The number that matters is cars per hour. What gets forgotten is that the building is part of the machine. Soap film hazes the walls, brake dust stains the stainless, the trench packs with grit, and the arch puts on a gray jacket one thin layer at a time. Here is the full bay reset, in order.
Do it before the season turns. Late summer into fall is the shoulder window — volume off its peak, road-film months not yet started — so you can pull a bay for half a day without losing throughput.
Step 1 — Shut Down, Clear Out, Rinse Down
Lock the bay out. Kill power to the arch, blowers, and anything you are about to soak, and follow your lockout procedure — do not skip it because you are “only spraying water.” Pull the mats, cans, hoses, and signage. Anything left inside gets cleaned twice.
Rinse the room cold, top to bottom, then sweep grit to the drain. A 24-inch head like the S.M. Arnold 24” Push Broom — gray polystyrene bristles on a 3-inch trim, built for smooth concrete — moves wash-out in one pass, and clearing grit first keeps your chemistry working on film, not mud. Glove up first: Atlantic Safety Outrageous Orange 8 Mil Nitrile Gloves run 8 mil with a raised diamond grip for wet work and a beaded cuff.
Step 2 — Mix It Right Before You Spray Anything
Most bad bay-cleaning results are dilution problems, not product problems. Too weak and you scrub twice; too strong and you burn money for nothing. Concentrates only perform at the published ratio, so measure — do not pour by eye. Build a real dilution station: the Koch-Chemie 2L Graduated Jug gives clear markings in chemical-resistant plastic, and the Koch-Chemie 5L Dispensing Pump delivers a measured dose off a 5-liter canister, shift after shift. Match the sprayer to the chemistry. The iK Alkaline 9 is engineered specifically for alkaline and aggressive chemicals — degreasers, wheel cleaners, APCs — with chemical-resistant seals, nozzle, and pump. The Hi-Tech Chemical-Resistant Trigger Sprayer handles bottle work on a 28-410 neck. Label every bottle with what is in it and at what ratio — a mystery bottle in a wash bay is a hazard, not a shortcut.
THE RULE THAT SAVES SURFACES: do not let cleaner dry, and never put it on a hot surface. Koch-Chemie prints both warnings on the data sheets for Green Star, Multi Star, and its Alkali Wheel Cleaner, and lists Green Star and Multi Star as VDA-conform class A at a maximum reaction time of 5 minutes. Work one section at a time; rinse before the clock runs out.
Step 3 — Caustic Or Non-Caustic? Check The Metal First
Inventory the metal in the room — aluminum framing, anodized trim, polished rails, painted steel, stainless — then pick your degreaser for what you will overspray. It is what separates operators who keep equipment looking new from those who dull it in a season.
Malco Potent Purple™ Super Duty Degreaser is the heavy hitter: a concentrated caustic-based cleaner Malco directs at 1:1 for concrete floors and walls, 1:2 for tires and wheels, and up to 1:15 for lighter soils, with a dwell of up to five minutes before you rinse and scrub. Malco also states plainly that it is not for use on aluminum. Respect that line.
Where aluminum is in play, run Malco Red Thunder® Biodegradable Degreaser instead — a concentrated non-caustic, biodegradable degreaser Malco lists as safe on aluminum and other soft metals, one that will not etch, discolor, or pit. Dilute 1:1 for heavy soils on concrete and wheels, 1:3 for mats, 1:5 for general work. Rinse after use.
Step 4 — Foam The Walls And Ceiling, Bottom Up
Apply from the bottom up, rinse from the top down — cleaner running down a dry wall leaves clean streaks you will never blend out. It is the most common mistake crews make. For wall panels and ceiling, Koch-Chemie Multi Star earns its place — a concentrated, phosphate- and NTA-free alkaline high-foaming pre-cleaner built for heavily frequented car washes and non-contact high-pressure washing, with corrosion inhibitors for compatibility with sensitive components such as anodized aluminum. Koch-Chemie lists precleaning strength at 1:30 to 1:50 and the pH as 13.1. Ventilate, wear eye protection, keep it off hot surfaces.
