Car washing by Koch-Chemie

Car washing with Koch-Chemie starts before the wash mitt

A bucket alone won't give you clean paintwork. Koch-Chemie Vorreiniger B "Vb" loosens bonded dirt before you touch the car, while Koch-Chemie Green Star "Gs" handles specific cleaning jobs. Koch-Chemie Mehrzweckreiniger "Mzr" is reserved for suitable interior surfaces and specialist applications. With a conventional wash, rinse the car before starting the contact wash.

A conventional wet wash is a form of car washing that starts with checking the vehicle, chemically loosening dirt and rinsing thoroughly. Next come a contact wash suited to the surface, a clean-water rinse, drying and a final inspection. Each stage should remove dirt from the process, rather than push it across the next panel with more pressure. The main Koch-Chemie collection covers other areas of car care and the rest of the brand's range.

Green Star "Gs", Mehrzweckreiniger "Mzr" and Vorreiniger B "Vb" are selected examples to help you choose for different washing jobs. Each has its role: Vb and Gs belong in clearly defined pre-wash or specialist cleaning processes. Mzr isn't a catch-all addition to your paintwork wash bucket.

This broad category brings together wash, pre-wash, decontamination and car wash equipment products. Treat this guide as a map of the process. The linked product pages explain individual products; the subcollections focus on specific tasks. Always choose by surface, type of dirt, temperature, drainage and the current label. Koch-Chemie Rapid Rinseless Wash "Rrw" offers another route for lightly soiled vehicles: a rinseless wash, with no rinse afterwards, following its own product instructions.

• Particles first: With a conventional wash, rinse off loose particles before a wash mitt or other wash tool touches the paint. For bonded dirt, Koch-Chemie specifies a Vb pre-wash dilution of 1:30 to 1:50, followed by a thorough pressure rinse.
• Match the cleaner to the area: Green Star has different dilution ranges for different jobs: 1:5 to 1:30 for exteriors and engines, 1:10 to 1:20 for interiors and textiles. Choose the range for the surface you've checked, rather than using the same mix everywhere.
• Remove the dirt: Use Mzr at 1:5 to 1:50 on suitable interior surfaces and specialist areas, depending on the dirt. Remove residues with a damp cloth or wet-and-dry vacuum. These surfaces need a different finish to the job from rinsing down bodywork.

Day-to-day from Detailing1: Before drying a conventionally washed car, check the mirrors, number plate surrounds and fuel flap for trapped water. Open accessible flaps, check the gaps and rinse out any remaining residue. If dirty water still runs out, the wash isn't finished, however clean the main panels look.

Five starting checks set the course for a safe wash

Before washing, check five things to choose your approach: surface temperature, direct sunlight, visible existing damage, changes of material and controlled drainage. A hot car, a lifting paint edge or an unfamiliar matt wrap can change the plan straight away. A quick check now saves you trying to work out later where a change came from.

Don't just judge dirt as heavy or light. Loose mineral particles, greasy traffic film, insects, iron contamination, tar and organic residues respond differently. The main wash can reveal problems that need specialist treatment; it doesn't have to solve every one with the same product.

Split the car into working areas: roof and upper glass and paintwork, mid-height sides, front, heavily soiled lower areas and wheels. Interiors, engine bays and workshop floors need separate tools and water routes, even where the products overlap. Give each area its own cloths, wash tools or brushes.

Photograph existing damage. Stone chips, lifting wrap edges, cracked seals, dull repair patches and exposed paint edges can become more obvious during rinsing. This record helps distinguish the starting condition from anything that happens during the wash.

For a conventional wash, plan the water supply and drainage before applying foam. Keep the hose, pressure washer and tools within reach. Don't spread a rinse-off cleaner over an area unless you can rinse it fully straight away. Site procedures and environmental requirements determine where the water goes.

Note any existing protection too. A coating, meaning a protective layer, wax or an unknown treatment can change how water wets the surface. Choose cleaners according to that protection product's care instructions. Weaker beading doesn't automatically mean the product has failed or the paint is damaged. Check the protection separately once the cleaning is done.

Only choose your first test area once all five starting checks are clear. It must be the same material as the area you plan to clean, and you must be able to wet it fully, work on it, rinse it during a wet wash and inspect it dry. A test on glass doesn't confirm compatibility with paint; a test on a tough sill doesn't cover a matt wrap.

