Be cognizant that there are two types of paint contamination, 1.Above and 2. Below surface;



1. Bituminous Asphalt (tar), Industrial Fallout, Tree resin (sap) and etc) which should be removed with detailer’s clay and / or a chemical paint cleaner and ferrous oxide particles (brake / rail dust) which should be removed with a decontamination product



2. Sintered ferrous oxide particles (brake / rail dust) penetrate the paint surface and if not removed will act as a conduit to the paint matrix system. Once water and heat (reactivity) is added the corrosion process is started, often showing ‘rust spots’ (blooming) on the paint surface, light colours tend show the necessity of decontamination more that darker colours. I am referring to those small brown ferric oxides (rust spots) that just seem to get larger and larger.



Surface



Industrial Fallout [: simply a by- product of manufacturing, traffic, and factory pollution. These airborne particles settle on your paints surface causing contamination.]



Environmental Stains [: insect stains, bird droppings, tree sap, and acid rain spots are amongst the contaminants detailing clay will remove. [1]



Sub-surface



Rail Dust [: ferrous oxide FeO] from the day a new car is shipped its surface is under attack. The railcar its sitting is showered with airborne metal particles from the rails. These ferrous metal particles embed themselves into the paint and will eventually oxidize and form rust corrosion under the clear coat]



Brake Dust [: sintered ferrous oxide FeO) particles from your own and passing vehicles will also get embedded in your paint.]





The following articles show various ways of removing commonly encountered surface contaminants:-





http://www.autopia.org/forum/autopia...ml#post1499764



http://www.autopia.org/forum/autopia...ml#post1499765



http://www.autopia.org/forum/autopia...ml#post1499766



http://www.autopia.org/forum/autopia...ml#post1499767



http://www.autopia.org/forum/autopia...ml#post1499788



http://www.autopia.org/forum/autopia...carcasses.html



http://www.autopia.org/forum/autopia...ml#post1499913



http://www.autopia.org/forum/autopia...ml#post1499916



http://www.autopia.org/forum/autopia...t-surface.html



http://www.autopia.org/forum/autopia...ml#post1505182



http://www.autopia.org/forum/autopia...zed-paint.html



http://www.autopia.org/forum/autopia...ce-damage.html



http://www.autopia.org/forum/autopia...excrement.html



http://www.autopia.org/forum/autopia...lear-coat.html



http://www.autopia.org/forum/autopia...ke-odours.html





Relevent Articles



1. http://www.autopia.org/forum/autopia...rep-towel.html



2. http://www.autopia.org/forum/car-det...l-damage.html#



3. http://www.autopia.org/forum/autopia...ml#post1501707








[Edit: to add new article hyperlinks]