Bilt Hamber Korrosol | pH-Balanced Iron & Fallout Remover
What it actually is
Korrosol is a fallout remover built on sodium mercaptoacetate — sodium thioglycolate — declared at 15–25% in Bilt Hamber's own safety data sheet (CAS 367-51-1). That one line tells you nearly everything, because the active is a thiol, not an acid. Most of the iron removers on the market lean on acidity or on aggressive chelants to get bonded ferrous particles moving. Korrosol doesn't. Bilt Hamber's SDS puts it at pH 5.5–7.0 — mildly acidic to neutral. There are no strong acids and no alkalis in it.
Why it goes purple
The thiol group chelates iron. As bonded ferrous particles are coordinated and pulled into solution, the reaction throws a deep violet colour — Bilt Hamber describe it as "a side effect of the chelation process." The purple is the signal, not the mechanism: it tells you the product has found contamination and is working. Once the colour stops deepening, the reaction has run its course and it's time to rinse. What's actually happening is that insoluble iron oxide is being rendered water-soluble, so it rinses away instead of sitting embedded in your clear coat.
Where it earns its place
Use it on paint before claying — it strips the embedded iron chemically, which means the clay bar isn't dragging sharp ferrous particles across your finish and your bar lasts considerably longer. It also lifts light and flash corrosion from unpainted surfaces, because rendering iron oxide water-soluble is exactly the same job.
How to use it
Cool surfaces only. Spot test somewhere discreet first. Spray liberally and leave it to react — anywhere from 15 seconds to 5 minutes depending on temperature. When the purple stops deepening, pressure wash or rinse thoroughly. Repeat on heavier contamination. It's ready to use; no dilution.
Do not apply to chrome-look plastic wheel centres, chrome plastic or chrome films. The conductive layer can be chelated and dulled.
Handle it properly
Sodium mercaptoacetate is a skin sensitiser. Bilt Hamber classify Korrosol as H317 (may cause an allergic skin reaction), H302 (harmful if swallowed) and H319 (causes serious eye irritation). Wear nitrile gloves and eye protection, and don't breathe the spray. We'd rather tell you that plainly than sell you a fairy tale about a "totally safe" chemical — it's a well-formulated, pH-balanced product, and it still deserves respect.
Safety Data Sheet (Australia)
Download the Bilt Hamber Korrosol SDS (PDF)