Monday, 1 June 2015

Paint Surface Acidic Contaminants Identification

Ferrous Metal - 
·         Light colored vehicles: Small rust orange dots with black in centre of stain.
·         Dark colored vehicles: Small white or silver dots with a "rainbow hue" around the particle. The surface will also feel rough to the touch.

Industrial Fallout
·         The surface feels rough to the touch and may exhibit crystalline deposits.
·         Usually ferrous metal is present, as well as water spots.

Acid Rain
·         Surface will exhibit irregular discoloured spotting.
·         Dark colored vehicles will show cloudy or grey spots where the acids have started to etch the paint.

Detailer’s Clay vs. Decontamination

Be cognizant that there are two types of paint contamination, above surface and below surface. Before the advent of detailer’s clay it was a common practice to remove paint-overspray with a one-sided razor blade and a surface lubricant or by polishing the surface with a compound / polish and a wool pad.
            a) Detailer's clay - removes paint surface contaminants i.e. it abrades the top section of an iron particle, leaving what is below the paint surface to remain. Once water and heat (reactivity) is added the below surface particulates act as a conduit and the corrosion process is started.

Detailer’s clay is essentially a malleable applicator that contains suspended abrasive particles, used with a surface lubricant it aquaplanes across the paint surface and removes surface contaminants by abrasion and then encapsulation by the malleable polymer and was originally formulated to remove paint overspray; it is also useful for removing surface contaminants that have bonded to the paint.

Detailer’s clay was originally formulated to remove paint overspray; it is also useful for removing surface contaminants that have bonded to the paint surface. It gained its reputation as a decontamination method because it was mistakenly believed that it ‘pulled’ brake / rail dust iron particulates from the paint surface. Detailer’s clay contains abrasives that will only shear any brake dust particles leaving what is below the paint surface to remain. Once water and heat (reactivity) is added the corrosion process is started.
            b) Paint decontamination systems were developed as a method of removing ferrous contamination beyond what can be removed by washing or claying alone. The only way to completely remove sintered (heat fused) ferrous iron particles is with a dedicated decontamination system that opens up the paint's micro pores to release iron particles and to neutralize the caustic compounds that have developed as a result of the particle. In one step, you can eliminate both the cause and its effects. Ongoing damage is immediately stopped and future damage is prevented by completely removing the ferrous particles.

Detailers Clay
Detailer’s clay is made from Polybutene; it was originally invented and patented in Japan in 1987. Tadao Kadate is generally acknowledged as the inventor of automotive clay resin for the removal of paint over-spray.  It is formulated with mild abrasives, a common misconception about using detailer’s clay is that it pulls contaminants from the paint, and if this were true there would be no need for it to be abrasive. Be cognizant the using a clay bar can actually add minor imperfections in your paint so it's always best to follow up with a polish to remove any clay induced micro-marring.

First used by Japanese auto manufacturers on vehicle production lines and then auto body repair shops, the technology was passed on to the US market in the late ‘90’s. Detailer's clay is now routinely used by OEM's, professional detailer's, vehicle auctions and body shops as a simple, safe way to remove paint overspray, tree sap and industrial fallout from both vehicle paint and chrome and glass surfaces

Detailer's clay and decontamination are two different processes. The abrasives 'shear' the surface contaminates, the sheared particles are then encapsulated by the clay (i.e. the top of the metallic particle leaving the rest embedded in the paint, which acts as a conduit for moisture to the various paint layers, allowing it to continue generating corrosion damage

While clay products are useful for removing paint overspray (this is what the product was originally formulated for) and cleaning surface contaminants, it cannot permeate and deep clean the pores of the paint. So unless a paint decontamination system is used; heat and moisture will react with the metallic particle and continue the corrosion process 

Brake dust or rail dust is very small, almost microscopic particles of steel, iron or their alloys. These particles carry a positive charge (due to friction) while the vehicles they land on are carrying a negative charge. The vehicle surface becomes a magnet, attracting and bonding the ferrous metal particles to the vehicle’s paint surfaces.

The corrosive chemical compounds generated then proceed to etch (corrode) the clear coat, the metallic particles (brake dust) penetrate and act as a conduit spreading the corrosives through the paint film system (and the sheet metal), which results in erosion of the paint surface, that shows on the surface as tiny rust spots (rust blooms)

Environmental damage to paint comes in a varied range of threats; acid rain, road salt, tree sap, hydrazine an extremely active acid that is found in jet fuel, industrial fallout, ultra violet radiation (UV) and other airborne contaminants are very detrimental to a vehicles paint film surface. They are all forms of environmental contamination and given the right catalyst; reactivity (heat) plus moisture, they will become acidic. During this process the metal absorbs oxygen from the water and forms iron oxide (rust).  

