Surface Tension

Surface Tension

The tension of the surface film of a liquid caused by the attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area

Surface Tension [: cohesive forces among liquid molecules are responsible for the phenomenon of surface tension. In the bulk of the liquid, each molecule is pulled equally in every direction by neighbouring liquid molecules, resulting in a net force of zero]

The molecules at the surface do not have the same molecules on all sides of them and therefore are pulled inwards. This creates some internal pressure and forces liquid surfaces to contract to the minimal area, which produces spheres of rain water (beading) on a waxy surface, such as a leaf. Water adheres weakly to wax and strongly to itself, so water clusters into drops. Surface tension gives them their near-spherical shape, because a sphere has the smallest possible surface area to volume ratio. Surface tension is responsible for the shape of liquid droplets or spheres. 

Although easily deformed, droplets of water tend to be pulled into a spherical shape by the imbalance in cohesive forces of the surface layer. In the absence of other forces, including gravity, drops of virtually all liquids would be approximately spherical. The spherical shape minimizes the necessary "wall tension" of the surface layer according to the Young–Laplace equation, describing pressure difference over an interface in fluid mechanics

Surface energy [: is the elastic tendency of liquids which makes them acquire the least surface area possible] 

It has the dimension of force per unit length, or of energy per unit area. Surface energy and surface tension are equivalents, but when referring to energy per unit of area, people use the term surface energy, which is a more general term in the sense that it applies also to solids and not just liquids. In order to successfully form a continuous coating, the liquid should be able to wet the surface of the material. 

Wettability depends on one specific property of the surface: surface energy. The surface energy of the solid substrate directly affects how well a liquid wets the surface. To achieve good wettability, the surface energy of the substrate needs to exceed that of the surface tension of the liquid by around 2 - 10 mN/m (Dynes). The Dyne level reflects the surface wettability - the higher the Dyne level, the better the wettability/adhesion.

“When is my paint past the point of no return; necessitating a vehicle repaint”

Polishing alleviates a myriad of paint surface problems. But use abrasive polishes wisely to maintain paint condition and to resolve surface damage problems. But know when to seek alternative methods of damage control and avoid over polishing with harsh, abrasive polishes.

Modern clear coat paint finishes are so good today that they lull people into thinking that vehicle paint has protection and shine when in reality there is not really much there, other than the clear coat that has a thickness of ~25.4 µ. As a point of reference a sheet of copy paper is 89 µ. 

The clear coat provides gloss plus physical protection from the elements, including ultraviolet (UV) radiation, which is in the upper level of a cured clear coat. Most car manufacturers will only allow ~ 25% of the clear-coat thickness to be removed without voiding the paint warranty and long-term durability problems becoming an issue. That means that if you started off with 50µ of clear coat (this will vary by vehicle mfg.) you would only be able to remove 12µ without voiding the paint warranty and possibly having a re-paint (Note: this may vary by vehicle mfg.).

There is ultra violet (UV) protection all the way through the paint, but the majority of it migrates to the top of cross-linked clear coat along with the thinner solvents and particles, the paint is also less dense (softer) below this level.  Therefore, removing clear coat ultra violet protection is not a linear process; by removing a small percentage of the clear coat paint tends to remove a larger percentage of the ultra violet (UV) inhibitors.

With a clear coat thickness of ~49µ and knowing that most of the ultra violet protection is in the top 50% (~24.5µ); therefore, limiting UV protection removal to   ~25 % means that approximately 6.125µ< can be removed before the ultra violet protection is compromised.  Once you remove too much clear coat you'll have no paint UV protection other than what you apply with a LSP (providing it contains UV protection.

Be cognizant that clear coat removal is not a liner process; and the first paint renovation will remove the most UV protection, therefore the above are probably conservative estimates. Two variables need to be established; how much clear coat is available and how much clear coat can be removed without compromising the paint systems long-term durability / paint warranty

·         200µ (micron) + can be expected on older cars that have been hand painted or a re-painted vehicle

·         100 – 200µ 4 – 8 mil - normal paint thickness

·         80 – 100 µ - 3 – 4 mils, thin paint

·         80 µ < - less than 3 mils, very thin paint

These numbers are offered as a guide only, as there are too many variables to provide any more than an approximation.

