, we sanded the paint back with 400-grit. There is rust pitting that will need a touch of body filler – use a mini sandblaster to really clean the pits and give them a coat of Kurust.

3 We rubbed the paint down with 600-grit wet-and-dry and water to feather the paint back and prevent an ‘edge’. We then applied a touch of body filler to the pitted areas, which will be rubbed smooth with 400-grit and water.

4 On a warm day, the filler dries in 30 minutes. We got it right first time without having to add more. We then masked it and sprayed on some aerosol primer filler, before flatting it with 800-grit and water.

5 After removing the masking, everything was dried thoroughly and remasked. We sprayed on three thin coats of regular grey primer, before allowing it to dry and flatting it again – time taken here means a perfect finish.

6 Rather than use the Halfords paint again, we paid less than £25 for some Crimson Red (with lacquer) from BMW. While metallic paint always needs lacquer, solid colours don’t – you just end up complicating the job.

7 Masking is very important to avoid overspray. We back-masked – ie, folding the edge of the tape backwards for a ‘soft’ edge to the paint – into the tailgate swage line.

8 We applied the paint evenly in several thin coats – the BMW paint goes on superbly. We applied three double coats (back and forth) with five minutes in between. From the can, the shine was excellent, but it dulls after an hour or so.

9 Refit the wiper and leave the paint for a week to harden, after which it can be lightly flatted with 3000-grit and polished back with T-cut or a light cutting compound. The previous rusty scab has now gone.