Vorreiniger B needs the right dilution and dwell time

Vorreiniger B is alkaline, meaning basic rather than neutral, and helps loosen bonded dirt before the contact stage of a vehicle wash. Koch-Chemie gives a broad dilution range of 1:3 to 1:300 across its applications. That's no invitation to guess. It shows that the application and the car wash system determine the dose.

Koch-Chemie specifies 1:30 to 1:50 for pre-washing and 1:300 for self-service pressure washing. These are different applications. Choose the dilution for your process and follow the corresponding dwell-time instructions. Don't copy a machine wash setting into a manual pre-wash without checking it.

Apply to a cool surface you've checked. Cover only as much as you can rinse completely within the controlled dwell time. Direct sunlight and drying product are signals to stop. In practice, work in sections rather than foaming a whole large vehicle when you can't be sure of rinsing it in time.

Vb is intended to loosen bonded film before contact washing. After the specified dwell time, rinse thoroughly from top to bottom and flush out the gaps. The aim is to carry the loosened dirt away with the rinse water before your wash tool touches the surface.

Take another look at the surface before a second pre-wash cycle. Remaining tar spots or iron fallout don't prove that your Vb mix was too weak. They may need their own specialist treatment. Repeating the wrong chemistry at a stronger dilution or for longer only takes you further down the wrong path.

Label the working bottle and dosing system with the product name, mixing ratio and date. For machine applications, follow the calibration and current process instructions. Don't try to fix an unknown leftover mix by topping it up.

The Koch-Chemie pre-wash cleaners subcollection helps you compare other pre-wash products. Here, Vb illustrates the principle: defined limits, a cool test area, no drying on the surface and complete removal.

Green Star has its place in targeted alkaline cleaning

Green Star is a highly concentrated all-purpose cleaner with a dilution that depends on the job, from vehicle exteriors and textiles to workshop floors. Koch-Chemie specifies 1:5 to 1:30 for vehicle exteriors and engine bays, 1:10 to 1:20 for interiors and textiles, and 1:40 to 1:120 for workshop and industrial floors. These ranges cover separate tasks.

For an exterior wash, Gs isn't an automatic replacement for a shampoo suited to the surface. Choose it where alkaline cleaning makes sense and compatibility is confirmed, such as heavily soiled approved areas or a separate engine-bay clean. Stick to the relevant manufacturer's dilution range and test patch.

Green Star is also alkaline: its basic formula helps remove dirt and oil, which you then rinse or wipe away. So material compatibility matters just as much as the cleaning task. This doesn't give blanket approval for every aluminium alloy, matt finish or damaged coating. Check suitability and compatibility first.

The application instructions also distinguish how you remove residue: pressure rinse exteriors and engines thoroughly; use a damp cloth or wet-and-dry vacuum on interiors and textiles. That difference helps decide which tools to have ready. A floor-cleaning dilution doesn't transfer to bodywork.

Don't let Gs dry on a hot surface. Apply as directed, allow a short dwell time, agitate with a suitable tool if needed and remove it thoroughly. Pay particular attention to residue on vertical edges and under badges.

Using Gs on interiors or textiles changes the whole process. Tools, dilution, residue removal and drying differ from exterior work. Keep an engine-bay sprayer out of the interior. Using the same product doesn't make two areas interchangeable in terms of hygiene or material compatibility.

Foaming residue can affect extractor operation. For this, Koch-Chemie points to Koch-Chemie Koc-Entschäumer "Ken", a defoamer for the cleaning machine. This special case sits outside a paintwork wash, but shows why you need to read all-purpose cleaner instructions in the context of the equipment you're using.

Keep Mehrzweckreiniger out of the paintwork wash bucket

Mehrzweckreiniger Mzr is intended for alkali-resistant textiles and plastics: surfaces that can tolerate basic cleaners. Remove the product after cleaning. Koch-Chemie specifies 1:5 to 1:50 depending on the dirt. That material list explains why you shouldn't use Mzr as a general hand-wash shampoo across paint, glass and seals.

Use Mzr in its own working area. Apply as directed, allow a short dwell time and work with a brush or cloth if needed. Lift the loosened dirt with a damp cloth or wet-and-dry vacuum. The job ends with removal and drying, rather than a quick pressure rinse of the entire bodywork.

Confirm alkali resistance first. The words “multi-purpose” don't give blanket approval for delicate textiles, coated trim, screens, leather or unknown surfaces. Let a small test patch dry fully: tide marks and colour changes can be hard to spot when wet.