Ultra violet protection (UV) a clear coat paint (isocyanate polyurethane) provides the colour and base coats with protection, and usually has ultra violet (UV) protection added in the final coating; this tends to migrate towards the upper level of the clear coat (this is why it’s important to check how much of the paint surface you are removing with an abrasive polish)

Removing more than 0.5 mil (12µ) of clear coat will cause premature paint film failure UV protection is a sacrificial / renewable component; this is due to the UV protection layer being degraded by exposure to the elements (sun, sand, road or sea salt, and etc.) it is also water miscible, so it is imperative that you renew it and needs to be re-applied on a regular basis (dependent upon location climatic condition)

Alternatives to abrasive machine polishing

Swissvax Cleaner Fluid Professional Finish - its cut and gloss characteristics make it ideal for removing wash marring and faint swirl marks on all paint types, and its filler-free formula also makes it a great choice for refining out machine holograms after heavy compounding. Add to the equation the fact that it's easy to use, generates no dust and laughs in the face of sticky paint, and it's easy to see why it is a must-have product for minor enhancement duties on all modern Porsches and Range Rovers.

Swissvax Cleaner Fluid Regular - advanced chemical cleaning agents strip away any residual grime and old protective layers, while kaolin clay particles and heavy glazing oils visually reduce the extent of wash marring and minor swirl marks by filling such defects and robbing sunlight of sharp edges off of which to reflect. In short, Swissvax Cleaner Fluid Regular is a great product that effortlessly cleans and transforms the appearance of well-maintained paint in no time at all, which makes it ideal for enthusiasts and professionals alike.

Other Relevant Articles

1.      Clear Coat and UV Protection Removal- http://togwt1980.blogspot.co.uk/2015/05/clear-coat-and-uv-protection-removal.html

2.      The Physics of Polishing - http://togwt1980.blogspot.co.uk/2015/05/the-physics-of-polishing.html

3.      Basics of abrasive polishing - http://togwt1980.blogspot.co.uk/2015/08/basics-of-abrasive-polishing.html

4.      How to determine the least aggressive polishing method? - http://togwt1980.blogspot.co.uk/2015/08/how-to-determine-least-aggressive.html

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 above article was 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 this article as it helps other detailers further their knowledge.

Questions and/ or constructive comments are always appreciated.

Copyright © 2010 - 2016 TOGWT® (Established 1980) all rights reserve

Paint Surface - Light Reflection

Factors that affect Light Reflection

Reflection [: is either specular (mirror-like) or diffuse (retaining the energy, but losing the image)]

Surface type- reflectivity is a directional property; most surfaces can be divided into those that give specular reflection and those that give diffuse reflection. Most objects have some mixture of diffuse and specular reflective properties.

Refractive Index (RI) - by measuring the angle of incidence and angle of refraction of the light beam, the refractive index n can be determined. Refractive index of materials varies with the frequency of radiated light. 

Reflective Value (RV) - the reflective value of a colour indicates how much light and heat is reflected back from the colour surface.

 Light reflectance value (RV) is a numerical rating assigned by paint manufacturers to each colour they make. This number is a scientifically determined assessment of the amount light and heat that colour will reflect on a scale of 0 to 100.

Refractive Index (RI) or Haze Value -when light strikes the surface of a material it bounces off in all directions due to multiple reflections

Light Reflective Value (LRV) –the average blackest black has a light reflection value (LRV) of approximately 5% and the purest 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.

Distinctness of image (DOI) - the appearance of reflecting objects is determined by the way the surface reflects incident light. The reflective properties of the surface can be characterized by a closer look at the (micro)-topography of that surface.

Structures on the surface and the texture of the surface are determined by typical dimensions between some 10 mm and 0.1 mm (the detection limit of the human eye is at ~0.07 mm). Smaller structures and features of the surface cannot be directly detected by the unaided eye, but their effect becomes apparent in objects or images reflected in the surface. Structures at and below 0.1 mm reduce the DOI structures in the range of 0.01 mm induce haze and even smaller structures affect the gloss of the surface.

DOI meter measures the gloss and the distinctness of image (DOI) of a painted surface for quality evaluation of the finish. A signal is obtained by a prior method of focusing the reflected image of a moving shutter onto a slit and measuring the light passing through the slit. The rate of increase of the resulting signal is used as a measure of DOI. The same signal is integrated over a pre-set time period covering the upper part of the signal rise to yield a value proportional to gloss.

