Alloy wheel
A coated aluminium casting collecting hot iron dust from the brakes. Two of the finishes it comes in are damaged by the acids sold to clean it.
Precautions
- Check the manufacturer's instructions
- Test on an inconspicuous area first
- Do not apply to a hot surface
- Wear gloves
Start here
What this is, what goes wrong with it, and where CleaningHQ can help.
Made from
What tends to go wrong
Hydrated iron oxide from corroding iron or steel. Distinguish a surface deposit, which cleans off, from active corrosion of the item itself, which does not.
Why it is difficult: Corrosion and passivation, Why old stains are harder, Adhesion and cohesion
Food heated until it carbonised and bonded to the surface. Time and softening do the work; scouring powder does the damage.
Why it is difficult: Contact time, Carbonisation, Adhesion and cohesion, Why old stains are harder
- Algaevia its material
The green film outdoors, and NOT the same organism as the mould indoors. Where it grows is the diagnosis: shade, overhanging trees, or paving that does not drain.
Why it is difficult: Moisture control and recurrence
- Dustvia its material
Mostly textile fibres and skin, held by static as much as by gravity — which is why a dry cloth on a plastic surface makes it worse.
Why it is difficult: Static and dust, Mechanical action and abrasion, Why different surfaces get different dirt, Surface roughness
- Moss and lichenvia its material
Three different organisms treated as one green problem. Where they grow tells you more about the fix than any product does.
Why it is difficult: Moisture control and recurrence, Surface roughness
- Tarnishvia its material
The only contaminant in this catalogue that is made of the surface it is on. Removing it always removes metal.
Why it is difficult: Coating thickness
- Greasevia its material
Fats and oils, which water alone cannot lift. Removed by surfactants, by heat, by solvents, or by alkalis that convert the fat into soap.
Why it is difficult: Why oil resists water, Emulsification
- Fingerprintsvia its material
Skin oils transferred by touch. A greasy soil rather than a dirty one, which is why water alone does not shift them and why they return immediately.
Why it is difficult: Surfactancy
- Road salt· no method established yet
A white tidemark on boots, carpet and car sills that is also actively corroding whatever it is sitting on.
Why it is difficult: Chloride attack, Evaporative deposition
- Brake dust· no method established yet
Hot iron particles embedded into a wheel coating, not dust sitting on it. They corrode where they land, which is why an alloy wheel appears to be rusting.
Why it is difficult: Adhesion and cohesion, Coating thickness
The science behind this: Alkali attack on light metals, Corrosion and passivation, Solvents and polymers, Mechanical action and abrasion, Polishing removes metal, Coating thickness
Part of Car exterior.
In detail
An alloy wheel is cast aluminium finished in one of several ways — painted, powder coated, lacquered, machined and lacquered, polished, or anodised — and the finish decides the method entirely. What accumulates on it is not ordinary dirt. Brake dust is hot iron particles embedded into the coating along with carbon from the pad, which is why it does not rinse off and why it corrodes in place, leaving orange specks that look like the wheel itself is rusting. Acidic and alkaline wheel cleaners are sold to attack that deposit and the standards guidance for finished aluminium is unambiguous about the cost: aggressive alkaline and acid cleaners must never be used on aluminium finishes, and on anodised surfaces cleaners containing trisodium phosphate, phosphoric acid, hydrochloric acid, hydrofluoric acid or fluorides must not be used at all. Marks from mistreatment may be permanent. The same document's escalation is the safe route: water at moderate pressure, then a mild detergent with brushing under uniform pressure, then a thorough rinse and dry. Two further instructions apply directly — never clean a hot wheel, and identify the finish before choosing anything.
Why
- Alloy wheel is explained by Alkali attack on light metals
- Alloy wheel is explained by Corrosion and passivation
Related
- Alloy wheel is made from Powder-coated aluminium
- Alloy wheel is made from Aluminium
- Alloy wheel is made from Lacquered metal
- Alloy wheel is commonly affected by Rust
- Alloy wheel is commonly affected by Road salt
- Alloy wheel is commonly affected by Burnt-on food and carbon deposits
- Alloy wheel is commonly affected by Brake dust
Hacks and claims involving this
- Acidic wheel cleaner on alloy wheels Disputed
Sources for this page
Sources
AAMA 609 & 610-02: Cleaning and Maintenance Guide for Architecturally Finished Aluminum
American Architectural Manufacturers Association (AAMA), 2002 · Standards body
Relied on for: That aggressive alkaline and acid cleaners must never be used on aluminium finishes, that named acids and fluorides must not be used on anodised surfaces, that marks from mistreatment may be permanent, that the escalation is water then mild detergent then rinse and dry, and that hot sun-heated surfaces must not be cleaned. (states this directly)
Verification: a person has read the passage relied on.
Read on — Read in full. Sections 3 General, 4.1 light surface soil, 4.3 organic coatings, and 5 Cleaning Precautions. Supports the claim as stated.
Last reviewed by a person on .