Koch-Chemie Heavy Cut "H9.02" Coarse Grinding Polish 250ml

Polishing deep scratches from clear coat with Koch-Chemie Heavy Cut H9.02

What is Koch-Chemie Heavy Cut H9.02? A silicone oil-free, coarse abrasive polish with an abrasive grade of 9.0 and a gloss grade of 6.0, which machine-removes sanding marks up to 1,200 grit, deep scratches, and weathering from the paint. Not suitable as a finish polish, for hot surfaces, or for inexperienced first-time polishers without paint thickness measurement.

Koch-Chemie Heavy Cut H9.02 is a coarse abrasive polish from Koch-Chemie with extremely homogeneous aluminum oxide abrasive particles that mechanically remove deep scratches, severe weathering, paint overspray, and sanding marks up to 1,200 grit from the clear coat. The particles disintegrate during the polishing process until translucent and work for so long without burning that a panel can be fully corrected without re-dosing.

This distinguishes the H9.02 from classic rubbing compounds: instead of large, coarse abrasive particles in wax carriers, the formulation works with a uniformly coordinated particle size distribution that breaks down during polishing and thus automatically becomes finer in the second working phase. The result is a significantly higher gloss level with the same abrasion performance — fewer holograms after the first step and often a polishing start that requires only one subsequent step. In the system of Koch-Chemie polishes, the H9.02 is the coarse correction stage, on which finely tuned finish products are built.

• Abrasive grade 9.0 with gloss grade 6.0. The H9.02 achieves a significantly cleaner gloss with the same abrasion performance as the previous version H9.01 (gloss grade was 5.0). The polish removes sanding marks up to P1200 grit in one pass, and 50-µm scratches in the clear coat are leveled in two to three passes. After this step, a single follow-up polish with Micro Cut M3.02 is sufficient in many cases.
• Silicone oil-free and VOC-reduced processability. Without silicone oil, no release agent residues remain in the paint that would repel a subsequent ceramic coating or wet coating. Dust formation is practically zero with proper application, because the aluminum oxide remains bound in the disintegrating phase instead of atomizing.
• Two pad options for two levels of severity. With the lamb's wool pad and rotary polisher, you remove sanding marks from P1200 to P2500 — maximum abrasion performance in minimum time. With the Heavy Cut Foam Pad Red in the 2024 design, you can remove sanding marks from P1500 to P3000 even with eccentric polishers, which significantly simplifies handling for private detailers with GA6/DA-style machines.

Practical tip from Detailing1: The most common mistake with H9.02 is too little polish on the first pass and too much on all subsequent ones. When first priming a fresh pad, saturate the entire pad — only then will the abrasive particles and pad truly work together. From the second section, 3 to 5 pea-sized drops per 40×40 cm panel are sufficient. If you flood half the pad again in the second section, you will end up with a layer of superfluous abrasive residue that noticeably reduces the gloss level.

Cold paint. Saturate pad. Until translucent.

Heavy Cut H9.02 should only be used on cold, dry, and contamination-free paint. Residual contamination acts as an abrasive and creates new scratches.

Before each polishing round, the paint should be degreased, preferably with an IPA cleaner from the Prep segment, to eliminate wax residues beforehand. The manufacturer gives clear priority for machine selection: rotary polisher at medium speed for maximum abrasion performance.

The 2024 generation of Heavy Cut pads now also allows use with eccentric polishers (DA polishers) — the gloss level remains comparable, but the abrasion time per panel increases by approximately 20 percent. On a fresh pad, apply an even film when priming, spread it with finger pressure when the machine is off, and then start at level 1 to 2.

Using a cross-hatch pattern with moderate pressure, work a 40 by 40 centimeter panel until the polish becomes translucent. This is the point at which the abrasive particles have completely disintegrated and the aluminum oxide has reached its maximum fineness.

Before this point, the grit removes too much and leaves a rough microstructure; after this point, the pad works dry and creates holograms. Two to three section passes per panel are standard; for more severe defects, it's better to reduce the panel size than to extend the working time.

Remove residues with a clean, edgeless microfiber cloth — don't rub, just wipe. Between panels, check the pad for saturation: if it's sticky and shiny, loosen it with a pad-cleaning brush; if it's caked, change it instead of fighting on.

Abrasive grade 9.0 removes P1200. Not deep enough for primer.

Koch-Chemie Heavy Cut H9.02 is a correction polish, not a repair. Anything within the clear coat thickness — swirls from car washes, roller marks, sanding marks after wet sanding up to P1200, water spot etching, light bird dropping etching, UV matting — can be corrected in one to three passes. Anything that already reaches into the paint layer or primer cannot be repaired with any polish in the world.

