Cleaning a car – practice

Because spring is coming again. Because then classics can shine again. Cleaning a car, what kind of polishes are there. Are all polishes equally good? Paint cleaners, scratch fillers, polishing pastes, sealing products, gloss, carnauba wax, showroom finish. What should we do with it? Many classic enthusiasts are in despair before the shelves with cleaning and care products. Here comes a signpost through the produce jungle.

Is everything really good?

Frankly, I had imagined more when I saw Christian Petzoldt's warehouse. For example, more clarity. At least an indication which brand the professional uses. Totally wrong. Although Christian even runs his own brand, his warehouse seems like a small Calais for various brands of polishing pastes, cleaners, waxes and other car care products. So there is a lot more to consider when choosing a product for cleaning your car.

The craftsman smiles broadly: “There is no such thing as a brand that is so good across the board that it puts everyone else in the shadows, but there are companies that are at the highest level with their entire line.” But almost every manufacturer has a top-rated car polishing program that stands head and shoulders above the rest. It took me almost twenty years to find my ideal means. And every year there are improved recipes and completely new products. It is impossible for a hobbyist to find his course in that range. But life is easier for classic car enthusiasts. The products for their hobby have crystallized for years.

But still: the creativity of the marketing strategists and the commercial copywriters make the orientation within the lacquer care segment challenging to say the least. One offers polishing cream for car polishing. The other a lacquer sealer. The next one sells showroom shine. But what's all that stuff for?

Abrasive Ingredients

Christian explains: “In principle there are polishes and preservatives that should preserve and protect the shine after a polishing or buffing session. Then there is of course a multitude of cleaning and aids, but the first two main groups are the basis of and for everything. The polishing pastes and cleaners differ in the amount, coarseness and hardness of their abrasive components. The larger and harder the abrasive components are, the more lacquer they remove. And of course a more aggressive agent is needed to polish a slightly rusted chrome layer than to polish a slightly weathered layer of lacquer. Therefore, chrome polishes are not suitable for use on paintwork when polishing the car.”

“Second place in terms of abrasive grain size are scratch removers and polishing pastes. Because they have to deal with deep paint damage, they have to take quite a lot of material. Professionals use exceptionally fine polishing paper with a grain size of 2000-2500 in such cases. This also removes a considerable amount of the top layer of paint. That is why such agents should never be used on very old paintwork. They have become quite thin due to years of polishing and before you know it you are on the base coat. Oh yeah; don't expect too much from the miracle cures offered online.”

Paint cleaning agents

In the next shelf we find the paint cleaners, the name of which is somewhat confusing, because they do not remove dirt. But these 'cleaners' are in between the grinding and polishing pastes in terms of character. And how hard or soft these types of agents deal with the paint varies per manufacturer. The top brands often give their users the choice between three, four or even five gradations in cleaning and polishing agents. And with that, every paint can be customised. And that makes the chance of wrong choices when cleaning a car as a hobby considerable.

What kind of polish

Christian Petzoldt: “Actually, it is always the case that as little old paint as possible should be removed when polishing the car. Then the paint lasts longer before the primer coat has been reached and there is no need to 're-polish' to get the paint back to a high gloss. That saves time, and also paint.” There's a simple trick to seeing which polish is best. “Wash the car and put it in the sun after drying so that the fine scratches become visible. Those are the traces of earlier turns of car cleaning and car wash visits. Then choose a product and use it to polish in a place that is as inconspicuous as possible, such as on the passenger side near the sill. If circular polishing marks become visible in the paint, the so-called holograms, then you should no longer polish in circles, but in straight lines. Otherwise, the abrasive components will collect in the scratches and become even deeper.”

