Originally Posted by TOGWT

As AnthonyO eluded to 'Be very careful using acids to clean wheel surfaces' some of them are very, very corrosive to both the wheel surface and YOU :nono:

Hydrofluoric Acid (SiO2):
[: is a highly toxic and corrosive solution of hydrogen fluoride in water.] Cleaning paint (inc wheel surfaces) - ten or more years ago this method was widely used by body-shops and detailers to remove water spots from paint surfaces, however, as time progressed, we started to see metallic paints darken under the clear coat.

Hydrofluoric acid is also notoriously known to react with glass. Most of us have seen what it does to the more robust acrylic or polyester powder clears used on factory aluminium wheels. First, the wheel surface obtains an opaque (cloudy) appearance, as time progresses, we observe small hairline scratches start to appear; an indication that the finish surface has been compromised, it also produces micro hairline cracks, and will eventually fail.

Most of the larger automotive paint suppliers (PPG, DuPont and BASF) do not recommend this type of chemical to be used on their paints. Stating that the acid, even if thoroughly flushed with water had already compromised the clear coat and given time would also compromise the paint system, dependant on the environment the vehicle was subjected, to over a period of 2-3 years it was possible that the clear coat would occlude (cloud) indicative of clear coat failure as the acid breaks down the paints binder system.

It also has the unique ability to dissolve almost all inorganic oxides. In the human body, hydrofluoric acid reacts with calcium and damages nerves, bone, and several organs including the heart and kidneys. It has an NFPA health rating of 3; Short exposure could cause serious temporary or residual injury even though prompt medical attention was given

Information resource - http://en.wikipedia.org/wiki/Hydrofluoric_acid
Material Data Sheet - MSDS - http://www.jtbaker.com/msds/englishhtml/H3880.htm

Notes:
a) Muriatic acid is also a form of hydrochloric acid (except the solvent)
b) Do not confuse hydrochloric acid (HCL) with hydrofluoric (HF) acid because of the similarity of names. On the skin, hydrochloric acid burns from the outside in. Hydrofluoric acid solution readily penetrates the skin and burns both skin and deeper tissues. If enough acid is absorbed, it may lethally affect the heart and nervous system.

Ammonium hydrogen fluoride NH4HF2 (or Ammonium bifluoride) is miss-classified as the safe alternative to hydrogen fluoride, once mixed with water it becomes hydrogen fluoride one of the most common, and dangerous, acid wheel cleaners used in automatic carwashes today. Its effectiveness removing brake dust and difficult contaminants from wheels is undisputed, but most chemists say Ammonium bifluoride presents an unjustifiable and potentially lethal risk to carwash operators and their employees. Ammonium bifluoride sometimes known as ammonium fluoride or ammonium hydrogen fluoride is a crystalline salt formed when ammonium hydroxide reacts with hydrogen fluoride. Through a complicated chemical reaction, it essentially becomes hydrogen fluoride when mixed with water or liquid cleaning solutions.

Similar to hydrogen fluoride, Ammonium bifluoride was originally developed for industrial uses, like etching glass, removing oxides from metals and eliminating mineral stains from stone, glass and porcelain
(See also Water acting as a catalyst for Acid, Hydrogen Fluoride (SiO2)

Information resource- Wikipedia - http://en.wikipedia.org/
Professional Carwashing & Detailing Magazine - http://www.carwash.com/article.asp?In

Originally Posted by MoeMistry (Post 4174785)

For hard to clean wheels, I've always counted on Zymol Strik. It's a safe and natural cleaner that will not harm the finish on the wheels. You let it dwell for about 20 minuts and use a cotton towel to clean the wheels. Post a pic of the current wheels and we can better diagnose the correct application.