Calorimetric and colour theory - colourfulness, chroma, and saturation are related but distinct concepts referring to the perceived intensity of a specific colour.

As can be seen there are many factors to consider as to what constitutes optimum surface light reflection, one factor that has the most profound affect is light reflective value (LRV) or Surface colour 

Optimal Light Reflection

Requirements:

•         Clean-washed to remove oxidation, surface dirt and grime, tar and road film

•         Reflectivity – that comes from a clean and level surface

•         Gloss-that comes from oils and polymers with their ability to reflect light with a minimum of light diffusion to produce surface shine

•         Optical depth-comes from an applied product that is two-dimensional, so that light is reflected from both a high and low source, (i.e. a Carnauba waxes ‘egg-grate’ type structure) which ‘distorts’ reflected light to produce a rippling effect (warmth)as opposed to a polymer elongated and ‘chain-link’ type mesh, which exhibits a flat ‘mirror’ like shine

•         Optimising light refraction -apply product in ‘direction of airflow’, horizontal surfaces hood to trunk, vertical surfaces front to back. This application technique affects the paints optical properties by optimising light refraction and the reflectivity of the bodylines and contours of the vehicle

•         Transparency-or clarity of the applied product, which will enable all the above components to be clearly visible

Light Reflection

The way light is reflected from a paint surface affects the vehicles appearance after it is detailed.  Reflection of light is either Specular (mirror-like) or Diffuse (retaining the energy, but losing the image) depending on the nature of the surface. It is also possible for reflection to occur from the surface of transparent media, such as water or glass.

Transverse Waves - light is a form of wave motion, but as it travels at such a high speed it isn't possible to observe directly the way in which the moving waves vibrate. However, experiments show that the waves vibrate at right angles to the direction of the light beam, and because of this light is said to consist of transverse waves.

Laws of reflection- if the reflecting surface is very smooth, the reflection of light that occurs is called specular or regular reflection. The laws of reflection are as follows:

The incident ray -the reflected ray and the normal to the reflection surface at the point of the incidence lie in the same plane.

The angle - which the incident ray makes with the normal, is equal to the angle which the reflected ray makes to the same normal.

The way light is reflected from a paint surface affects the vehicles appearance after it is detailed.  Reflection of light is either Specular (mirror-like) or Diffuse (retaining the energy, but losing the image) depending on the nature of the surface. It is also possible for reflection to occur from the surface of transparent media, such as water or glass.

1.      Paint colours reflect light differently, i.e. a white or silver will reflect specular light. Darker colours i.e. red, black, etc. absorb light and therefore the reflected light is diffused.

2.      Metallic paint reflects light from the flakes, which create micro mirrors and add a distinctive ‘shine’  

3.      A polymer sealant or a nano coating product are more suited to the reflectance properties of light colours. An organic wax suit the reflective properties of darker colours due to its imparted jetting (the so-called wet-look)

Surface type

Reflectivity is a directional property; most surfaces can be divided into those that give specular reflection and those that give diffuse reflection. Most objects have some mixture of diffuse and specular reflective properties.

For specular surfaces- such as glass or polished metal, reflectivity will be nearly zero at all angles except at the appropriate reflected angle.

For diffuse surfaces - such as matte paint, reflectivity is uniform; radiation is reflected in all angles equally or near-equally. Such surfaces are said to be Lambertian.                                         

Spatial reflection – [: direction of incoming light (the incident ray), and the direction of outgoing light reflected (the reflected ray) make the same angle with respect to the surface normal, thus the angle of incidence equals the angle of reflection; this is commonly stated as θi = θr.]

The perfect, mirror-like reflection of light from a surface, in which light from a single incoming direction is reflected into a single outgoing direction the best example of spatial reflection is seen when reflected from a flat level surface.

If the surface is perfectly flat, light will be reflected to produce a mirror image of the surface. But if there you have matte paint or are imperfections such as swirls, surface contaminants, orange peel, or oxidation (dull, opaque or unlevelled paint) light is refracted and the reflected light becomes distorted, which mutes the shine.

        

Diffuse reflection [: incoming light is reflected in a broad range of directions] [1]

When light strikes the surface of a material it bounces off in all directions due to multiple reflections. The most familiar example of the distinction between specula and diffuse reflection would be glossy and matte paints.

While both exhibit a combination of specula and diffuse reflection, matte paints has a higher proportion of diffuse reflection and glossy paints have a greater proportion of specula reflection.

