With this counter we check if the car is damaged
Today, without a thickness gauge, buying a used car is like playing Russian roulette. Unfortunately, it is not difficult to find unscrupulous sellers, so such a device can even do more than a professional mechanic's eye. We advise which paint thickness gauge to choose, what parts of the car to measure, how to measure and, finally, how to interpret the results.
The wave of used cars that reached Poland after our country's accession to the European Union has probably exceeded all expectations. However, thanks to this, people who count every penny have the opportunity to buy a car at a really affordable price. Worse, their technical condition and past accident are different. Hence, if we want to spend our money well, it is our responsibility to properly inspect such a used car. Well, unless you unconditionally trust the assurances of the seller. The technical condition will be well assessed by a trusted mechanic, and we can check the accident ourselves. I'm good at using a paint thickness gauge.
Counter types
Sensors, also known as paint thickness testers, allow you to check the thickness of the paint layer on the car body. The offer of this type of device on the market is huge, but it is worth remembering that not all of them will provide a reliable measurement value.
The cheapest testers are dynamometric, or magnetic, sensors. Their shape resembles a felt-tip pen, they end with a magnet that is attached to the body and then pulled out. The movable element of the sensor, which extends, allows you to evaluate the thickness of the varnish. The larger the layer of varnish or putty, the less the moving element will protrude. The measurements made by such a meter are not always accurate (not everyone even has a scale), it allows you to estimate the paintwork as approximately as possible. The simplest such counters can be bought for as little as 20 PLN.
Of course, a more accurate measurement can be obtained using electronic testers, the price of which starts at about PLN 100, although there are meters that are several times more expensive. The main parameter we need to check before buying is the measurement accuracy. Good counters measure to within 1 micrometer (one thousandth of a millimeter), although there are those that are accurate to 10 micrometers.
The large price range is also due to the various additional features that these types of devices offer. It is worth thinking about buying a meter with a probe on the cable, thanks to which we will get to many hard-to-reach places. A very useful solution is, for example, the assistant function in the Prodig-Tech GL-8S, which independently evaluates the measured coverage, informing whether the car has had a body and paint repair. Another important feature that a good thickness gauge should have is the ability to select the type of material (steel, galvanized steel, aluminum) of the body (sensors do not work on plastic elements).
If you use this type of equipment professionally, then you should bet on even more advanced counters, the price of which will already exceed the bar of five hundred zlotys. In this price range, it is better to choose a movable, spherical head (rather than a flat one), which will allow you to measure numerous irregularities. Some heads also allow fairly accurate measurements, although the body is dirty. However, as a rule, the measurement should be carried out on a clean car body. Available features include, for example, the ability to recognize whether a ferromagnetic sheet is coated with a zinc layer or not. Thanks to this, it will be possible to check whether some body parts were replaced with cheaper non-galvanized parts during the sheet metal repair. An exemplary tester in this price range, the Prodig-Tech GL-PRO-1, priced at PLN 600, has a 1,8-inch color LCD display that shows the current measurement, measurement statistics and all necessary functions.
See all models on the website: www.prodig-tech.pl
How to measure
To reliably assess the condition of the car's paintwork, each painted part of the body should be checked by a tester. Fenders (especially the rear), engine hood, tailgate and doors are particularly susceptible to damage, making body and paint repairs possible. However, we must also check items such as sills, outer pillars, shock absorber seats or boot floor.
When measuring, each element should be inspected at least at several points. In general, the tighter we test, the more accurate the measurement will be. Not only too high and too low readings, but also too large discrepancies in measurements should be of concern (more on this below). It is also worth comparing the symmetrical elements of the body, that is, the left front door with the right or both A-pillars. Here, too, you can check if the discrepancies in the readings are too large.
How to interpret the results
The problem with taking measurements is that we don't know the factory paint thickness. Therefore, it is worth starting the test by checking the thickness of the varnish on the roof, as this element is rarely revarnished and can be used to determine the reference value. It should also be remembered that the thickness of the paint on horizontal surfaces (roof, hood) is usually slightly greater than on vertical surfaces (doors, fenders). On the other hand, invisible elements are painted with a thinner layer of paint, which can be explained by the cost of painting.
If during testing these values fluctuate between 80-160 micrometers, we can assume that we are dealing with a once painted element covered with factory varnish. If the measured level is 200-250 micrometers, then there is a risk that the element has been repainted, although ... we still can't be sure. Perhaps the manufacturer simply used more paint for some reason in the tested model. In such a situation, it is worth comparing the thickness of the varnish in other places. If the differences reach 30-40%, the signal lamp should light up that something is wrong. In extreme cases, when the device shows a value of up to 1000 micrometers, this means that putty has been applied under the varnish layer. And that's a lot.
Too low tester readings should also be of concern. Except in natural places where the manufacturer applies less varnish (for example, the inner parts of the rods). If the result is less than 80 micrometers, this may mean that the varnish has been polished and its top layer has worn off (the so-called clear varnish). This is dangerous as the following small scratches or abrasions can damage the paintwork itself by re-polishing.
Spending several hundred PLN on a quality paint thickness gauge is a very smart investment for people who are thinking about buying a used car. This can save us from unexpected expenses, not to mention the threat to our security. What a priceless sight when, when inspecting a used car, we take out a pressure gauge and suddenly the sellers remember the various repairs that were made on this, according to advertising, accident-free copy.
