Late September is when the shelf gets audited. Wash volume drops, the boats come out, the combines go in, and the correction work that pays all winter starts landing in the bay. It is also when most shops discover they own four compounds that all do the same thing and nothing that finishes. Stop buying by the label. Buy by cut level.
First, Know What You Are Actually Fixing
A compound does not have a personality. It has an abrasive size and a job. The only way to pick correctly is to see the defect honestly first — which means stripping the panel and putting real light on it.
Koch-Chemie Panel Prep Spray is the step people skip. It is an alcohol-based, ready-to-use cleaner that pulls off oils, waxes and old polish residue, and Koch-Chemie states the point plainly in its own data sheet: it tests the paint for holograms and freedom from scratches at the same time. Strip the panel and the paint stops lying to you. There is a 5 L jug for shops running it all day. Then light it — a SCANGRIP Sunmatch 4 at a low angle finds the swirl depth your overheads hide.
THE ONLY NUMBERS THAT MATTER. Serious manufacturers publish the finest sanding grit their compound will erase. That figure is your buying spec. Koch-Chemie goes further and publishes a cut and gloss rating for every polish: Heavy Cut H9.02 is cut 9.0 / gloss 6.0, Fine Cut F6.01 is 6.0 / 7.0, Micro Cut M3.02 is 3.2 / 9.0. Read it left to right and the system explains itself — as cut goes down, gloss goes up. Nothing does both.
Heavy Cut: Sanded Panels And Dead Paint
This tier exists for two things — sanding marks after bodywork, and paint so far gone a medium polish just smears it around. Reach here for wash swirls and you are removing clear coat you did not need to remove.
Koch-Chemie Heavy Cut H9.02 is the benchmark. Koch-Chemie rates it to remove sanding traces up to 1,200 grain, and the reason it earns bay space is the abrasive consistency — long working time without grabbing, and very little dust. Worth knowing before you build a process around it: Koch-Chemie's own instruction is to follow H9.02 with Micro Cut M3.02. Two steps, not three.
Malco Super-Duty Heavy-Cut Compound does something H9.02 does not — Malco publishes it for gel coat as well as clear coat, clearing P1500 grit and finer on a 100% twisted white wool cutting pad. That makes it the pick for a body shop that also sees boats.
RUPES D-A Coarse is the dual-action answer. RUPES lists it as body-shop safe and optimized for BigFoot random orbital and gear-driven machines — note that rotary is not on its recommended list, unlike the rest of the RUPES range. Whichever you pick, heavy cut needs a heavy pad: Lake Country knitted lambswool or the RUPES D-A Coarse wool pad do work no foam pad will.
Medium Cut: The Eighty Percent Job
Tunnel swirls, snow-brush scratches, light oxidation, road-film etching on a fleet hood. This is where the majority of real work lives, and where most shops over-buy on cut.
Koch-Chemie Fine Cut F6.01 is the single most useful bottle in this guide. Aluminium-oxide abrasive, rated to erase 2500-grade sanding marks, and specifically formulated for scratch-resistant clears — the hard paint that makes cheap compounds skate. Koch-Chemie lists it for cars, commercial vehicles and motorcycles, which is why it does not flinch on a semi hood or a sprayer boom. It is the chain we run most: F6.01, then M3.02. There is a 250 ml bottle if you want to test before committing a liter.
Malco Epic Medium Duty Compound is the production pick. Malco publishes it to P2500 sand scratches, cutting and polishing in one step on an orbital, water-based, dust-free, and 100% body shop safe — no waxes, fillers or silicones. That last part is not marketing; it is why a refinish shop can use it without poisoning a repaint. Step up to Epic Heavy Duty (to P1500, same body-shop-safe formula) when the front clip has taken real abuse. Malco Tru-Grit is the one-bottle-for-the-whole-bay option, published as compatible with all paint systems, aged or fresh.
Pads: Lake Country HDO CCS Blue for the heavier end, HDO CCS Orange for the rest. Our Lake Country pad guide covers how much of the cut comes from the foam.
