contents
- How does car painting work?
- Paintwork damage: Possible consequences
- You should not repair this paintwork damage yourself
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Detect repairable scratches in the car paint
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Touch up scratches and minor paintwork damage yourself
- The right means for all kinds of scratches, streaks and swirls
- Paints unsuitable for repairs on cars and motorcycles
- Repair car paintwork yourself: you should pay attention to this
- Conclusion: Repair of paint damage on vehicles
How does car painting work?
In the 1970s, metallic paintwork was only available at extra cost, but today it is standard with every well-known manufacturer. Modern, industrial, robotic car paintwork consists of several layers.
The paint layers of a car paintwork
Car manufacturers all follow a similar procedure.
- The sheet metal of the body is first coated with a phosphate. This prevents rust and ensures better adhesion of the subsequent coats of paint.
- The first actual layer of paint is the primer, which also serves as a primer and is intended to prevent rust. These first two layers and the quality of the sheet metal used are the reason why the major car brands can now give a guarantee of 10 years and more against rusting through.
- A filling varnish is applied to the primer, which ensures an absolutely even surface.
- Only then is the metallic paint sprayed on, which is protected by another layer of clear paint. However, there are deviations here, for example when a metallic effect finish is intended to make a car appear particularly shiny. Touching up such paintwork is generally rather difficult for the layperson.
Paintwork damage: Possible consequences
There is no need to rush if the damage to the paintwork of the vehicle is only a matter of light streaks that have only affected the clear coat. These are more of an aesthetic fix.
However, as soon as the paint layer, i.e. the metallic paintwork, is affected, you should react quickly: there is a risk that moisture will penetrate through the finest pores to the bodywork and corrosion will occur. The catch is that you can’t see the beginning pitting. Sometimes it happens that such damaged areas are repaired with great care and blisters appear weeks later. The paint is peeling off and under it a very advanced corrosion is visible. If this is the case, the damage to the paintwork was repaired too late and rust had already formed in the lowest layers.
You should not repair this paintwork damage yourself
When repairing paintwork damage, it always depends on how deep the damage is and how large the affected area is. Two basic rules must be observed: If the scratches are so deep that the filling layer is completely damaged or even the primer is affected, a specialist should repair the damage to the paintwork. This is especially true when the bare metal is already visible. This is easy to recognize: a fine but clearly visible layer of rust usually forms within hours.
Larger areasespecially in exposed places such as the doors, the bonnet, on the trunk or on the roof can only be repaired with a lot of skill. Most of the time, the repair area is so obvious after the work is completed that it is annoying and almost forces you to visit the painter.
You should also refrain from DIY painting on classic cars and vehicles that have been outdoors for a long period of time. Here the car paint is almost always so faded by the UV radiation in the sunlight that even the original paint differs significantly from the actual color. In that case, you’d better let a professional do it.
Detect repairable scratches in the car paint
Not everything that looks like a scratch is actually one. If two vehicles touch or you hit a boundary post, for example when parking, it often happens that there is no real damage to the paintwork. Instead, there is paint transfer from one car to another, or pillar to body, which appears to be similar to a scratch. Such paint transfer can often even be removed with a damp microfiber cloth. If more paint was transferred, a fine polish removes the unwanted marks.
However, if there is actually a scratch, you must check whether you can repair this damage to the paintwork yourself. To determine this, run your fingernail very carefully over the area with the scratch: If the nail slides over the scratch without much resistance, you can repair the paint damage DIY. If your fingernail gets stuck in the scratch or gets caught in it, it is usually too deep to repair it without professional help.
Touch up scratches and minor paintwork damage yourself
Before you attempt to repair the scratch or stone chip, remember that every car is different. Minor scratches in softer clear coats are quicker and easier to repair. Deep scratches in hard clear coats require a little more time and effort. Also, every scratch is unique. Depending on the size and depth of the scratch, you may be able to solve the problem in two minutes or it may take 20 minutes. Just start paint repair with patience. If things aren’t progressing as quickly as expected, keep at it, and you’ll eventually get the results you want.
The right means for all kinds of scratches, streaks and swirls
It is important that you select the right tools and means to make the car paint repair a success. Hard wax is often wrongly applied in the belief that this can also remove scratches. This work step is counterproductive, because the hard wax then not only protects the paint, but also the scratches.
