Many car owners wash their vehicles at home, but unfortunately a lot of them are using the wrong chemicals and damaging their car’s paintwork. One of the most common car washing mistakes is using dish soap (e.g. Dawn or Fairy Liquid) to wash the paintwork. But why is it such a bad idea?
Dish soap or washing up liquid should not be used to wash a car. This is because the chemicals will abrade and damage the paintwork and promote rusting. Dish soap can also clog up or remove waxes and sealants on the car. Instead using dish soap, dedicated car shampoo should be used instead.
Issues with Dish Soap
There are three key reasons why dish soap should not be used to wash a car:
- Promotes oxidation and rust formation
- Degrades and clogs paint protection
- Is abrasive and offers limited lubrication
Promotes Oxidation
One of the biggest issues with using washing up liquid to wash a car is that it promotes oxidation. This is because dish soap contains corrosive salts and other chemicals which are very harmful to a car’s paintwork.
Oxidation leads to dull and flat looking paintwork over time as it causes the clear coat layer of paint (which sits on top of the color coat and makes it look shiny) to degrade. It can accelerate rust formation where the bare metal has been exposed by rock chips, and in hard to reach areas on the vehicle.
Degrades and Clog Waxes and Sealants
Another issue with using dish soap such as Dawn or Fairy Liquid to clean a car is that it likely to degrade and even completely remove any existing waxes or sealants on the car. The detergents in dish soap are just too aggressive and not formulated to preserve that layer of protection.
It’s important to keep the car protected with a wax or sealant to shield it from the elements and keep it in the best possible condition.
Dish soap can also actually clog up the layer of protection on the paintwork (if it doesn’t strip it off) which will cause it to perform poorly. This clogging effect also means that dish soap shouldn’t be used even if you’re intending to remove the wax from your car.
If you want to strip any existing wax, check out this article I’ve written on 5 ways to remove waxes and sealants from a car for much better alternatives.
Offers Poor Levels of Lubrication
When washing a car, it’s important to ensure that your wash mitt is properly lubricated with car shampoo so that it slides nice and easily over the panel removing the grime as it goes. If the wash mitt isn’t lubricated properly, then it will increase the likelihood of causing very fine scratches in the paintwork.
Dish soap just doesn’t offer the same level of lubrication as a high-quality dedicated car shampoo does, and hence won’t keep the finish as scratch-free and shiny. This is because dish soap is considered an “abrasive soap”, which is what makes so good at cleaning dishes, but bad for cleaning cars.
Use Car Shampoo Instead
Thankfully, you don’t have to rely on household chemicals to wash your car, and there are literally thousands of car cleaning and detailing brands on the market with far better alternatives which are also very easily accessible.
A car shampoo is far better for washing a car compared to dish soap for the following reasons:
- It does not contain aggressive chemicals which will harm the car’s exterior surfaces
- It offers plenty of lubrication to minimise the risk of scratches
- It won’t clog up or degrade any waxes and sealants
- It rinses away easily to leave a residue-free finish
If you’re in the UK, check out the Garage Therapy /ONE: Car Shampoo. This is my favourite shampoo as it is super high quality but also very cost-effective too.
If you’re based in the US, check out the Turtle Wax Hybrid Solutions Pro Pure Wash. This is another great shampoo which I use quite frequently on my own vehicle.
Do not use any household cleaners to wash your car. This includes laundry detergent and bleach. These chemicals are very harmful to a vehicle in the same way dish soap is. Whether you’re cleaning the interior or exterior, always stick with dedicated car cleaning chemicals designed for the specific area you’re working on.
Check out my complete guide to washing your car to learn all the tips and tricks you need, and the best products to make your car look as clean and shiny as possible.