Koch Chemie RKB Mild Clay Bar | Soft-Grade Decontamination | Paint, Glass & Wheels

The blue one is the one to reach for

Koch Chemie make their cleaning clay in two grades, and the colour is the grade. Blue is the mild, general-purpose bar. It lifts the same bonded contamination the red one does — tree resin, insects, rust bloom, industrial fallout, tar, limescale spotting — but it is formulated to take it off without marring what is underneath. The red carries a “not for new paint” warning. The blue does not. If you are standing there unsure which you need, it is almost always this one.

Where clay still earns its place

Chemistry first, clay second. An iron remover dissolves ferrous fallout and an acid pre-wash dissolves mineral deposit, and between them they take off most of what is bonded to your paint with no mechanical contact at all. What chemistry cannot shear off — tar, resin, overspray, the stubborn physical stuff — is what clay is for. Working in that order means less claying, which means less marring.

How to use it

Never dry, and never with pressure. Shape a palm-sized piece off the bar, keep the panel genuinely wet with a dedicated clay lubricant, and glide — let the clay do the work. When the surface goes glass-smooth under your fingertips, that section is done. Fold the clay to a clean face as it picks up dirt, and if you drop it on the ground, throw it out rather than grind that grit into your paint.

Suitable for all smooth surfaces including paint and glass. Follow with your polish, sealant, wax or coating — claying strips whatever protection was there.

What you're buying

One 200 g bar of mild blue clay, Koch Chemie article 183001, made in Germany. Lubricant is sold separately and is not optional — claying dry is how paint gets marred. See the rest of the range on the Koch Chemie collection page.