Koch-Chemie Vorreiniger B "Vb" Pre-Cleaner 1000ml

The alkaline pre-wash with the Koch-Chemie Vorreiniger B

The Koch-Chemie Vorreiniger B is a highly concentrated alkaline pre-cleaner at pH 13.1 for the touchless vehicle pre-wash. Phosphate-free, VDA-compliant in Class A and B, fast-separating to ÖNORM 5106 and packing corrosion inhibitors for anodised aluminium. Not a mild snow foam for active coatings — a workshop-grade alkaline cleaner for real dirt.

Koch Chemie Vorreiniger B is a high-alkaline pre-cleaner concentrate from Koch-Chemie in Unna that chemically lifts insects, bird droppings, road grime and wheel soiling before the actual car wash. At pH 13.1, this pre-cleaner sits in the professional segment between a medium-strength foam pre-cleaner and an industrial alkaline cleaner. The mix of powerful chelating agents and special surfactants tackles organic and inorganic deposits at the same time — exactly what high-throughput wash tunnels and vehicle detailers need.

• pH 13.1 pulls off insects and brake dust in one pass. The blend of chelating agents and special surfactants works on organic deposits like insect splatter and bird droppings as well as on inorganic wheel soiling at the same time. One product replaces two steps — and that saves time, water and product.
• VDA-compliant in Class A and B. One of the few pre-cleaners with a double VDA rating: 1:300 with up to 5 minutes dwell time (Class A) or 1:30 with a maximum of 1 minute (Class B). Wash line and hand wash covered with a single product.
• Corrosion inhibitors for anodised aluminium. The inhibitors protect sensitive parts despite pH 13.1 — which matters for vehicles with visible aluminium components, alkali-resistant painted alloy wheels and chrome trim.

Detailing1's tip from the shop: Never lay the Vorreiniger B down on hot or sun-warmed surfaces. Above 30 degrees paint temperature the cleaner flashes off before the dwell time is up — leaving dull streaks that only come off with polish. Before you start, move the vehicle into the shade or rinse it down with cold water first. In full summer sun, reach for the milder Pre-Foam efficient instead, which is far more forgiving with its 1-minute maximum dwell time.

1:30 for insects. 1:300 for high pressure.

Dilution depends on how dirty the vehicle is and how you apply it. 1:30 to 1:50 for the pre-wash, 1:3 to 1:10 for heavily soiled wheels, 1:300 for self-service high-pressure units.

For the touchless pre-wash with a foam lance you work at 1:30 to 1:50. One litre of concentrate at 1:50 gives you 51 litres of ready-to-use solution — enough for roughly 20 to 25 cars in standard exterior care.

The foam lance should run at 0.8 to 1.2 litres per minute flow so the foam consistency is right and the cleaner clings to vertical panels long enough to do its job. Apply the pre-cleaner from the bottom up onto the cold, pre-wetted vehicle — that way you avoid run marks on unevenly dried panels. After 5 minutes dwell time at most (VDA Class A), rinse off thoroughly with the pressure washer.

In self-service wash bays, 1:300 is enough — that's the high-volume dilution and it cuts product use noticeably over a full year. For wheel cleaning you work at 1:3 to 1:10, sprayed straight onto the cold dry wheel, left to dwell for 1 minute at most, then rinsed. Important: don't use it on hot brake discs or warm wheels. The heat speeds up the reaction in an uncontrolled way and raises the risk of dulling on painted alloy wheels.

For wash tunnels with conveyor lines you typically run 1:100 to 1:200. Dwell time in the tunnel is usually 30 to 60 seconds, which still keeps you safely inside the VDA-B limit of 1 minute. The higher dilution cuts foam volume at the spray arch but keeps enough cleaning power thanks to the high active-ingredient concentration. With high vehicle throughput it pays to switch to the 225 kg container — a better price per litre of concentrate.

For copolymer de-waxing — stripping old preservatives before a fresh sealant — 1:5 to 1:10 is the right dilution. The Koch Chemie Vorreiniger B reliably lifts polymerised wax layers. That's a step many other alkaline pre-cleaners don't cover. After that the paint can go straight to a fresh sealant — saving a separate de-waxing step with IPA or silicone remover.

Where the workshop-grade alkaline cleaner stops. No snow foam replacement.

The Koch Chemie Vorreiniger B is not a mild foam pre-cleaner for coating-protected vehicles. pH 13.1 is workshop level — strong, uncompromising, but sensitive in use.

Its strength is on heavily soiled vehicles with insect, bird-dropping and road residue after a long motorway run or after winter. It also works reliably on baked-on brake dust on steel wheels and on alkali-resistant painted alloy wheels. The foam is functional — not the show foam you get from classic snow-foam products, but a working foam that clings to vertical panels.

Now the honest read on the limits. First, the Vorreiniger B is not friendly to active ceramic coatings. Used regularly on coating-protected vehicles it breaks the coating down faster than a pH-neutral pre-wash foam does. For vehicles with an active coating, the milder Pre-Foam efficient is the better call. Second, don't use it on polished aluminium or chrome surfaces — despite the corrosion inhibitors, pH 13.1 can dull untreated light metals. The inhibitors protect anodised alloy, not bare alloy.

