Koch-Chemie Pre-cleaner B "Vb" Pre-cleaner 1000ml

The alkaline pre-wash with Koch-Chemie Vorreiniger B

Koch-Chemie Vorreiniger B is a highly concentrated alkaline pre-cleaner with a pH of 13.1 for touchless vehicle pre-washing. Phosphate-free, VDA-compliant Class A and B, quick-separating according to ÖNORM 5106, and with corrosion inhibitors for anodized aluminum. Not a mild snow foam for active coatings — a workshop alkaline cleaner for real dirt.

Koch Chemie Vorreiniger B is a highly alkaline pre-cleaner concentrate from Koch-Chemie in Unna, which chemically dissolves insects, bird droppings, environmental dirt, and rim contamination before the actual vehicle wash. With a pH of 13.1, the pre-cleaner operates in the workshop segment between medium-strength foam pre-cleaners and industrial alkaline cleaners. The combination of highly effective complexing agents and special surfactants simultaneously dissolves organic and inorganic deposits — typical for car washes and vehicle detailers with high throughput.

• pH 13.1 dissolves insects and brake dust simultaneously. The combination of complexing agents and special surfactants works against organic deposits like insect residues and bird droppings, as well as against inorganic rim contamination. One product replaces two steps — saving time, water, and product.
• VDA-compliant Class A and B. One of the few pre-cleaners with double VDA classification: 1:300 for up to 5 minutes exposure time (Class A) or 1:30 for a maximum of 1 minute (Class B). Car washes and hand washes are covered by one product.
• Corrosion inhibitors for anodized aluminum. The inhibitors protect sensitive components despite pH 13.1 — relevant for vehicles with visible aluminum components, alkali-resistant painted aluminum rims, and chrome applications.

Practical tip from Detailing1: Never apply Vorreiniger B to hot or sun-warmed surfaces. At paint temperatures above 30 degrees, the cleaner dries before the exposure time is reached — this leaves dull streaks that can only be removed with polish. Before application, place the vehicle in the shade or pre-wash with cold water. In direct summer sun, it's better to use the milder Pre-Foam efficient, which is significantly more tolerant with a maximum exposure time of 1 minute.

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

The dosage depends on the degree of contamination and the type of application. 1:30 to 1:50 for pre-wash, 1:3 to 1:10 for heavily soiled rims, 1:300 for self-service high-pressure systems.

For touchless pre-washing with a foam lance, you work with 1:30 to 1:50. One liter of concentrate at 1:50 yields 51 liters of ready-to-use solution — enough for about 20 to 25 passenger cars in normal exterior care.

The foam lance should operate with a flow rate of 0.8 to 1.2 liters per minute so that the foam consistency is correct and the cleaner adheres to vertical surfaces long enough to work. The pre-cleaner is applied from bottom to top to the cold, moistened vehicle — this prevents run marks on unevenly dried surfaces. After a maximum of 5 minutes exposure time (VDA Class A), rinse thoroughly with a high-pressure cleaner.

In self-service car washes, 1:300 is sufficient — this is the large-volume consumer dosage and significantly reduces product consumption over the year. For rim cleaning, you work with 1:3 to 1:10, sprayed directly onto the cold, dry rim, allowed to act for a maximum of 1 minute, then rinsed. Important: do not use on hot brake discs or warm rims. Heat accelerates the reaction uncontrollably and increases the risk of matting on painted aluminum rims.

For car washes with tunnel systems, you typically work at 1:100 to 1:200. The exposure time in the tunnel is usually 30 to 60 seconds, which safely adheres to the VDA-B limit of 1 minute. The higher dilution reduces foam volume at the spray arch but maintains sufficient cleaning power due to the high active ingredient concentration. For high vehicle throughput, switching to the 225 kg container is worthwhile — a price advantage per liter of concentrate.