Refraction [: index of refraction n = c / v]

When we talk about the speed of light, we're usually talking about the speed of light in a vacuum, which is 3.00 x 108 m/s. When light travels through something else, such as glass, diamond, or plastic, it travels at a different speed. The speed of light in a given material is related to a quantity called the index of refraction, n, which is defined as the ratio of the speed of light in vacuum to the speed of light in the medium: index of refraction: n = c / v [1]

When light travels from one medium to another, the speed changes, as does the wavelength, the index of refraction can also be stated in terms of wavelength:  Although the speed changes and wavelength changes, the frequency of the light will be constant. The frequency, wavelength, and speed are related by Snell’s law: 

Refractive Index

By measuring the angle of incidence and angle of refraction of the light beam, the refractive index n can be determined. Refractive index of materials varies with the frequency of radiated light.

This results in a slightly different refractive index for each colour. The index of refraction characterizes not only the light propagation speed, but also the bending angle and the amount of radiation transmitted and reflected by a material 

Reflective Value

 [: a measurement commonly used in interior decorating and design, which expresses the percentage of light that is reflected from a surface] 

The reflective value (RV) of a colour indicates how much light and heat is reflected back from the colour surface. Light reflectance value (RV) is a numerical rating assigned by paint manufacturers to each colour they make. This number is a scientifically determined assessment of the amount light and heat that colour will reflect on a scale of 0 to 100. Zero assumed to be an absolute black and 100% being an assumed perfectly reflective white. An absolute black or perfectly reflecting white do not exist in our everyday terms.

Polymer sealant- comprises an open linked molecule, which forms a bond with the paint; these open linked polymer molecules join together to create an elongated mesh like effect that reflects light efficiently due to their inherent flat surface. Because they are usually very transparent they transmit the surface colour faithfully, but they have very little depth resulting in what is perceived as a very bright, but flat silver glow

A wax or sealant can only reflect what is underneath it, so a clean, level well-prepared surface is the most important consideration (85% of a surfaces reflectivity is due to its preparation) along with applied product clarity. If you apply a product over a surface that is dirty or one that has surface imperfections a wax or sealant will not hide or disguise (unless they contain fillers) but highlight them as the light will reflect differently from the rest of the paint surface.

Refractive Index

Refractive Index (RI) or Haze Value -when light strikes the surface of a material it bounces off in all directions due to multiple reflections. The most familiar example of the distinction between specula and diffuse reflection would be a polymer and a Carnauba wax.

While both exhibit a combination of specula and diffuse reflection, Carnauba wax has a higher proportion of diffuse reflection and Polymers have a greater proportion of specula reflection.

•         Mirror (specular) – RI: 1.00

•         Water - RI: 1.33.

•         Carnauba wax (diffuse) – RI: 1.45

•         Poly (Dimethalsiloxane) (specula) – RI: 1.48

The Angle of Rejection

When light reflects off of a surface such as a mirror, two angles are created from the light’s path and the surface of the mirror: the angle of incidence and the angle of reflection.

Light Reflective Value (LRV)

The average blackest black has a light (polarized) reflection value (LRV) of approximately 5% and the whitest white (un-polarized reflection) 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

It would take too long to list individual OEM colours, i.e. Arctic White, Speed Yellow, Guardsman Red, Onyx Black, etc. so you’ll need to interpolate

As can be seen there are many factors to consider apart from index numbers

Shine vs. Gloss

The reflective value (RV) of a colour indicates how much light is absorbed or diffusely scattered dependent on the colour.

·         High reflective value (i.e. white or very light colours) exhibit Spatial (Shine) reflection; a mirror-like reflection from a surface

·         Low reflective values (i.e. darker colours (black) exhibit a diffused (Gloss) reflection; incoming light is reflected in a broad range of directions

Backlighting

Clear coated paints show minor swirls and scratches more readily than pigmented paint (single stage) due to an optical effect called backlighting. Light penetrates the clear coat and is reflected from pigmented paint (colour coat) which in turn reflects any imperfections in the surface of the clear coat, making them highly visible. As you drive towards the setting sun or oncoming headlights on a rainy night, every speck of dirt, smudge or smear on your windshield is suddenly very obvious. They are much more noticeable when sunlight or oncoming headlights back-light them.

