Sunday, 14 April 2013

Detailing and Care of White and Light colored Paint


               



Light colored paint tends to turn grey with time (an unsightly grey film), this is especially true of white or pearl colours  This is due to road oil and dirt becoming ingrained in the paint, a chemical cleaner and a polish will normally rectify this. The 'yellowing' is paint oxidation caused by ultra violet radiation.

There are approximately 10-20 different colours that are mixed with white to produce various shades. The colour formula for white paint is a mix of red, yellow, green, blue and black in various percentages to arrive at the required ‘tint’ colour (i.e. arctic white, brilliant white, etc) Ultra violet radiation sometimes places an emphasis on the yellow and creates a tarnished look, in a similar way a red paint turns to pink due to the red oxide content in the paints colour formula (this is more pronounced in older style paint like single pack acrylic or cellulose based paint rather than modern clear on base 2K pack paints

With all vehicles a regular routine of cleaning the paint surface is important; more so with light coloured paint as dirt is more noticeable than on darker colours. Clean paint surface with a chemical paint cleaner and / or detailer’s clay and then use an abrasive polish to remove any oxidation.

Most people may think white paint won’t show paint defects when clean, actually it will, you just have to look harder than darker colour paint like a black car; but they are there as the light will refract as opposed to reflect. A level clear is just as desirable on a white/silver or light colour vehicle

Cleaning Process

With all vehicles a regular routine of cleaning the paint surface is important; more so with light coloured paint as dirt is more noticeable than on darker colours.
Most people may think white or silver paint won’t show paint defects when clean, actually it will, you just have to look harder than darker colour paint like a black car; but they are there as the light will refract as opposed to reflect. A level clear is just as desirable on a white/silver or light colour car
With all vehicles a regular routine of cleaning the paint surface is important; more so with light colour paint as dirt is more noticeable than on darker colours. Clean paint surface with a chemical paint cleaner and / or detailer’s clay and then use an abrasive polish to remove any oxidation.
1.      Nanoskin Towel or Detailers clay to remove above surface contaminants

2.      ValuGuard Decontamination System to remove below surface contamination. This preventative measure puts a stop to corrosion, and contains unique chemical ingredients that effectively dissolve the sintered iron by forming water soluble iron complex. For use on car paint, wheels and glass surfaces (safe for all wheel finishes including painted aluminium and alloys) to remove iron filings and ferrous-based contaminants.

 Automotive paint is porous; by using an acid-based solution on the paint surface the micro-fissures (‘pores’) are permeated. This releases ferrous particles and caustic compounds that have developed in the paint's subsurface; the exothermic reaction agitates and loosens the particles allowing them to be rinsed away. Unlike clay that only removes the particulates that protrude from the paint by abrasion

 3.      Klasse All-in-one (AIO) a chemical paint cleaner to remove oxidation and colour staining. You can use traditional polishing techniques (small working sections, higher speed, increased pressure) to remove extremely fine swirl marks, it is designed more of a paint cleanser; so apply using a finishing pad, slow speed and clean one panel at a time.

 Regular use of P21S® High Performance Total Auto Wash, a d-limonene (citrus) based cleaner or an all-in-one (AIO) type cleaner polish will ensure surface road dirt and grime is removed from the paint surface restoring the gloss to the paint surface. The 'yellowing' is paint oxidation caused by ultra violet (UV-A) radiation; it takes time and neglect of the paint for this to occur

Paint Hardness

The enamel paint finishes on vehicles from the 50’s and 60’s era were as tough as porcelain. But rightly due to environmental concerns, those high percentage petroleum based paints have been generally superseded, resulting in the softer water-based paint finishes of today and the unavoidable orange-peel seen on many new and re-painted vehicles.

Today’s paints, unfortunately, rank somewhere near the bottom of the scale of hardness, especially single coat black / red paint the exception being white single stage paint, which is 7 on a scale 1-10 and CeramiClear, when compared to all the materials your paint can possibly come in contact with (always bear that in mind).

Mohs scale of Hardness

A system of measurement to establish a guide as to the relative hardness of various materials, Mohs scale of mineral hardness was devised by the German mineralogist Frederich Mohs in 1812, selecting ten minerals because they were common or readily available. The scale is not a linear scale, but somewhat arbitrary.
The hardness of a material is measured against the scale by finding the hardest material that the given material can scratch, and/or the softest material that can scratch the given material. For example, if some material is scratched by apatite but not by fluorite, its hardness on Mohs scale is 4.5 (Not to be confused with Pencil Hardness, used to rate coating products)

An adaptation of that scale;
Talc =1, Carbon Black = 2, [black paint pigmentation] and Copper = 3, Platinum = 4, Iron = 5, Glass = 6, Quartz or Titanium dioxide = 7 [white paint pigmentation] and Topaz = 8, Corundum or Ruby = 9, Diamond =10

White paint is a 7/10 on the Mohs scale (Titanium dioxide) although hard and soft is a relative terms; you can scratch the hard surface of vehicles paint with a soft towel by the application of enough pressure. Both pressure and mechanical stress are defined as force per unit area. These two forces are the subject of Newton's third law of motion; the law of reciprocal actions [: to every action there is an equal and opposite reaction]

How can a hard clear coat be so easily scratched?
Force acts through a body that has a surface area; if the surface area is really small while maintaining an equal force, the pressure becomes astronomical and the object under pressure capable of penetrating the surface of an otherwise tough material. That’s why a micro fine thread that is twice as fine as silk and a 100 times finer than a human hair, in an otherwise soft towel will scratch your paint. And the same reason a mosquito can penetrate a rhino hide with its proboscis (stinger).