For copolymer dewaxing — i.e., removing old preservatives before a new sealant — 1:5 to 1:10 is the correct dilution. Koch Chemie Vorreiniger B reliably dissolves polymerized wax layers. This is a step that many other alkaline pre-cleaners do not cover. The paint can then be treated directly with a new sealant — saving a separate dewaxing step with IPA or silicone remover.

Limits of the workshop alkaline cleaner. No snow foam replacement.

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 application.

Its strength lies in heavily soiled vehicles with insect, bird dropping, and environmental residues after a long highway drive or after winter. It also works reliably on stubborn brake dust on steel rims and alkali-resistant painted aluminum rims. The foaming is functional — not an optical show foam like with classic snow foam products, but a working foam that adheres to vertical surfaces.

An honest assessment of its limitations. First, Vorreiniger B is not friendly to active ceramic coatings. With regular use on coating-protected vehicles, it degrades the coating faster than a pH-neutral pre-wash foam. For vehicles with an active sealant, the milder Pre-Foam efficient is the better choice. Second, do not use it on polished aluminum or chrome surfaces — despite corrosion inhibitors, pH 13.1 can dull untreated light metals. The inhibitors protect anodized aluminum, not open aluminum.

Third: It is not paint-surface friendly in the sense of hand wash chemicals. If you maintain your new car with the two-bucket method and mild car shampoo, you don't need Vorreiniger B in the garage. Its area of application begins where hand washing is no longer sufficient — with heavily soiled vehicles, commercial fleets, utility vehicles, and construction machinery.

Protective equipment is mandatory, not optional. Nitrile gloves and safety glasses when preparing and applying. In case of skin contact, rinse immediately with plenty of water and remove residues with mild soap. Never leave the concentrate bottle open — the vapors of the alkaline cleaner irritate respiratory tracts and mucous membranes with prolonged exposure. Close tightly after use, store frost-free and dark.

The material compatibility of Vorreiniger B has clear limits. Steel, anodized aluminum, alkali-resistant painted surfaces, glass, and standard vehicle plastics are permitted. Polished light metals, open chrome surfaces, colored anodized layers (risk of discoloration), and matte painted surfaces without a protective film are not permitted. If in doubt, test on an inconspicuous area before the first application and observe for 3 minutes — this costs little time and prevents expensive damage.

Target group Vorreiniger B from professionals to private garages

Koch Chemie Vorreiniger B is designed for professionals and experienced private users with know-how in alkaline chemistry. It is not the right choice for beginners without protective equipment and experience.

For car washes, detailers, workshops, and self-service operators, it is a standard tool. The container sizes 22 kg and 225 kg cover commercial needs. The variants 5 kg, 11 kg, and 1 liter are aimed at individual users, smaller workshops, and experienced private customers with their own high-pressure equipment.

The 1-liter container is the appropriate entry point to test the product and dosage on one's own vehicle before upgrading to larger quantities. When preparing the dosage for the first time, work with a calibrated measuring cup — with the eyeball method, most beginners end up with a much too concentrated solution, which unnecessarily increases material stress and promotes streaking.

If you are looking for a mild, coating-compatible pre-wash foam, Pre-Foam efficient is a better choice. If you supply express car washes with extremely short exposure times, use Pre-Wash B. If you need the strongest cleaner for burnt-in oil and grease residues on engines and chassis, use Copo Star BMP-T. Vorreiniger B is the universal middle ground in the Koch-Chemie range — phosphate-free, double VDA-compliant, quick-separating according to ÖNORM 5106, and therefore also approved for biological wastewater treatment plants.

Precisely this last point is the actual Detailing1 insight. Workshops with oil separators have a chronic problem with alkaline pre-cleaners. Many products form stable emulsions that overload the separator or exceed wastewater limits.

Vorreiniger B is tested for quick separation according to ÖNORM 5106. The emulsion separates again in the separator under standard conditions, and oil and water separate cleanly. Those who work in a commercial environment and have to consider their wastewater regulations will find that Koch Chemie Vorreiniger B provides an alkaline chemical that does not become a problem for the system — a detail that neither the product page nor competitor texts 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.