How to paint a car: Can you do it yourself?

Let’s get something straight right from the off: Painting a car at home is not something we – or anybody else – can teach you in an online article.

It’s a huge skillset that takes years or even decades to perfect and it’s the reason having a car painted professionally costs as much as it does.

But the reality is that many people have painted cars in their home garage or even car-port, and have been happy enough with the results.

So, is it worth giving it a go? If you’re handy, know how a spray-gun operates, have lots of patience and a better than average dollop of confidence going in, you might, just might, make a decent job of it.

This certainly applies in the case of a few spot repairs to bring a car body back to its more or less original appearance. But if we’re talking about a full car respray, then you’ve rally dived in at the deep end.

So, having established that DIY car painting AND getting it right is difficult and getting it wrong is very easy, why would you still tackle it?

Painting a car requires a huge skillset that takes years or even decades to perfect. (Image: Brett Sulivan)

Mainly because you’ll save potentially thousands of dollars as well as learning a new skill.

On the flip-side, making a mess of it means you’ll then have to resort to a professional paint shop which will charge for undoing all your bad work before they start on the actual repainting job.

So, with all that in mind, let’s look at the process in steps as we present our guide on how to spray paint a car step-by-step. (Oh, and let’s leave panel beating to another article, because getting the car’s body straight enough to paint is a whole other can of worms.)

Painting a car is so much more than simply choosing a colour.

1.     Decide on your degree of difficulty and load up on supplies

Are you going to paint the whole car, or just a panel or two? Having made that decision, you can then move on to buying your supplies which will include masking tape and paper, sand-paper, primer, undercoat, and colour coat.

You’ll also need a compressor to power the spray-gun, thinners for clean-up and diluting the paint to the correct consistency and the relevant safety gear.

Don’t forget the little things like clean-up rags and paper filters to prepare the paint for the gun. The pros reckon you’ll need four litres of undercoat and about the same number of litres of colour to paint the average medium-sized car.

Throw in a few litres of thinners and you’re already looking at hundreds of dollars just in paint, so make sure your commitment matches your outlay.

Sticking with safety for a moment, this advice piece is restricted to single stage old-school acrylic and enamel paints. Modern two-pack paints are just too dangerous to use at home and require a ventilated spray booth as well as forced-air breathing gear.

There are simply too many OH&S dangers involved for us to recommend it to even the handiest DIYer.

The one potential exception to this would be if you can hire a professional spray booth and breathing gear. Even then, you need to know the safety drills and be aware of how to make the most of the hardware.

2.     Prepare the surface

Even if you’re just going to paint a small section of the car, the surface needs to be prepared to prevent the new paint simply flaking and peeling off later.

In extreme cases this will involve removing all the old paint via either a chemical paint-stripper, sand or soda blasting or just hours of hard work with abrasive paper.

Even if the old paint is in great condition and you’ll only be patching a small section of it, you still need to scuff, or key, the area around the repair so the paint layers can overlap a little. A common Scotch-Brite pad is a popular way to do this.

3.     Cleanliness is…

Before you can even think about spraying on any new coat of sealer or undercoat, you need to make sure the freshly keyed surface is spotlessly, fanatically clean.

Use compressed air to blow away any debris and then use Prepsol (a specific solvent) to wipe away any grease, residue or even oil from your hands.

4.     Into the booth

Now (after masking up required areas) you can start to apply the new paint and in most cases, you’ll be starting with an undercoat/sealer product that provides a good surface for the new colour coats to go on to.

The best advice seems to be to allow the undercoat/sealer at least 90 minutes in the spray booth to harden and cure before trying to apply anything over the top of it.

5.     Rub it back

Just when you thought you were done with the sanding, the cured undercoat needs to be rubbed back to eliminate any tiny flaws and to keep the surface smooth.

Any imperfections in the undercoat will be covered but not hidden by the new paint. Instead, the flaw will be faithfully reproduced with every new coat of paint and will remain visible no matter how hard you try to bury it under new paint.

6.     More cleaning

Having smoothed the surface of the undercoat, you’ve almost certainly introduced a new layer of micro-filth to the surface. So it’s out with the Prepsol again for another cleaning process.

7.     Colour it in

Now, provided the undercoated surface is spot on, you can apply the colour coats. Let each one flash off (partly dry) before applying the next.

How long between coats? The paint manufacturer will have a view on this, but ambient temperature and humidity also play a part.

Most painters reckon at least three or four (or more) coats of colour is required to do the job properly.

It’s also now, if you’re using two-pack clear-over-base that you can apply the recommended number of coats of clear.

8.     Buff and enjoy

The final process is to cut and polish the newly painted surface. This is done with wet and dry sandpaper and is designed to flatten the paint’s surface, removing all orange-peel and imperfections before polishing the top coat and recreating the shine.

How much does it cost?

Although the above is a very much a broad-brush (excuse the pun) look at the painting process, one thing doesn’t change. It will cost.

Bank on at least $1000 and probably nearer to $2000 for the paint by the time you’ve bought the consumables. And if you’re wondering how much paint do I need, the answer will vary from brand to brand, but figure on at least four litres of undercoat, and the same again in colour-coat and clear-coat.

And that doesn’t include the painting hardware or the booth hire. Or the re-dos when you mess it up.

The final process is to cut and polish the newly painted surface.

Keep in mind, too, that the really high-end brands of paint are a lot more expensive than the cheaper ones and that even some pigments (colours) cost more to produce.

Thinking pearl or candy-metallic finishes? Then add another zero to the cost and another huge degree of difficulty to the task.

By far the best bet is to either do a TAFE course on automotive painting or sit down with an experienced painter and listen to what they have to say.

If nothing else, though, at the end of this process, you’ll definitely understand why having a car repainted professionally is such an expensive business.

Again we have to remind you that this is a potentially dangerous undertaking and not one that a few paragraphs on a website can ever prepare you for.

Ask 10 different car painters 'How to paint a car' and you’ll probably get 10 answers that differ in their details.

The questions of panel repairs, how to prep and repair a surface aren’t going anywhere and you’ll need to address them, too.

And what about the complexities of modern metallic colours and how to match them across different panels?

Oh, and if you’re thinking about changing the colour of the car, be prepared for a whole lot more work as you’re now looking at repainting the door jambs, engine bay and underside of the boot and bonnet to get anywhere near a factory look.

In fact, the whole topic of automotive refinishing throws up more questions than answers, and only experience can really answer them. Even then, ask 10 different car painters 'How to paint a car' and you’ll probably get 10 answers that differ in their details.

How to spray paint a car might sound like a simple question, but it’s far from a simple answer. And for the majority of people out there, if we’ve scared you off the idea, we’ve probably done you a favour.