Tender loving car

Aidan Wojtas
Car body repair

Just like fixing a rip in your favourite pair of jeans, repairing cars also requires a bit of TLC to avoid being a fashion disaster. Fortunately, working on your car is a long way from threading needles on a sewing machine.

This issue we repair a bumper that went rabbit hunting at 100 km/h. The owner’s car has creases in the right places again, and fixing it is much more fun than ironing.

If you’re DIY-ing, you first need to be realistic about the kind of issue you’re trying to solve. If you now have a port window where you once had a door, visit your local Pick-a-Part. They’re especially good for cars ten years or older. For modern parts, a great source is New Zealand Car Parts. Recently I picked up some side skirts for my car (it’s a girl, you see) for $95 as-new.

Ideally, the problem will be a hole or dent no larger than your fist. Tears in bumpers are easy to fix, and our rabbit kindly gave us a working sample.

If you’re repairing a flexible part, such as a spoiler or bumper, fibreglass will give it original strength without cracking when flexed. Otherwise, bog (also known as “body filler”) is perfect for fixing rust spots smoothly, or helping with dents on metal. Our bumper was torn in the middle on the lower lip, so fibreglass behind the lip will make it as good as new.

Your choice of primer (the base coat applied before any coloured paint) depends on the surface you’re spraying. Fibreglass requires a plastic primer to adhere to the surface, whereas zinc-based primer is a must for rust. Rust loves zinc, almost as much as it loves 1987 Honda Accords. But I hope your car is still mostly metal – rust is not a fashionable colour. I bought a plastic primer from Road & Track (Repco also have reasonable quality paint). While I was there, I also had my paint matched up – costly, if you have the misfortune of owning a pearl-white car.

First of all, clean the area thoroughly. I like Bug & Tar remover. Then prepare the surface with 80–120 grit sandpaper to get the paint and rust removed rapidly. Once the worst is gone, move quickly to a 200–240 grit paper so that you don’t make coarse marks in the surface – they can be hard to remove or fill in later. You may even want to skip the rough paper. I used a polishing sander and 240 grit paper to quickly sand the area around the split lip. A sander gives good control when working with plastic and fibreglass. Make sure any rust is gone from the diseased area, and lightly sand around the vicinity so the paint is flush with the surface.

Prepare the fibreglass, taking time to follow the instructions. A fibreglass kit, available from Repco or Super Cheap Auto, will give you everything you need for about 30 to 40 dollars. The latex gloves are essential. Make sure all fibreglass strands are covered with resin, even if they aren’t going where you want them. It’s much easier to hack-saw or sand hard fibreglass than to remove soft fibres if no resin was applied. I also put resin in all the tiny cracks that fibreglass wouldn’t fit into, as it hardens on its own, and is near impossible to tell from the original once sanded and painted.

Bog is much simpler. But be careful with the hardener. Too much and the bog will firm up quickly yet crack later. Too little and you’ll be renaming the saying to “watching bog dry”. The bog should turn slightly pink. (If I was a real fashion writer I’d call it pale salmon.) Once you’ve filled in the hole, use a putty blade to smooth the bog, but allow it to stand out a little so you can sand it back to be flush with the surface.

Bog normally takes an hour to dry, and for my fibreglass to harden properly I left it overnight. Once it is completely dry, you’ll be able to manipulate it by sanding very easily. This is the hardest part, and it has everything to do with patience and nothing to do with skill. Sand flat, and if you have any little pock marks or cavities, Repco sell a “tube putty” that can fill in any blemished surfaces. Again, allow at least an hour to dry, preferably more.

Spray on your primer once the bog or fibreglass is finished, again making sure the area is clean before you start. Primer dries quickly, normally within 15 minutes in the sun. Just ensure you have a smooth coat and there are no runs in the paint. A few coats will do the trick.

Now you’re up to the real painting. If you have an expensive paint, you might like to paint on a cheaper base coat first, using a similar shade to the real paint. (I used Super White II from Repco as my base coat.) That way you don’t have to waste expensive paint trying to hide pink bog or yellow fibreglass.

Once you’ve sprayed evenly and smoothly, and the colour has come through strongly, you’ll be ready to think about sanding with fine sandpaper (such as 600 grit) and adding more coats. This is handy if you made a few mistakes, and it will give a strong layer of paint. Or you might be ready to finish with a top coat for a gloss finish. Gloss paint is a pain, but it can make the difference between an off-white and the real white of your car. It can also run very easily, so take your time.

Well done – you’re probably looking back and admiring your work already. Hopefully it doesn’t look like the first time you discovered hair gel (I’d recommend the Wearable Arts for worst cases). But it’s experience that’s valuable. Soon you’ll be looking for all the rips in your petrol-drinking “jeans”. You’ll be proud of your own mended fashion.

Aidan Wojtas is an ex-Southern man who, after his move to the Capital, severed most ties in order to embrace city living. Despite the Ben Sherman shirts, hints of the Mainland still reveal themselves ... the DIY, the grunty cars, and the smug look every time Canterbury wins. He works as IT manager of a telecommunications company in Wellington.