Third: it is not paint-surface gentle in the sense of a hand-wash chemistry. If you look after your new car with the two-bucket method and a mild car shampoo, you don't need a Vorreiniger B in the garage. Its job starts where hand washing no longer cuts it — on heavily soiled vehicles, commercial fleets, utility vehicles and construction machinery.

Protective gear is a must, not optional. Nitrile gloves and safety glasses when mixing and applying. On skin contact, rinse straight away with plenty of water and remove residue with mild soap. Never leave the concentrate bottle open — the fumes from the alkaline cleaner irritate airways and mucous membranes on longer exposure. Close it well after use and store it frost-free and dark.

The material compatibility of the Vorreiniger B has clear limits. Allowed: steel, anodised aluminium, alkali-resistant painted surfaces, glass and standard automotive plastics. Not allowed: polished light metals, bare chrome surfaces, coloured anodised layers (risk of discolouration) and matt-painted surfaces without a protective film. When in doubt, test on an inconspicuous spot before the first application and watch it for 3 minutes — it costs little time and saves expensive damage.

Who the Vorreiniger B is for — from the pro to the home garage

The Koch Chemie Vorreiniger B is built for pros and experienced home users with know-how in alkaline chemistry. For beginners without protective gear and experience it's not the right choice.

For wash lines, vehicle detailers, workshops and self-service bay operators it's a standard tool. The 22 kg and 225 kg containers cover commercial demand. The 5 kg, 11 kg and 1 litre versions are aimed at single users, smaller workshops and experienced private buyers with their own high-pressure kit.

The 1-litre container is the right way in to test the product and the dilution on your own vehicle before moving up to larger quantities. The first time you mix it, work with a calibrated measuring jug — go by eye and most beginners land far too concentrated, which loads the material needlessly and encourages streaking.

If you want a mild, coating-friendly pre-wash foam, you're better off with the Pre-Foam efficient. If you supply express wash lines with extremely short dwell times, reach for the Pre-Wash B. If you need the strongest cleaner for baked-on oil and grease residue on engines and chassis, take the Copo Star BMP-T. The Vorreiniger B is the all-round middle of the Koch-Chemie range — phosphate-free, double VDA-compliant, fast-separating to ÖNORM 5106 and therefore also approved for biological process-water treatment systems.

And that last point is the real Detailing1 insight. Workshops with an oil separator have a chronic problem with alkaline pre-cleaners. Many products form stable emulsions that overload the separator or tip the wastewater limits.

The Vorreiniger B is tested as fast-separating to ÖNORM 5106. The emulsion breaks down again in the separator within the standard conditions, and oil and water split cleanly. If you work in a commercial setting and have to keep an eye on your wastewater requirements, the Koch Chemie Vorreiniger B gives you an alkaline chemistry that won't become a problem at the plant — a detail neither the product page nor competitor copy bothers to mention.

Application of Koch-Chemie Pre-Cleaner B

Step-by-step for a clean pre-wash

Dilute the concentrate correctly depending on the application. For standard pre-washing with a foam lance, 1:30 to 1:50 is the correct dosage; for self-service high-pressure systems, 1:300 is sufficient. For heavy insect or bird dropping contamination, stay at the lower end of the dilution range; for lighter contamination, higher dilution can be used.

The vehicle must be cold and the surface slightly moistened. On hot or sun-warmed surfaces, the cleaner will dry before the dwell time is reached. Before application, move the vehicle into the shade or pre-wet it with cold water.

Spray the application solution evenly onto the vehicle from bottom to top. This prevents runoff marks on surfaces that dry unevenly. The foam lance should operate at 0.8 to 1.2 liters per minute flow rate so that the foam consistency is correct and the cleaner adheres to vertical surfaces.

Observe the dwell time. VDA Class A allows a maximum of 5 minutes at 1:300, Class B a maximum of 1 minute at 1:30. The cleaner must under no circumstances dry out — if necessary, re-moisten with water. Then rinse thoroughly with a high-pressure cleaner, again working from bottom to top.

For wheel cleaning, work with 1:3 to 1:10, spray directly onto the cold, dry rim, let it dwell for a maximum of 1 minute, and rinse off. Do not use on hot brake discs or warm rims. For copolymer dewaxing (removal of old preservatives before a new sealant), use 1:5 to 1:10.

Notes: Do not use on polished aluminum or chrome surfaces — despite corrosion inhibitors, pH 13.1 can dull untreated light metals. Not suitable for permanent care of vehicles with active ceramic coatings. Nitrile gloves and safety glasses are mandatory. In case of skin contact, rinse immediately with plenty of water. After use, close the container tightly and store in a frost-free, dark place inaccessible to children. Shelf life when stored correctly is at least 24 months. If in doubt, test on an inconspicuous area before the first application and observe for 3 minutes.