Brake dust
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.
In detail
Brake dust is not dust in the ordinary sense. Friction between pad and disc throws off iron particles at high temperature along with carbon from the pad binder, and those particles arrive hot enough to embed into the wheel's coating rather than settling on it. Two things follow. It does not rinse off, because it is mechanically keyed into the finish. And it corrodes in place, producing the orange specks that make an alloy wheel look as though the wheel itself is rusting when the iron is somebody else's. The same mechanism produces the orange spotting on light-coloured vehicle paint that detailers call iron fallout. Products sold to remove it dissolve the iron chemically — acids, or chelating agents that bind iron and change colour doing it, which is the purple bleeding effect. The standards guidance for finished aluminium constrains all of them severely: aggressive alkaline and acid cleaners must never be used, named acids and fluorides must not touch anodised surfaces, and marks from mistreatment may be permanent. Frequent gentle washing prevents embedding far more effectively than any product removes it afterwards.
Why
- Brake dust is explained by Adhesion and cohesion
- Brake dust is explained by Coating thickness
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 cleaners containing named acids and fluorides must not be used on anodised surfaces, and that marks from mistreatment may be permanent. (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.
Care and Maintenance of Stainless Steel
British Stainless Steel Association, Stainless Steel Advisory Service, 2001 · Trade or professional body
Relied on for: That embedded iron particles corrode in place and appear as rust staining on a surface that is not itself corroding. (states this directly)
Verification: a person has read the passage relied on.
Read on — Sprint 29 re-read all four pages: Factors Affecting Maintenance, Maintenance Programme, Cleaning Methods with the whole of Table 1, Table 2, and Notes 1-10. Earlier sprints named both tables but carried only part of one and none of the notes. Supports a wider statement — our claim was widened. SPRINT 29 FOUND THIS UNDER-EXTRACTED WHILE ALL THREE SIGNALS CALLED IT DONE: zero representation debt, in the fully-harvested list, and honestly noted as 'read in full'. Five of Table 1's eleven rows, all of Table 2 and eight of ten notes had never reached the graph. Newly built: tannin and coffee deposits, heat discolouration, the 1% ammonia routine clearance, oxalic acid for embedded iron, and the condition-triggered domestic frequency rule. The paraphrase cap is part of the cause, and the fix is not a longer paraphrase — the facts belong in the citing records.
Last reviewed by a person on .