Clay bars are really great tools for removing contaminants that are bound to your car, like tar, bugs, iron fallout, tree sap and water spots. But can they damage the paint?
In this article, I’ll go through what a clay bar actually does, why it has the potential to cause scratches and swirls, and how to use one safely. So let’s get started.
The Quick Answer
Clay bars are abrasive so have the potential to damage paint by causing clear coat scratches, marring and swirls. You can minimise the risk by using a soft clay, plenty of lubrication and keep inspecting the clay for contaminants that may cause scratches. This also applies to clay mitts and blocks.
What is a Clay Bar?
First, let’s be clear about what a clay bar actually is.
Clay bars can be either natural or synthetic, but the vast majority of clay on the market these days is synthetic. It comes in a large chunk and you can cut it down to size, then flatten it in your hand.
Then you glide it over lubricated paintwork to remove bound contaminants. This process is known as physical decontamination.
It’s an essential step before paint correction, and applying ceramic coatings and sealants to make sure the paintwork is squeaky clean.
But how does it actually remove these contaminants? There are two ways it can do this.
- It pulls them out of the paintwork
- It “shaves” them down until they disappear
It really depends on how stubborn the contaminants are bound to the car. If they are pretty loose, then the clay often just pulls them straight off without any trouble.
But if they are firmly bound to the paint, then they often are effectively shaved down until there’s nothing left on the surface.
Clay is able to do this because it is abrasive.
Clay Can Cause Scratches
So it probably won’t come as a surprise, that clay has the potential to cause scratches, now you know that it is an abrasive cleaning tool.
Your car’s clear coat is incredibly delicate, and any type of friction is likely to cause marring, scratches or swirls. This is why it’s vital to microfiber on the paintwork to dry it, instead of bath towels, and to never use a sponge.
Clay doesn’t cause scratches every single time though. It really depends on how you use it. Here are a few tips to make sure you reduce the risk of causing clear coat scratches using a clay bar.
Use a Lubricant
The most important thing to remember when using clay, is to always keep the paint and the clay lubricated.
If you’re using a clay bar and letting it stick and drag along the clear coat, then it’s inevitable that you’ll cause swirls and marring.
So what can you use as a lubricant? Here are your two options.
- A clay lubricant spray
- Car shampoo and water
Personally I use car shampoo and water. I find that it actually provides better lubrication, and is far more cost effective.
Every time I clay a panel, I’ll wet it thouroughly, then cover the surface in car shampoo (without wax), using a clean microfiber wash mitt, and then I’ll dip the clay bar in the wash bucket.
Always use clean buckets and mitts when claying, never use the same one you used to wash the car beforehand.
Keep Checking the Clay
It’s also super important to keep inspecting the clay as you’re going along. One of the easiest ways to scratch your car using clay, isn’t due to the clay itself, but the contaminants it’s picking up.
When the clay pulls these contaminants off the paintwork, they become stuck to the clay and cannot be rinsed off. If you glide contaminated clay across the paint, then you’ll definitely cause scratches and swirls.
So keep checking your clay bar every few swipes. If you see any contaminants, fold the clay to reveal and fresh side and continue.
Never Drop the Clay on the Floor
It’s also really important to never drop the clay on the floor. If this happens, then throw the clay away and use a new piece.
Clay picks up dirt and grit so easily and clings onto it. If you use a dirty piece of clay on your car’s paint, then you’ll definitely cause plenty of marring, swirls and scratches in the process.
One of the biggest mistakes car owners make when using clay, is being too heavy handed.
Clay is capable of removing contamination, without being pressed into the paintwork. So use the lightest pressure possible. You want the clay to simply glide across the surface.
Remember, clay is abrasive, so if you press to hard and rub it into the clear coat, then you’ll guaranteed to cause marring and scratches.
If you’re having trouble with some stubborn contamination, then instead of pressing the clay harder, move it faster. This will remove the contamination without harming the clear coat nearly as much.
Use Straight Line Motions
Another pretty important tip, is to use straight line motions when claying.
Not only does it help you to keep a track of where you’ve clayed, but it also makes any swirls and scratches that may have inflicted a lot less obvious.
If the scratches are circular, then they’ll hit the light all the time, and be much more noticeable. Straight line scratches tend to be a lot harder to see.
Clay the Area Once
A lot of people clay the same area loads of times to make sure that they’ve removed all the contamination. But this causes way more harm than good.
You should only ever clay the area once, before moving on. Going over the same area dramatically increases the risks of scratches.
If the surface feels smooth when you’ve gone over it, then the contamination is removed and you’re fine to move on to another section.
Use the Right Type of Clay
There are many different types, or “grades” of clay. For example, you can get some varieties of clay that are hard, soft or medium.
You should always use the softest clay possible for the job. Using a “harder” clay, really does increase the risk of scratches. This is because harder grades of clay are more aggressive, and more abrasive.
Instead, use a softer grade to prevent scratches and swirls from occurring.
Only Clay When Necessary
So this is the final tip for using clay and minimising the risk of swirl marks and scratches.
It simply isn’t necessary to use clay as part of a routine. Don’t think that you have to clay your car every 3, 6, 12 months. However long you’ve read online or been told by a friend.
You should only ever clay your car when it has contamination on the surface. Sometimes, this isn’t very often, particularly if the car is stored in a garage.
The best way to minimise the risk of scratches, is to simply use clay less often. Take a look at this article I’ve written that will take you through a neat trick to tell when your car needs claying.
Now we’ve been through the top tips for using clay safely to reduce the risk of scratching the clear coat, let’s go through some of the other most frequently asked questions.
Does you have to polish after claying?
You do not always have to polish a car after claying. If you used the clay bar safely, then there shouldn’t be any scratches or swirls in the paintwork. You can check if the car needs polishing by inspecting it in direct sunlight, or using a torch to see if there are any scratches and swirls that need correcting.
which clay bar is best?
I’ve not tried every clay bar under the sun, but I use and fully recommend Bilt Hamber Soft Clay. The clay can be used with only water as a lubricant, so it’s one of the safest clays to use to avoid scratches. I still use car shampoo though, just to be on the safe side. I like to use the soft clay because I find that it’s abrasive enough to remove contamination without risking scratching.
will clay mitts and cloths scratch the paint?
Clay mitts and cloths have as much chance as scratching the clear coat as clay bars do. I personally don’t use clay mitts and cloths because I prefer to just throw the contaminated clay away after using it. I don’t like how mitts and cloths are more expensive and encourage you to re-use them. This can increase the risk of scratches if you use contaminated tools.
Thanks for reading! I hope you’ve found this article helpful. Check out the rest of the website to learn more about car washing and detailing.