Koch-Chemie Teerwäsche A "Tea" Bitumen & Tar Remover 1000ml

Dissolve tar and bitumen with Koch-Chemie Teerwäsche A — no scrubbing

What is Koch-Chemie Teerwäsche A? A solvent-based specialist cleaner built on C10–C13 hydrocarbons that chemically loosens tar, bitumen, oil and grease residue — neat on a dry surface, 30 seconds to 3 minutes dwell time, then rinsed off with a pressure washer. Carries Daimler approval and is free of halogenated hydrocarbons. Not suitable for rubber, EPDM seals, soft plastic trim or freshly sealed paint.

The Koch-Chemie Teerwäsche A is a solvent-based tar and bitumen remover with Daimler approval that lifts stubborn road residue off solvent-resistant surfaces without ever touching the paint mechanically. The active mix — C10–C13 n-alkanes, isoalkanes and cycloalkanes with under 2 percent aromatics — breaks down the molecular chains in bitumen and tar chemically. The residue runs off in streaks and you either steam it away with a pressure washer or wipe it off with a microfibre cloth.

Free of halogenated hydrocarbons, which makes it far kinder to materials than a lot of the old-school tar removers that came out of the workshop drums back in the 90s. Available in 1 litre, 10 litre and 20 litre — plus a 2-pack and 3-pack for when you go through it. Alongside the alkane mix, the formula carries a share of 2-butoxyethanol as a coupling agent: it improves wetting on slick paint and keeps the product workable even at cooler workshop temperatures. For indoor use, plan for ventilation above three air changes per hour, and eye protection is a must for any overhead work.

• Chemistry, not elbow grease. You can't polish tar out — scrubbing drags the particles across the paint and leaves swirls behind. Teerwäsche A softens the bituminous residue within 30 to 180 seconds to the point where it runs off or comes up on the cloth in one pass. The brush stays in the bucket.
• Daimler approval as a green light for workshop use. Koch-Chemie works closely with the car industry. The Daimler approval isn't a marketing sticker — it means the product is officially cleared for use on Daimler paint and underbody materials. For workshops tied to a manufacturer, that's a practical argument.
• Free of halogenated hydrocarbons. Older tar removers often lean on trichloroethylene or perchloroethylene — both heavily pungent, a health concern, and barely approvable in a workshop these days. Teerwäsche A works with a modern hydrocarbon mix that's workable in well-ventilated rooms from about 15 °C upward.

Day-to-day from Detailing1: Teerwäsche A doesn't just dissolve tar — it lifts the wax or sealant underneath right along with it. That's the point manufacturers and competitors rarely mention. If you do nothing after pulling the tar, you're left with unprotected paint that takes on fallout and water spots with no barrier. So always plan it in as the first step of a combined treatment: tar wash → normal wash with a pH-neutral shampoo → re-seal with a spray sealant or wax. For a spot job (a few tar specks on the sill) a quick detailer is enough as local protection. For a full exterior treatment including re-sealing, budget about 45 minutes on a mid-size car.

Spray it on neat. Short dwell. Steam it off.

The application is deliberately simple. Lay Teerwäsche A on neat onto the dry, cool surface — either straight from the 1-litre bottle with the Canyon spray head CHS-3AN or from a tough workshop spray bottle. A wet surface dilutes the solvent and cuts the cleaning power right down — when washing, do the tar wash first, then the shampoo.

Dwell time runs 30 seconds to 3 minutes — depending on how thick the tar layer is. You can see it working: the tar dissolves into brownish-black streaks and runs down vertical surfaces. Once that happens, rinse straight off with a strong jet of water or wipe down with a clean microfibre cloth. A 1000 ml bottle covers about 4 to 6 full vehicle sides with moderate tar build-up.

On larger areas, don't let it dry out — in direct sun or on hot paint over 25 °C the solvent flashes off too fast and leaves an oily film that only comes off at the follow-up wash. For underbody or wheel-arch work on commercial vehicles, the 10 or 20 litre version is the right call.

There you apply it over a wide area with a pump sprayer and then steam it off with the pressure washer at about 120 bar. On stubborn, dried-on bitumen spots after a building-site run, a second application helps more than a longer dwell on the first pass — the solvent is saturated after about 3 minutes and stops working.

It dissolves tar. And wax too.

Teerwäsche A goes after every organic coating sitting on the paint. That's how it works — and at the same time it's the one catch for anyone who reaches for it without planning ahead. Carnauba waxes, synthetic polymer-based sealants and most quick detailers dissolve right off on contact with the hydrocarbon blend. That's not a flaw in the product either, it's chemistry: whatever dissolves bitumen dissolves wax, because both sit on similar organic molecular structures.

In practice that means two things. First: every tar wash is followed by a full paint wash with a pH-neutral shampoo to neutralise the solvent residue. Second: the treated spot needs a fresh layer of protection.

If you only treat small specks on the side sill, you can touch up with a spot wax or detailer. If you're cleaning whole panels or the underbody, build the re-seal in as a fixed part of the workflow. SiO₂-based ceramic coatings usually aren't fully wrecked by a tar-wash treatment, but they lose noticeable hydrophobicity — a topper or detailer brings them back up to level.

Teerwäsche A isn't suitable for unpainted soft plastics, rubber seals and EPDM profiles. The solvent swells rubber on longer contact and can dull plastics. The usual victims are window seals, door rubbers and black plastic trim on older vehicles.

Don't spray it over a wide area on those surfaces — if overspray happens, rinse it off with water within 60 seconds. On fresh wraps and PPF (paint protection film) test on a hidden spot first. Plenty of PPF coatings handle short contact times under 30 seconds but react sensitively to longer dwell.

When the tar wash fits and when it doesn't

Teerwäsche A is the right call when you need to shift genuine road tar, bitumen specks after driving through a building site, asphalt residue on wheel arches or dried-on oil films around the underbody. It's also built for the regular cleaning of car-wash brushes and workshop floors — wherever it's not paint cosmetics but real chemical dissolving power that's wanted. In the spring season after winter it's standard for underbody prep, when tar-and-salt mixes have built up over months.

On insect residue, though, it's not the first choice. Insect proteins are organic, but structured differently — enzymatic cleaners like the insect remover work more precisely there and are kinder to paint. If you've got both at once — tar on the sill, bugs on the front end — treat the two areas separately with the right product for each. Trying to crack everything with one all-rounder usually ends in more rework. Same goes for tree sap and adhesive residue: both dissolve with the tar wash, but a dedicated tree-sap remover works cleaner.

For pack size, the 1-litre bottle suits the private user and the occasional detailer planning one application per car. The 2-pack and 3-pack bring the price per litre down by roughly 5 to 15 percent — worth it if there are several cars in the household or you want the season's supply locked in.

The 10 and 20 litre canisters are workshop packs for reconditioning, underbody cleaning or fleet operations — here the buy only pays off from regular weekly use. For precise single-spot application, the 1-litre bottle with the Canyon spray head stays the most ergonomic option. The spray head delivers a precise cone instead of a mist and doses right onto the problem spot without needlessly wetting the surrounding area.

Store Teerwäsche A frost-free at room temperature. Once opened, the bottle stays stable for about 24 months as long as the cap is closed tight after use — otherwise hydrocarbon solvents slowly evaporate and the concentration drops.