Keeping these jobs separate helps with the whole car care routine. Don't take the cloth you're using for exterior pre-washing and contact washing into the interior. Keep Mzr tools with their assigned materials. That keeps road grit out of the cabin and interior dressing residue out of the paintwork wash.

Mehrzweckreiniger Mzr is offered in sizes including 1000 ml / 1 litre and containers of 11, 21 and 225 kilograms. Size doesn't change the dilution range or material limits. Bulk containers need controlled dispensing, clear labelling and a demonstrated rate of use. A lower cost per litre isn't a reason to use a product on a surface.

The selection shows how broad vehicle washing is. It covers more than exterior paint, but not everything belongs in the same bucket. Mzr has a separate interior and specialist role, while Vb and Gs illustrate exterior pre-cleaning and problem-area cleaning.

After using Mzr, check that the area is dry, residue-free and in the right condition for that material. A damp seat, foam in a seam or cleaner film on a contact surface means the job isn't finished. Only then clean the tools and return them to their own storage group.

Contact washing starts once the particle load is reduced

With a conventional wash, rinse away loosened dirt and pre-wash cleaner thoroughly before a clean wash tool touches the paint and the contact wash begins. Don't leave concentrated foam in gaps, mirror housings, number plate surrounds or lower edges. The run-off should become visibly clearer. Without a measuring system, there's no precise laboratory threshold to claim.

Only now should a clean wash tool touch the paint. Work from the cleaner upper areas down to the dirtier lower sections. Check the wash tool and solution regularly. If you see particles, rinse or replace them rather than pressing harder and carrying on.

Straight passes make it easier to keep track of where your tool has been. Circular movements don't increase the chemical action; they drag any trapped particle in more directions. Ease off the pressure around edges, badges and sharp transitions.

Give wheels and tyres their own tools. Keep brake dust from the wheel barrels out of the paintwork bucket and wash mitt. Choose a wheel cleaner to suit the finish here too. An acid-free, alkaline or acidic cleaner isn't an automatic next step after Vb or Gs.

Don't let the wash solution dry on the surface. Wash and rinse large vehicles in sections. If the shade doesn't cover the whole area, work on a smaller section rather than rushing and losing control of the process.

After the contact stage of a conventional wash, rinse thoroughly with clean water. Direct the water so product and dirt can escape from gaps. Fuel flaps, door handles, mirror undersides, grilles and number plate holders are typical places where water and residue collect.

Mark any stubborn spot left after this stage and assess it separately later. Don't tackle tar, iron fallout or water spots by rubbing harder with your wash tool. That keeps the main wash gentle on the materials and gives specialist treatment a clear purpose.

Eight final checks help prevent drips and residue

Before drying a conventionally washed car, check these eight areas for remaining foam and dirty run-off: roof edges, mirrors, door handles, fuel flap, badges, number plate surrounds, sills and wheels. Visible foam or grey run-off means you need to keep rinsing. Hidden pockets often release their contents only when opened.

Use clean drying tools reserved for the approved surface. Work without unnecessary pressure. If a towel falls on the ground or picks up dirt from an uncleaned edge, swap it out.

Remove trapped water from gaps in a controlled way and soak it up straight away. Use compressed air or a blower only with suitable equipment and approval for its use on site. Don't blow chemicals or particles towards eyes, into the interior or onto areas you've already dried.

Inspect the dry paint from different angles. Look for residue, water trails, existing damage that has become visible and contamination that still needs specialist treatment. Wet gloss doesn't mean the finish is ready to sign off.

Only now assess the existing protection. Uneven beading can mean residue, dirt or an actual change in the protection. Don't cover up the diagnosis with a random care product. Applying fresh protection calls for its own preparation process.

Clean tools separately by working area: paintwork wash tools, wheel tools, Gs/Vb sprayers and Mzr interior tools. Take bottles with unreadable labels, damaged seals and contaminated cloths out of use. Mark mixes with their date and ratio.

Record the products, mixes, unusual areas and any specialist work still needed. At the next wash, you can repeat the steps that worked without assuming that a previous compatibility check also covers a different vehicle.

That keeps the conventional wet wash a controlled approach to car washing: check the condition, chemically loosen the dirt, rinse fully, start contact washing only after reducing the particle load, open water traps and inspect the dry vehicle in eight areas.