Get it on as foam so it clings. Off a hose bib, the High Limit GHF1 MTM Hydro Low Pressure Foamer runs at 145 PSI max and 1.85 GPM with an adjustable air intake; for high-volume touchless work, the iK Foam Pro 2 covers ground without dragging a hose. Agitate stubborn film with a S.M. Arnold 10” Green Fountain Brush on a 60” Hardwood Handle, which reaches ceiling panels without a ladder. Rinse top down before anything dries.
Step 5 — Stainless, Arches And Rust Bleed
Equipment gets cleaned by hand, not blasted. Cabinets, control boxes, stainless panels, and arches want a ready-to-use cleaner and a towel. Koch-Chemie Allround Surface Cleaner is formulated for smooth surfaces including stainless steel and leaves a residue- and streak-free finish: spray undiluted, let it absorb briefly, wipe with microfiber. The Rag Company RGB All-Purpose Terry towels are the right tool.
The orange-brown streaking under hardware is rust bleed, and alkaline cleaner will not touch it. Koch-Chemie Reactive Rust Remover is pH-neutral and reacts on contact, turning violet as it dissolves superficial rust, metal particles, and burnt-in brake dust. Spray undiluted, let it work roughly three to six minutes, brush if needed, rinse thoroughly. Koch-Chemie advises testing sensitive surfaces such as polished aluminum on an inconspicuous area first.
One caution on strong alkaline wheel chemistry: Koch-Chemie’s Alkali Wheel Cleaner is listed at pH 14 and explicitly not for alkali-sensitive surfaces such as polished aluminum and chrome. It is rim chemistry at 1:2 to 1:10 — not an equipment cleaner.
IF YOU RUN RECLAIM OR A SEPARATOR: read the data sheet before the sales sheet. Koch-Chemie lists both Multi Star and its Alkali Wheel Cleaner as quick-separating in accordance with ÖNORM 5106, and describes Multi Star and Green Star as optimally suited for biological service water treatment plants. Those are the lines that matter when everything you spray lands in your own pit. Local discharge rules still govern — confirm with your authority, not a label.
Step 6 — Floors, Trench And Drains
Floors come after walls, because everything you just rinsed landed on them. Koch-Chemie Green Star is purpose-built for this — a concentrated, phosphate- and solvent-free alkaline universal cleaner Koch-Chemie lists specifically for workshop floor and industrial cleaning. The published floor ratio is 1:40 to 1:120: start lean and step up only where the concrete tells you to. Its data sheet gives the pH as 12.5, and the same rules apply. Apply, let it react briefly, agitate with the push broom, rinse under high pressure. Spot-treat oil-stained pads with Potent Purple at 1:1 — or Red Thunder where aluminum is in range.
Then open the trench. Pull the grates, shovel out packed silt and gravel, hose the channel clean. It is the step everyone skips, and the one that decides how the bay drains all winter.
Step 7 — Glass, Signage And Lighting
Glass goes last, after every drop of overspray has settled. Koch-Chemie Glass Cleaner is ready to use on smooth surfaces — windows, mirrors, tiles, sheet metal — and runs off without streaking thanks to a gloss additive that improves the cloth’s wiping action. Spray undiluted and wipe with a dedicated towel like The Rag Company Premium Glass & Window Towel — never one that has touched degreaser. Same product for menu boards, pay stations, and light lenses.
Step 8 — Recommission And Set The Cadence
Before you unlock the bay, restore power, run a cycle empty, and walk the room. Check every nozzle for a clean pattern — a clogged tip is the most common reason a wash stops cleaning — and verify the dosing pumps draw. On self-serve foam, Koch-Chemie Super Foam is built for the job: Koch-Chemie recommends roughly 30–50 ml/min through self-service dosing pumps, or 1:50 to 1:100 through a foam gun.
Put it on a schedule. Clear drains daily, wipe stainless and glass weekly, foam the walls monthly, run the full teardown twice a year — ahead of winter and after it. For what comes out of the arch, our pre-soak and foam guide covers the chemistry and the 2026 car wash chemical guide covers what to stock.
The Bottom Line
A bay reset is sequence and ratios, not muscle. Mix to the published dilution, pick caustic or non-caustic by the metal you will hit, foam bottom-up and rinse top-down, hand-clean the equipment, kill the rust bleed, scrub the floor, dig the trench, finish with glass. Do it on a cadence and the building keeps earning — a clean bay is the cheapest advertising on the lot. Every surface. Every season. Every machine.