Pigment

Titanium dioxide, chemical formula TiO2, is the most widely used white pigment because of its brightness and very high refractive index (nD = 2.488 (anatase)), in which it is surpassed only by a few other materials. When deposited as a thin film, its refractive index and colour make it an excellent reflective optical coating TiO2 is also an effective opacifier in powder form, where it is employed as a pigment to provide whiteness and opacity to products such as paints, coatings, plastics, etc. In paint, it is often referred to offhandedly as the perfect white. Opacity is improved by optimal sizing of the titanium dioxide particles.
The exterior of the Saturn V rocket was painted with titanium dioxide; this later allowed astronomers to determine that J002E3 was the S-IVB stage from Apollo 12 and not an asteroid.


There are approximately 10-20 different colours that are mixed with white to produce various shades. The colour formula for white paint is a mix of yellow, blue, green, red, and black in various percentages to arrive at the required ‘tint’ colour (i.e. arctic white, brilliant white, etc) Ultra violet radiation sometimes places an emphasis on the yellow and creates a tarnished look, in a similar way a red paint turns to pink due to the red oxide content in the paints colour formula (this is more pronounced in older style paint like single pack acrylic or cellulose based paint rather than modern clear on base 2K pack paints

Surface Contaminants

White paint is subject to rail dust like every other paint colour; the only difference is that the rust stains show more readily than darker colours. 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.

Schedule: annually, dependent upon environmental conditions and vehicle exposure but more often on light coloured paint. To optimize the reflective properties and appearance of the paint surface, it is best to regularly remove both embedded and surface contaminants and road dirt and oils.

Rust Spots

They are usually caused by metallic brake dust that has penetrated the paint film surface and water / acid rain has produced rust. It can be removed with a decontamination product (ValuGuard) followed with a pre-wax polish/cleaner and a surface protection re-applied.

They should be removed as soon as it’s noticed as it may permeate under the paint surface, causing the paint to 'bubble' if this should happen the affected surface should be treated with a suitable rust inhibitor to avoid the rust contaminating other areas

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)

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 mark 
  •          Surface etching
  •           Oxidation
  •          Paint ‘stains
Light Reflective Value (LRV)


The average blackest black has a light reflection value (LRV) of approximately 5% and the whitest white is approximately 85%. Some yellows can measure up into the 80's or 90's as well. All colours fit in between these two extremes. A colour with an LRV of 50 will reflect 50% of the light that falls on it, and one with an LRV of 23 will reflect 23% of the light, and so on. Think of a reflective value as a numerical version of a grey value scale for colours, roughly like this-

Pure White - 100, White -95, Light - 80, Low Light - 65, Medium - 50, High Dark - 35, Dark – 20

Paint Care Product Suggestions

Paint cosmetic products that white and light colour paint respond well to after correct paint preparation -Aquartz System (Silica) Zaino Z2PRO™, Jeff Werkstatt, Opti-Seal topped with Optimum Car Wax Klasse SG (an acrylic polymer) and / or P21S Carnauba Paste Wax and Pinnicle Souveran wax

Table I Products for Light Paint Surface Colours

Silver

Klasse* All-In-One and

Menzera* Power Lock


White

Zaino * Z2PRO™ * Jeff Werkstatt, * Klasse SG, Duragloss 105 and/ or P21S Carnauba Paste Wax



Winter (Snow/Ice/Salt) Rain

Collinite #845 Liquid Insulator Wax, will last approximately 4-6 months


Strong Detergents / Chemicals

Collinite #845 Liquid Insulator Wax or #476s Super Doublecoat Auto Wax or * Duragloss 105



Acid Rain, IFO, etc

*Klasse AIO + SG * Duragloss 105

Note - * these products are synthetic polymers

Wax-the applications of Carnauba (Pinnacle Souverän™ Paste Wax) that will provide oils to provide a ‘wet-look’ to the surface and will also provide a transparent surface when layered without yellowing or discoloration, with a depth of shine by providing a two-dimensional surface.

Light coloured paint -i.e. Silver, White, etc (the exception is speed yellow) will never obtain jetting (the so called ‘wet-look’) of black or dark colours as they do not exhibit visible depth, light colours tends to reflect light instead of absorbing it and providing a 2-dimentional look.

You can obtain a good gloss provided the paint is good quality and if it’s prepared and detailed correctly; washed, cleaned, polished and a polymer sealant added (Zaino, Klasse AIO and SG, Jeff Werkstatt - Acrylic Jett ) these sealants will provide a flat silvery-white shine, but without ‘depth’ the exception is Zaino Clear Seal, Z-CS).

By adding a Carnauba wax or a Glaze as an LSP (Pinnacle Souverän™ Paste Wax or Autoglym Super Resin Polish or Danase Wet Glaze) the oils and / or polymers that are formulated in the Carnauba waxes provide a reflective gloss, which causes jetting (a ‘wetting’ of the surface) For optimal results the surface of a light coloured paint to show gloss is very much dependent upon good / excellent paint condition, adequately prepped to remove contaminants and minor imperfections.

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

Relevant TOGWT® Autopia Detailing Wiki Articles

  1. “Environmental Damage” - http://www.autopia.org/forum/car-detailing/136393-environmental-damage.html
  2. “Nanoskin Surface Prep Towel” - http://www.autopia.org/forum/autopia-detailing-wiki/141207-     nanoskin-surface-prep-towel.html
  3. “Paint Surface Cleaning prior to Polishing- http://www.autopia.org/forum/autopia-detailing-wiki/141354-paint-cleaning%3B-prior-polishing.html#post1502781
  4. Removing Rust Spots” - http://www.autopia.org/forum/autopia-detailing-wiki/141060-removing-rust-spots-rust-blooms.html
  5. ValuGard Paint Decontamination System” - http://www.autopia.org/forum/autopia-detailing-wiki/141242-valugard-paint-decontamination-system.html



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