Light Coloured Surface

For secular surfaces, such as glass or polished metal, reflectivity will be nearly zero at all angles except at the appropriate reflected angle. For diffuse surfaces, such as matt white paint, reflectivity is uniform; radiation is reflected in all angles equally or near-equally. Such surfaces are said to be Lambertian. Most objects have some mixture of diffuse and secular reflective properties.

Reflection

Reflection and refraction are terms that describe how is reflected from a surface; refraction or diffused reflection) changes due to the microscopic irregularities of the surface, each medium has a different reflective value. As light travels and strikes the paint surface, it travels through the wax or sealant then the clear coat it reflects at different angles due to their differing reflective values.

 It will also reflect back at certain points where the angle of incidence equals the angle of reflection. As the photons of light gain proximity they become more brilliant. To enhance gloss you need to reflect as much light as possible, without interfering with that proximity or brilliance.

Proving the reflective surface is level, a rotary would produce a circular pattern, and a random orbital would produce an elliptical pattern, which would tend to separate the photons, thus reducing brilliance, while the circular would combine and concentrate them, thus enhancing gloss.

Gloss Meter

Intensity is dependent on the material and the angle of illumination. In case of non-metals (coatings, plastics) the amount of reflected light increases with the increase of the illumination angle. The remaining illuminated light penetrates the material and is absorbed or diffusely scattered dependent on the colour.

Gloss Measurement

A gloss meter is an instrument which is used to measure specular reflection gloss of a surface. Gloss is determined by projecting a beam of light at a fixed intensity and angle onto a surface and measuring the amount of reflected light at an equal but opposite angle.

Surface gloss [: is considered to be the amount of incident light that is reflected at the specular reflectance angle of the mean of that surface.]

Specular - means mirror-like and specular gloss is defined as the perception by an observer of the mirror-like appearance of a surface. In truth this appearance cannot be quantified: all that can be done instrumentally is to measure the amount of incident light that is reflected at a defined angle (or range of angles).

Measurement angle refers to the angle between the incident and reflected light. Three measurement angles (20°, 60°, and 85°) are specified to cover the majority of industrial coatings applications. The angle is selected based on the anticipated gloss range, as shown in the following table.

For example, if the measurement made at 60° is greater than 70 gloss units (GU) the measurement angle should be changed to 20° to optimise measurement accuracy. Three types of instruments are available on the market: 60° single angle instruments, a combination of 20° and 60° and one type that combines 20°, 60° and 85°.Materials with a higher refractive index can have a measurement value above 100 GU, e.g. films. In case of transparent materials, the measurement value can be increased due to multiple reflections in the bulk of the material. Due to the high reflection capabilities of metals values of up to 2000 GU can be reached.

Gloss - is a visual impression resulting from surface evaluation? The more direct light reflected, the more obvious the impression of gloss will be. Smooth and highly polished surfaces reflect images distinctly. The incident light is directly reflected on the surface, i.e. only in the main direction of reflection. The angle of incidence is equal to the angle of reflection.

Gloss units - the measurement scale, GU, of a gloss meter is a scaling based on a highly polished reference black glass standard with a defined refractive index having a specular reflectance of 100GU at the specified angle. This standard is used to establish an upper point calibration of 100 with the lower end point established at 0 on a perfectly matte surface. This scaling is suitable for most non-metallic coatings and materials (paints and plastics) as they generally fall within this range.

Two high gloss surfaces can measure identically with a standard gloss meter but can be visually very different. Instruments are available to quantify orange peel by measuring

Distinctness of Image (DOI) or Reflected Image Quality (RIQ) and Haze.

Rhopoint IQ Flex 20 is designed for the measurement of small and curved surfaces. This instrument quantifies surface quality problems such as orange and peel and haze that are invisible to a standard gloss meter and profiles how light is reflected from a surface.

Previously gloss meters were only available for measuring flat surfaces, this technology is now available in a new format specifically designed for curved surfaces and small & delicate parts.

Features:

·         Data Widget, which allows results to be instantly transmitted to any PC package such as Excel, Word, and SPC programs etc.

·         Bluetooth Compatibility that can transmit data to any smartphone, tablet or PC.

·         USB results download to PC without the need to install software

            

Reading shown:

Gloss: A measurement proportional to the amount of light reflected from a surface measured at 20° (high gloss)

Haze: (reflectance haze) an optical effect caused by microscopic textures or residue on a surface.