“The polish with which the holograms are just diminishing enough to take the holograms off again is the good thing.” If it concerns products from the same manufacturer, an even higher efficacy can be made 'tailor-made' by mixing yourself. There are also providers that save customers the trouble of choosing. Fortunately, this does not mean that these resources have a very limited usability. Christian explains: “Polishes that fix everything in one go were originally developed for the automotive industry. Time is money there and paint imperfections must disappear quickly and without a trace. The abrasive grains of these pastes are constructed in such a way that they are coarse enough at the start of the car polishing to remove scratches. During brushing, they disintegrate until they are finally fine enough to make even the finest brush marks disappear. A genius concept! To really solve everything at once, a wax is often added to these products. The wax then fills in the last hairline scratches and provides a beautiful shine.”

Combi products or not

But for ultimate quality, the patchwork remains because the wax reduces the shine rather than increases it. Christian proves this with a device that measures the reflection value of the paint. The gloss level of a freshly painted car is indicated at 88%. After a final session of car polishing, that could become 91%.

Unfortunately, you cannot expose that result to the outside world with impunity. The wax layer serves as protection against the weather, but this is at the expense of the final sharpness in the gloss. This also means that combi products can never lead to a top result. Not even if they fill the last minimal polishing marks with lacquer. It is easy to see how large the proportion of wax that a veil casts over the brushing result. To do this, the wax must be removed with a cloth soaked in alcohol. If the paint still shines nicely, the smoothness of the paint is OK. If the shine largely disappears, then the wax layer was a combination product, a 'blender'. But for hasty old-timer friends, such a color wash can be a solution.

polishing machine

The perfection in car polishing is therefore only approached by a polish with the finest possible abrasive particles. However, these products remove so little paint that they can in fact only be used after one or more polishings with coarser pastes. So if you want to go for a shiny end result, you should prepare for a day of brushing, including muscle pain. And although most products can also be used with the machine, Christian advises against this. “Polishers are very fast and effective, but they can do damage just as quickly and effectively.”

For hobbyists who still want to tackle larger surfaces with the machine, he recommends eccentric polishers with a cleaning sponge. These devices are less likely to create holograms and are easier for hobbyists to handle.

He has another tip for us: “Just as you can make intermediate steps by mixing products, you can also play with the cloths and sponges. A harder sponge supports the abrasive effect of the pastes. And the most beautiful shine can only be achieved with the softest polishing sponges.” The old faithful cleaning cotton is a thing of the past for the pros. As with their polishers, they use sponges to apply the polishes. There are also options for cleaning things up. The first is the use of towel-sized cotton cloths. But microfibre cloths are even better.

But beware: the special microfibres for polishing paint are softer than the microfibres of the cloths that are for sale in every supermarket. “You can use it if, for example, you want to remove old wax layers from the paint with dishwasher detergent. Then the sharp microfibres come in handy.” To polish, the soft quality is needed, which is recognizable because the edges are not hemmed. Because the stitching of those seams also causes scratches in the paint. However, to be on the safe side, the soft cloths should always be folded in such a way that their edges cannot touch the paint.

wax layer

Professionals apply the preservative wax layer with a sponge. Here too the following applies: 'less does more'. With just a little wax on the sponge, the wax is massaged into the paint with a little pressure and circular movements. After that, the pressure must be reduced to get the excess wax back into the sponge. Even before the laundry has dried, it must be polished with a microfibre cloth. Rubbing it out should be easy. If it is stiff, you have waited too long and the wax has dried out.

Speaking of hard wax: Carnauba is considered to be the hardest natural waxes and is now found in various doses in the wax sealers of many manufacturers. As a raw material it costs about 13 euros per pound and after that it still has to be extensively processed. After all that extra work from lab technicians and marketers, the end product in glossy packaging can have a price of 1.000 euros per kilo. No matter how expensive a wash may be, Christian is sure of it: “People polish too often and wax too little. A hard wax coat survives five to seven hand washings before needing to be reapplied. If that happens, cleaning is unnecessary. There is no end to sitting in the wash. But whoever lets the matter get to the point where it needs to be cleaned again, mistreats his paint.”

With old-timers that don't get out much and often still sleep indoors under a car cover, it can take a very long time before a new layer of wax is needed. But if the matter is kept up to date, then that is a guarantee for a long and happy life of the coating.