Cars get dirty when being driven and many car owners want to clean them themselves and get them looking great. To do so, you need to understand a little about what a dirty car really is and that preparation is typically more important than slapping a bit of "polish" on a quickly washed car.
It's important to know that the vast majority of modern cars have a base paint colour and then a layer of clearcoat over this. You really want to avoid doing anything that gets through the clearcoat, and it's getting the clearcoat flat, blemish free and sparking that will make your car look great. This guide talks through some basic steps. We've also listed the key products you may need on our Essentials page.
A dirty car will have mud and grime on the car as you'd expect, but it will also typically have a few other issues. Through use and especially washing, small fine scratches build up on the paint surface. These are sometimes called swirl marks or spiders webs and you see them when the sun is at a certain angle.
You can also get deeper scratches, maybe from a coat that's been accidently dragged across the paint or maybe a stone ship. These can scratch the clearcoat deeper than a swirl mark.
Washing your car gets rid of the obvious dirt as the diagram shows, but if you've ever wondered why it can still not shine or why it can feel rough to the touch, it's because you've only remove one of the problems. In addition to mud and grime, you may also have tree sap, tar spots, even fine iron particles that stick to the paint. We'll cover how to deal with these issues and fine scratches in a bit.
The first thing to do is to clean the dirt off a car without causing more damage like scratches. As an extreme example, you could use wire wool to help remove dirt, but it's obvious that this would cause other damage to the paint, and the same is true with a dirty sponge that has picked up grit and dirt. To clean the car, you want to try to touch the paint as little as possible when its dirty, and when you do touch the paint make sure what you're using, such as washing mitts or microfibre cloths, are as clean as possible.
One of the best ways to get rid of quite a lot of dirt is to use snow foam on the car. The device attaches to your jet wash and leaves the car with a blanket of thick foam that lifts the dirt and helps remove the worst without you physically touching the car. Spray it on, leave it to dwell for a few minutes and then rinse it off before it's had time to dry. Once this is done, you can then wash the car. It's best to have a second bucket of water handy to rinse your sponge or washing mit before loading it again with clean soapy water. You don't want the dirt that you've just removed to be put into the clean water, picked up by the sponge and then to cause damage to the next part of the car you're about to wash.
It's also advisable to clean the wheels first using its own sponge, and then to use fresh water before cleaning the car rather than wait until the paint is washed and use what's left of the soapy water to clean the wheels.
You can stop at this point, and if doing so, you can pat the car dry with a microfibre cloth as tap water usually leave a trace on the car when it dries. To help not leave these water spots, you can get a water filter than purifies the water and can be used on the final rinse.
To get rid of tar spots and other contaminates on the paint that are either unsightly or leaves the paint feeling rough, a different approach is required. You can buy chemicals that you spray on which help dissolve tar spots and even small particles or iron that can get attached to the paint. Even when this has been done, the paint usually feels slightly rough to the touch after a number of months. To remove this, you need to clay-bar the car. A piece of refined clay, used with some lubricant (we like to use concentrated car wash), is rubbed over the paint. It sounds grim, but you will quickly see, even on what you thought was a relatively clean car, the clay getting dirty and the paint becoming increasingly smooth. After claying the car, it's worth giving the car another wash to remove any residue from the lubricant you used, and a rinse with either filtered water or dried off with a microfibre towel.
If you decide to clay bar your car, you must at least apply a wax to the car afterwards as you will have removed all the protection.
We should now have a car that looks clean except those fine scratches that can catch the eye in some light, and some deeper scratches. You can approach the next step in one of two ways, the first is to polish using a product containing fillers, something like Autoglym Super Resin Polish, sometimes called a glaze. The idea here is that the polish actually contains something that goes into the fine scratches and helps mask them. It's non-destructive to the paint, doesn't take long and can give quite pleasing results to the owner. However, it doesn't last that long before it needs to be done again, maybe a couple of months. This will mask most of the light scratches to some degree and soften deeper scratches.
If you consulted a professional car detailer, especially if you were looking to put a ceramic coating or protective film over the paint, the use of a polish with fillers is not suitable. They would use a machine polisher to effectively cut away the top surface of the clearcoat until they reach the bottom of the light scratches and hence making them disappear. If the clearcoat is thick enough, they may decide to go a little deeper in places to remove all the scratches. This lasts much longer as it's a permanent fix and the damage only come back over time as the scratches are made again on the paint.
Depending on which of the above steps you do, you should have a lovely clean and glistening car ready for some form of protection.
The choices you have are:
Wax has been used for many years and they vary in quality, how easy to apply, and how long they last. Good waxes include Autogylm high definition wax and ones by Collinite, although these can be hard to use. You can also buy spray on waxes that are easy to apply look ok for a while, but tend not to last as long.
Sealants are usually synthetic and can be used instead of or on top of a wax. Autoglym Extra Gloss Protection is one such product and can be used when the car is wet from washing. The product helps the car dry without spot and can be easily buffed off when dry to leave a shine. It's a useful product in winter when the cold weather makes car drying difficult and you don't want to spend too long outside.
Nano or ceramic technology are products that work more at the atomic level and create a strong water repellent covering. These coating, like gtechniq exo, can last a year or more and can be boosted by a wax or sealant during the year. These coating can often only be removed through machine polishing and require a high degree of preparation before application so are typically best left to the professionals.
You will see on the market products that claim to be all things to all people, the wash and wax all in one type products. They're ok for a quick top up, but in reality, they only remove the dirt and then place a layer of protection over the other forms of damage to the paint.