Finish: Where The Gloss Comes From
Nobody sees your cutting step. They see this one. Skip it and the panel reads hazy under showroom light no matter how clean the cut was.
Koch-Chemie Micro Cut M3.02 is the end of both Koch-Chemie chains. Rated to P3000, cut 3.2 / gloss 9.0, and the claim worth reading twice: Koch-Chemie states holograms and fine scratches are removed mechanically rather than covered over. Polish until the film goes transparent — that is the aluminium oxide fully broken down. Koch-Chemie's one caution: do not cross-use a Micro Cut pad with other products.
RUPES UNO Pure is the jeweling bottle. RUPES publishes it as body-shop safe with no intentional filling ingredients or protection properties — the finish is pure and ready for coating — and it runs on rotary, random orbital and gear-driven machines. If you coat vehicles, a filler-free finishing polish is not optional.
Malco covers this tier two ways: Epic Finishing Polish, the Epic system's finishing step for fine scratches, swirls, water spots and light oxidation, and Buff Lite II Finishing Creme, published as a light compound for P2000 grit and finer. Finish on Lake Country HDO CCS Black and wipe with a Rag Company Eagle 600 — a cheap towel undoes a good finishing polish in one pass.
One-Steps: When Good Enough Is The Right Call
A reconditioning lot, a fleet of 40 trucks, a trade-in that needs to look sold by Thursday. Multi-step correction is the wrong tool for volume.
Malco Accelerate is the strongest case here — Malco publishes it as a one-step that removes light to medium defects and leaves up to 90 days of protection, with a long working window and dust-free application, so you can do a whole vehicle before wiping. Malco Velocity One-Step Polish and Wax is the same logic aimed at retail work, also rated up to 90 days. For dark paint, Malco Nanocare Polishing Crème is Malco's one-step formulated specifically for darker colored vehicles. Koch-Chemie's single-step answer is ShineSpeedPolish — maintain and protect in one pass, by hand or machine.
For tunnel operators, Koch-Chemie NanoCrystal Polish is a different animal: a foaming care polish for the arch, VDA conform to class A, built to leave gloss and prep the surface for drying. Not correction — care. Know which one you are buying.
Gel Coat, Equipment And Everything That Is Not A Car
Gel coat is thicker and harder than clear coat, and it eats automotive compounds. RUPES XC-2 Xtra Cut is built for it — formulated for rapid defect removal on gel coat and other high-solid industrial finishes, hard paint, countertops and aviation work, and it runs on both dual-action and rotary. RUPES Marine Extra Cut Compound is the dedicated marine cutter for sanding marks on production gel coat and severely oxidized hulls; pair it with a Lake Country Marine Master cutting pad. Malco Super-Duty is the third valid gel coat option.
On agricultural and fleet iron the paint is usually single-stage and chalked rather than swirled. F6.01 on a wool or blue pad brings a faded combine hood or a ten-year-old grain trailer back further than anyone expects — and on a machine that big, a one-step is often the correct answer, not a compromise.
Three Shelves That Cover Real Work
Weekend and enthusiast. F6.01 250 ml, M3.02, HDO CCS Orange and Black, Panel Prep Spray. Two bottles, two pads — that handles almost every driveway car in the Midwest.
Working detail shop. Add H9.02 and knitted lambswool, plus Epic Medium Duty for production days. Run Koch-Chemie's two published chains — H9.02 to M3.02 for sanded or dead paint, F6.01 to M3.02 for everything else — and finish coated vehicles on UNO Pure.
Recon, fleet and high volume. Accelerate or Velocity as the default, Epic Medium Duty for cars needing real correction, Epic Heavy Duty for abused front clips.
The Bottom Line
The best polishing compound is the least aggressive one that removes the defect in one pass. Everything above that is clear coat you are never getting back. Buy a medium and a finish first — F6.01 and M3.02 cover more paying work than any heavy cut ever will — then add heavy cut when sanded panels show up. For the full Koch-Chemie lineup, read our Koch-Chemie polish system guide. If it runs, rolls, or floats — we help it shine.