Smartening up the lower bodywork

**Adrian** · by **Adrian** » Thu Apr 14, 2011 9:35 pm

Since 1994, the lower body has taken a battering and it was starting to show, so I thought I'd get the plastic skirts and inner arch covers off and make good before it gets too bad down there. In case anyone is thinking of doing the same (I highly recommend it if these areas haven't seen the light of day in a while) I'll mention how it all comes apart, in case it's not obvious, as I go along.

First, from underneath the car, I used a flat bladed screwdriver to lever out all the tabs holding the back edge of the sideskirt which is actually in two parts. (This post on Clubvauxhall shows how to remove the skirt in greater detail). Having popped all the tabs at the back, the skirt then simply pulls away outwards with a bit of effort. Probably best to start at one end to overcome the friction. A good heave out and towards you, then you're just left with the upper half bolted to the sill to remove.

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So, to reveal possibly even more grot, use a 10mm socket to undo the hundred or so nylon nuts securing the top half of the skirt to the car. At the front there's one plastic rivet. These have got a pin in the centre and the only way they'll come out without a fight is to hammer the pin right through with a blunted nail or similar. You do not stand much of a chance of recovering the pin afterwards, but it can be replaced with something that fits the hole or get a complete new plug.

With the top half of the skirt removed, it's clear that the leading and trailing ends of the sill have acquired a nasty gravel rash. This needs attention before it holes through.

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Inside the rear arch, the plastic guard towards the front of the car needs to come off. This just requires the slide clip to be levered off then the whole panel pulls out. There are two lugs holding the guard to the body via two big holes and in my case water has got in from behind and rotted the lower edge of the inner arch and gone in through the holes on the inside.

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This area I will be sandblasting along with the other rusty bits. Chief among these is the lip of the arches, front and back, where the unprotected (thinly painted) edge has allowed corrosion to migrate in under the paint and head outwards towards the visible part of the arches. The front arch guard comes off with a couple of nylon nuts, plastic rivets and one screw into the lower edge of the front bumper. The guard needs pulling down off the threaded posts at the back while pushing up and away from the lip of the arch. There's a similar arrangement at the back to remove the rearmost guard and gain access to the internal section above the bumper. Once all the guards are off a good clean with hot soapy water is called for to remove all traces of accumulated muck.

I've got a cheapo (Aldi) spot sandbalster attachment for a compressor and it works just fine in these small areas although regular aluminium oxide paper and elbow grease would be enough to remove flakey paint and loose rust. Hopefully if it's caught early enough the rust won't have made it round to a visible part so it will be possible to overpaint and look OK (unless you get underneath and have a critical look).

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A bit of masking comes in handy to keep the aluminium oxide from taking too much paint off and the rusty bits start to dissapear leaving a reasonably smooth surface for final treatment.

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In my case, I decided to use POR15 which paints on to metal directly and is a special formulation that cures chemically rather than using volatiles. This creates a gas impermeable layer that prevents further oxidation of the steel. I bought a kit from Frost UK which has a small tin of POR15 plus a degreaser and metal prep that neutralises any remaining rust. This starter kit is the ideal size for doing the job I'm describing here.

Here I've brushed it into the overlap in the door frame. The leading edge of the rear section is poorly protected by the standard paint job and POR15 goes on thick enough to build up flush with the edge. I think this stuff is brilliant.

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Using the black (it does come in other colours) it almost looked stealth enough to not need a topcoat on my colour, but I had a matching rattle can, and (on a hunch) dusted it over the last (third) coat of POR15 just as it was going hard. Magically the paints sort of combined and I got the dark turquoise with a mica shine that blended straight away with the surroundings. Lucky me! Somehow it picked up the gloss from the (very) glossy black stuff without the need for any lacquer although I might revisit this one day when I address the myriad of stone chips.

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When putting the rear plastic guard back on I used some black Sikaflex EBT to seal the edges where it had rusted away. This stuff is flexible and waterproof and bonds well. The panel wasn't a very good fit so I ran a bead around all the edges (apart from the bottom edge to let it drain). A good rub down with bumper gel to restore the black finish on the plastic parts before re-fitting and the job's done.