Microfibre cloths, polishing cotton, cotton rags
In principle, it doesn’t matter whether you work on a scratch with a microfiber cloth, polishing cotton or a cotton cloth. The work results are almost identical. However, polishing cotton produces an unnecessarily large amount of avoidable waste. Cotton cloths are usually no longer suitable for further use after the repair has been completed and therefore usually also end up in the garbage can. Microfiber towels are easy to wash and reuse. In addition, they have the advantage of a slightly rough structure, which is ideal for manual polishing on a car paint.
polishing machine
Polishing machines are a real help, especially for larger areas or if you want to bring the entire car to a high gloss. However, there are differences here: The so-called rotary polishers only offer the function of a rotating polishing wheel. As a result, experience is required to work successfully with these devices. A little carelessness is enough and deep streaks or swirls have formed in the paint that are difficult to remove.
The so-called eccentric polishing machines are easier to operate and handle. Here, the polishing pad not only rotates, but also performs eccentric movements, so that an even polish is automatically created. Both device variants can be equipped with different polishing attachments. For polishing, i.e. for removing scratches, polishing pads made of foam, those with a microfiber cover or those with a sheep’s wool cover are particularly suitable.
polish and grinding paste
Pure polishes are suitable for polishing up scratches, streaks, swirls and holograms. These contain tiny abrasives that dissolve the paint in the decimal micrometer range and thus create a new, closed layer. Some modern products also contain nanoparticles that absorb the color of the paint and fill in the scratches.
A grinding paste should only be considered for coarse scratches. Their grinding particles are relatively coarse and therefore remove large amounts of paint. If you polish too much, the primer will quickly come to light and the surface will then have to be completely painted.
Touch-up pencils and similar products
A crater can be painted over with a touch-up stick. After the paint has completely dried and hardened, which can take up to 10 days depending on the product, the repaired area is sanded down to give a uniform paint finish.
Multifunctional products and car waxes
Some manufacturers offer polish and wax in a combination product, often with nanoparticles and other agents as additional ingredients. These products are good as long as the car paint is undamaged. However, these agents are not very suitable for repairing damage to the paintwork, because a step-by-step approach is required for a good result.
Paints unsuitable for repairs on cars and motorcycles
Special paintwork is generally not recommended, as it can happen that the damaged area is clearly visible afterwards. These include, for example:
- Leaf metal finishes
- pearl effect paints
- Candy liveries
- matt varnishes
- multicolored paintwork
DIY repairs are not recommended for all Art finishes, especially for airbrushing.
Repair car paintwork yourself: you should pay attention to this
If there are many deeper scratches, scratch marks and swirl marks all over the car, you should first subject the entire vehicle to an intensive polish. You can then easily determine which scratches have already disappeared, which you can rework yourself and which paint damage requires professional help.
When polishing, it is important that you go over the scratches in a circular motion. Don’t apply too much pressure to the paint, as this will remove too much of the paint layer and reveal the primer. If it’s a long scratch, continue using circular motions down the length of the scratch. Wipe off excess polish with a clean cloth and keep checking on your work progress. If the scratch is gone and the repaired area blends well with the surrounding paint, you’re done! If the scratches are still visible, simply repeat the steps until the damage is gone.
Add touch up paint
On the rare occasion that multiple passes have not completely removed the scratch, you can always use color-matched touch-up paints to fill in the imperfections. This is very time consuming because you have to wait for the added color to set. But the result is rewarding, because a new layer of paint is created that makes your car look like new.
Paintwork repair with the polishing machine
If you have a polishing machine, you can remove the scratches yourself much easier. Spread a fine polish onto the buffing pad, set the buffing machine RPM to low, and work the polish over the scratch. As the work progresses, the speed of the machine is gradually increased – but the contact pressure is never increased. In this way, even deeper scratches, extensive streaks, swirls and holograms usually disappear in a short time.
Conclusion: Repair of paint damage on vehicles
Patience, the right products, optimal tools and some skill are required if you want to repair the paintwork damage on your vehicle yourself. Repairing scratches or stone chips maintains the value of your car, protects it from rust and you get a higher price if you want to sell your vehicle later. However, if the scratches are too deep, you should definitely seek professional help: otherwise you risk corrosion. This can impair driving safety.