Koch-Chemie Heavy Quick Cut "B9.01" Heavy Cutting Compound 1000ml

Knock out deep scratches and heavy oxidation in one step — with the Koch-Chemie Heavy Quick Cut "B9.01" Heavy Cutting Compound

The Koch-Chemie Heavy Quick Cut "B9.01" is a powerful cutting compound with cut grade 9.0 for machine correction of deep scratches, heavy oxidation and coarse sanding marks from P1500 grit upward — silicone-oil-free, suitable for all paint types and built to be the first stage in Koch-Chemie's multi-step polishing process.

• Cut grade 9.0 — the most aggressive cut in the polishing range — for deep scratches, heavy oxidation and coarse sanding marks from P1500.
• Silicone-oil-free, plays nice with every coating — no silicone fillers that mask paint defects instead of correcting them.
• Low dust and sling — built for clean work with rotary and dual-action machines, without throwing product everywhere.

What do you actually need a heavy cut compound for — and when is it the right call?

In the Koch-Chemie polishing system, the Heavy Quick Cut B9.01 is the heaviest hitter in the lineup. With a cut grade of 9.0, it's built for paint that finer compounds like the Fine Cut F6.01 or the Lack-Polish range simply won't cut deep enough on. Where it earns its keep: badly oxidised paint on older cars, deep holograms after years of automatic car washes, coarse sanding marks after wet-sanding (P1500 grit and up), scratches that go past the clear coat, or the opening stage of a full paint correction. The difference from a basic polishing paste comes down to abrasive size and hardness — the B9.01 actually removes material instead of just filling defects. That's why you always follow it up: after the B9.01 comes a refining step with the Fine Cut F6.01 or the Micro Cut & Finish P3.01, to polish out the micro-scratches the heavy cut leaves behind.

Machine choice and pad pairing for maximum cut

The B9.01 hits hardest on a rotary polisher with a heavy cut pad (firm foam or wool). Rotaries build more heat and friction through their combined spin-and-travel motion — which fires up the B9.01's abrasives more effectively. You can run the B9.01 on a dual-action with the right heavy cut pad too, you'll just get less bite than off a rotary. Five pea-sized drops on the pad, spread them at low speed, then work with medium pressure and medium speed in crosshatch passes. Don't let the compound flash off and dry on the panel.

Silicone-oil-free — why that matters for proper paint correction

A lot of cheaper cutting compounds lean on silicone oils as fillers: they visually hide micro-scratches without actually removing them — it looks fresh, but the defects are still there and resurface a few weeks down the line. Silicone oils also mess with the bond of sealants and ceramic coatings. The Koch-Chemie B9.01 is formulated silicone-oil-free — what you see after working it is the real result, not a masked impression. Even so, degrease with the Panel Preparation Spray PPS before you seal after the B9.01 — even silicone-free compounds leave carrier residue on the paint.

Detailing1's tip from the shop: Always start the B9.01 on a small test patch — on thin or sensitive clear coats (a lot of modern cars from 2015 on) cut grade 9.0 can burn through if you lean on it too hard or pick the wrong machine. Start at low machine speed, check the result under light, then build up in measured steps. On cars with unknown clear coat thickness, reach for the Fine Cut F6.01 instead and only bring out the B9.01 when you genuinely need that heavy material removal.

Heavy Quick Cut B9.01 head to head — when is the Fine Cut F6.01 enough?

If you're not sure whether you need the B9.01 or the Fine Cut F6.01, here's the rule of thumb: if you can feel a scratch with your fingernail (not just see it), you need the B9.01. Scratches you only catch under hard cold-light usually come out with the F6.01 or even the Micro Cut P3.01. The B9.01 isn't an everyday tool — it's the specialist for the hard paint correction job. For regular refresh work on well-kept cars, the Lack-Polish violet P2.03 is the smarter pick.

Who is the Koch-Chemie Heavy Quick Cut B9.01 right for?

For pro paint correctors and serious hobby detailers who get properly into paint correction. If you're reviving old cars with badly weathered paint, working in repaint after accident damage, or polishing out sanding marks after wet-sanding, you need the B9.01 as your first tool in the multi-step process. The 250 ml bottle is ideal for the occasional one-off job; the 1,000 ml bottle pays off for outfits doing regular paint correction work.