Given the porosity of paint they permeate the paint matrix down to body metal.
Although present on all paint surfaces, sintered brake / rail dust is most noticeable on light coloured paint surfaces, especially white. These contaminants are invisible to the naked eye, once they start to oxidise, and turn orange; this is when the problem will be brought to your attention, even on brand new vehicles.

Stages of Corrosive Paint Damage 
Stage One- Iron particulates causing surface staining leading to substrate corrosion
Stage Two - Contaminants have permeated the paint matrix causing discoloration and corrosion damage
Stage Three - Particulates and corrosive compounds causing severe damage to the paints resin (binder) system

Signs of Paint Surface Contamination
          Dark coloured specks
          Brown or Orange (rust) coloured stains or specks
          Yellow stains
          Small metal coloured flecks
          Rough texture
          ‘Water spots’ or marks
          Surface etching
          Paint ‘stains

In this case, paint care not only serves aesthetics, but also helps preserve the vehicle and its resale value
Post Decontamination / Neutralization

a)      Post Decontamination or surface contamination removal: P21S® Total Auto Wash,  can be diluted solution 3:1  and  contains surfactant detergents and d-limonene (citrus oil) a biodegradable cleaner that can also be used for the removal of tree sap, bug spatters, bird droppings, engine degreaser, wheel wells, rocker panels, floor mats and other grimy areas, this safe solvent cleaner will ensure a there are no surface contaminants

b)      Neutralization: ValuGard Acid Neutralizer (part of their decontamination system) that is a blend of acids, including Potassium hydroxide, which deep cleans painted surfaces to remove alkaline deposits and safely dissolves the alkaline salt particles bond with the paint so that they can be rinsed away. Diluted 1:8 and allow product to remain in place for 5-7 minutes (do not allow product drying on paint surface). Rinse thoroughly and then dry paint surface

Acidic Contaminants Identification

Vehicle manufacturer studies have shown that failure to remove environmental contaminants (like imbedded rail dust, acid rain, industrial fallout and other environmental contaminants) from paint film can cause premature degradation of the paint system. While clay products are useful for overspray, they cannot deep clean the surface and pores of the paint. This can only be accomplished through a thorough chemical cleaning and acid neutralization.

Surface contaminants
Based upon studies carried out by PPG, DuPont, BASF and Sherwin Williams, the average vehicle's paint system will absorb up to a pint of water into the substrate when subjected to rain or a car wash.
Superficially-adhered surface contaminants as the name implies sit above the surface of the paint. 

These contaminants become imbedded in the clear coat when the paint is subjected to heat radiation; they comprise; paint residue (oxidation) tree sap and resin, bituminous asphalt (road tar) particles of road dirt (grit) and grime, carbon emissions from catalytic converters, bird excrement, calcium, tar, oil, hard water deposits, calcium or any pollutant type substance that adheres to your paint surface, sometimes invisible the naked eye.

As they are subject to greater abrasive forces than the surrounding surfaces when a surface prep towel is rubbed over them, they are abraded away and removed.  You may be questioning at this point will the abrasives in the towel affect the surrounding paint. This can be considerably lessened   by selecting the appropriate abrasive level and using a suitable lubricant. But be aware that the surface prep towel may induce surface scratches that should be removed by polishing

Then why not simply use a surface prep towel  to remove all surface contaminants; the  answer is that a surface prep towel can be used to remove surface contaminant, but a potential problem arises in that organic contaminants (tree resin and sap,  honeydew and insect exoskeletons an), which generally comprise much larger particulates than inorganic contaminants (rail and brake dust, bitumen (tar), etc)  and therefore have greater potential to cause surface marring between the surface prep towel and the paint as the towel is moved across the paint surface.

Given that some contaminant residue (acid rain, industrial fallout, sintered brake or rail dust) are usually highly acidic and / or will permeate a paint surface, it makes far more sense to remove them chemically and neutralize the paint surface rather than by using an abrasive polish, as dissolving them using a paint decontamination system and then rinsing them away virtually eliminates the risk of causing surface scratches.

Some Decontamination Products

2.      Optimum Technologies - Ferrex
3.      CarPro – IronX
4.      Nanoskin Surface Prep Towel

Always be willing to learn; because the more you learn, the more you’ll realize what you don’t know.

It is said that knowledge is power, with the caveat that it includes access to a reliable information sources. I would like to think that these articles become an asset to anyone who is new to detailing and to professional’s alike, as well as industry experts who seek to advance their knowledge.

I hope the article are informative. By having some understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little science to help you understand how the chemicals we use react, you can achieve the results you desire.

I would appreciate it if you would share these articles as it helps other detailers further their knowledge.

Questions and/ or constructive comments are always appreciated.

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