A paint thickness gauge is mandatory for serious work with abrasive grade 9. Modern OEM clear coats are between 40 and 60 micrometers; a single H9.02 pass removes 1 to 3 micrometers, depending on the pad and pressure. Those who work without measurement and correct three times can quickly hit the paint layer on jet-black clear coats sooner than expected — and then neither finish polish nor sealant will help, only a repaint.

The honest limits: Bitumen, tar, or silicone stains do not react chemically with aluminum oxide — for that, you need a tar remover before polishing. Very soft Japanese clear coats (Toyota White, some Mazda Red tones) can quickly tip into the hologram phase with the lamb's wool pad; here, it's better to start directly with the Foam Pad Red.

For fine correction of medium scratches, the H9.02 is oversized — for that, the Fine Cut F6.01 is the right tool. If deep defects are present: H9.02 in the first step. If car wash scratches up to P2500 are the problem: F6.01 is completely sufficient.

For serious corrections, not for summer refreshes.

The Koch-Chemie Heavy Cut H9.02 is the entry-level product for anyone who practices paint correction as a craft. For the occasional polisher, it is oversized.

The target group includes ambitious private detailers with rotary or DA polishers, semi-commercial detailers with regular fleet contracts, and workshops that recondition used vehicles for resale. Anyone who refreshes their new car once a year will do much better with a finer polish like the F6.01 or an all-round polish.

Economically, the 250 ml bottle is already the standard container for private use: at 2 to 3 milliliters consumption per panel, it lasts for about 100 to 125 panels or approximately three to four complete corrections — this corresponds to a material cost of about 14 to 17 cents per panel, including initial priming of the pad. The 1-liter bottle pays off from the tenth correction job per year, the 5-liter canister is a workshop container for businesses with continuous utilization.

In Detailing1 practice, the H9.02 never stands alone — it is step 1 in a two-to-three-stage polishing system. The typical Koch-Chemie workflow: H9.02 on Heavy Cut Pad Red for coarse correction, Fine Cut F6.01 on Fine Cut Foam Pad Yellow for leveling the abrasive structure, Micro Cut M3.02 for hologram removal. Those who skip step 3 accept visible micro-sanding patterns on dark paints. Over 87 percent of our H9.02 buyers order the F6.01 in the same shopping cart — precisely for this reason.

However, the strongest lever for a clean result is neither the polish nor the pad, but the paint condition before the first drop. Clean preparation — clay bar, IPA wipedown, masking off trim — saves an average of one complete polishing pass.

But the best H9.02 tip from the workshop comes at the end: after polishing, wipe the paint again with IPA before sealing. Otherwise, the remaining oils from the pad are enough to shorten the durability of a ceramic coating by 30 to 40 percent — and you'll only notice that three months later. After the session, store pads damp in a bucket with warm water and pad cleaner, do not let them dry — that halves their lifespan.

Application of Koch-Chemie Heavy Cut H9.02

Prep, Prime, Polish to Translucency

Before the first drop hits the pad, the paint must be washed, decontaminated (clay bar if necessary), and degreased with an IPA cleaner. Wax residues or silicone remnants from prior treatments would otherwise react with the polish and cause irregular abrasive action.

When priming a fresh Heavy Cut Pad or lamb's wool pad for the first time, apply the polish evenly over the entire pad and massage it into the foam structure with your finger. From the second section onwards, 3 to 5 pea-sized drops per 40x40 cm panel are sufficient.

Place the machine onto the panel while it is switched off, distribute the polish evenly on speed 1 to 2, then increase to working speed (medium). Work in a cross-hatch pattern with moderate pressure until the polish becomes translucent — at this point, the aluminum oxide has fully broken down and reached its finest phase.

Two to three section passes per panel are standard. Wipe off residues with a clean, edgeless microfiber cloth. Coarse correction is followed by fine correction with Fine Cut F6.01 and finishing with Micro Cut M3.02.

Notes: H9.02 is not suitable for hot surfaces or direct sunlight — the pad would run dry and create holograms. Very soft Japanese clear coats should only be treated with the Red Foam Pad, not with lamb's wool. Before sealing, wipe with IPA; otherwise, the durability of the ceramic coating will suffer by 30 to 40 percent. Shake well before use. Store frost-free between 5 and 30 °C, use within 24 months after opening. Keep pads moist in pad cleaner water; do not let them dry out.