Vasco Prewash Thixotropic Tar Remover Gel

Tar and asphalt don't come off in a normal wash. They sit in the bottom quarter of every panel after a resurfaced road or a wet motorway run, and the usual fix is a solvent and a lot of rubbing on paint you have just spent an hour correcting. Vasco Prewash is a thixotropic gel pre-wash and tar remover: it clings where you spray it instead of running down to the sill, so it stays on the contamination long enough to dissolve it without you touching the panel.

Why it works

• Gel consistency holds on vertical panels rather than running off, so the dwell time is real dwell time
• Non-solvent cold degreaser — it works by dwelling, not by aggressive solvent attack
• Dissolves tar, asphalt, road salt, oil and greasy road film in one application
• Contactless: spray, leave it, rinse. No mitt, no clay bar, no rubbing tar across clearcoat
• Used neat through a trigger or low-pressure sprayer — no dilution maths
• Around two to three cars per litre; the 5L is the working detailer's size

When to use it

First thing, on a dry, cool car, before any water touches it. Lower quarters, sills, behind the arches and the rear bumper are where tar collects. It is the stage before your snow foam and pre-wash, not a replacement for it — tar first, then foam, then the contact wash.

Specification

Straight from us

The dwell time is the entire product. Rinse after five minutes and you will wonder what the fuss is about; leave it an hour and the tar comes off in the rinse water. Two things people get wrong: not shaking the bottle, and spraying it onto a wet car. Past a couple of cars a year the 5L is the obvious buy — roughly a third of the per-car cost of the litre.

What it won't do

It is not a wash. Vasco Prewash lifts tar and greasy deposits but leaves general road film behind, so it always needs a foam and a contact wash after it. It will not touch bonded iron fallout either — that needs an iron fallout remover at the next stage.

Frequently asked questions

How long do I leave Vasco Prewash on the paint?
At least 30 minutes, and 45 minutes to 2 hours on heavy tar. Do not let it dry on the panel — if it starts to dry, re-mist the area and give it a few more minutes before rinsing.

Do I dilute Vasco Prewash?
No. Vasco Prewash is used neat straight from the bottle through a trigger or a low-pressure sprayer.

Is Vasco Prewash safe on ceramic coatings and wax?
Detailers use Vasco Prewash on coated cars, and it is a non-solvent product rather than an aggressive solvent tar remover. Rinse thoroughly and re-check your protection after any heavy decontamination. Keep it off rubber seals and out of direct sunlight.

Do I need to wash the car first?
No — that is the point of it. Vasco Prewash goes onto a dry, cool car before the wash, so the tar is gone before a mitt ever touches the paint.

Browse the full Vasco range at Blade Performance.