RIQ: Used to quantify effects such as orange peel and surface waviness. This new parameter gives higher resolution results compared to Distinctness of Image

DOI: A measure of how clearly a reflected image will appear in a reflective surface and better mimic’s human perception of surface texture, especially on high quality finishes such as automotive paint finish.

RSPEC: The peak gloss value over a very narrow angle.

Rhopoint IQ Flex 20 - http://www.rhopointinstruments.com/product/rhopoint-iq-flex-20/

Colour, Depth and Clarity - [: Reflectivity is the fraction of incident radiation reflected by a surface. In full generality it must be treated as a directional property that is a function of the reflected direction] 

Are the three factors Concours d’élégance judges look for when scrutinizing paint film surfaces. So much depends on proper surface preparation, a clean and level surface, and product clarity, which allow the natural properties of the paint to show through, as without transparency the true colours of the paint surface cannot be seen. Waxing a surface that has not been properly cleaned will only result in a shiny layer over dull, dirty paint - not the deep smooth, optically perfect crystalline shine that is obtainable

Gloss - is an optical property, which is based on the interaction of light with physical characteristics of a surface. It is actually the ability of a surface to reflect light into a specular direction. The factors that affect gloss are the refractive index of the material and the angle of incident lighting.

The oils that are formulated in Carnauba waxes provide gloss, which causes jetting (a ‘wetting’ of the surface) this distorts the light reflectance, giving the surface the ‘look’ of depth or liquidity (i.e. mirror in shallow water reflecting a three-dimensional deep, rich colour)

Depth – (iridescence) occurs due to the internal reflection of light within a transparent film or layer of material, where the thickness of the film or layer is of the order of the wavelength of the incident light. 

Where the wavelength of the light matches or is a low multiple of the path length through the layer it will re-emerge from the layer after a single reflection but where the wavelength is different to the path length it will be re-reflected within the layer until it emerges after several internal reflections. Changing your viewpoint changes the path length through the layer and this means that a different wavelength or colour of light will seem to be reflected.

Chromatics - the science of colour is sometimes called chromatics. It includes the perception of colour by the human eye and brain, the origin of colour in materials, colour theory in art, and the physics of electromagnetic radiation in the visible range (that is, what we commonly refer to simply as light).

Optical depth-comes from an applied product that is two-dimensional, so that light is reflected from both a high and low source, the light waves are distorted (diffuse reflection) which creates a three dimensional illusion of depth to produce jetting (a rippling effect, the so-called ‘wet-look)

The oils that are formulated in Carnauba waxes provide gloss, which causes jetting (a ‘wetting’ of the surface) this distorts the light reflectance, giving the surface the ‘look’ of rippling liquidity, like a mirror in shallow water reflecting a three-dimensional deep, rich colour, in contrast, bees wax, paraffin and many synthetic waxes and polymer sealants tend to occlude (cloud)

Shine – a perfectly ‘flat’ levelled surface is obtained by polishing the paint surface. Shine an easily understood concept of light reflection / refraction (in simple terms the light reflectance from a mirror) I wanted to expand that concept so that the shine would be optically perfect as well as multi-dimensional. The bright shine of a polymer sealant is often criticized as being “sterile” (a flat silvery-white reflection) good reflective properties but without ‘depth’ or jetting (wet-look) of an organic wax.

• Optimising light refraction - apply product in ‘direction of airflow’ to vertical surfaces roof to floor and then left to right, on horizontal surfaces bumper to trunk and then left to right, over-lapping panels to ensure complete coverage. Then apply in direction of airflow, horizontal surfaces hood to trunk, vertical surfaces front to back. This application technique affects the paints optical properties by optimising light refraction and the reflectivity of the bodylines and contours of the vehicle.
• The aesthetics- of a vehicles appearance is very subjective to say the least, the only best wax or sealant that really matters is what looks 'best' to you. In the final analysis it all comes down to; 85% preparation, 5% product, 7% application method and the balance is in the ‘guy’ of the beholder
• Optically Clarity – [: its refractive index (RI) allows a majority of the incidental light to be transmitted] 

      [The term ‘optical clarity’ is difficult to define, and the boundaries between ‘transparent’ or ‘clear’ and ‘translucent’ or ‘opaque’ are often highly subjective. What is acceptable for one observer is possibly not acceptable for another observer.] Zeus website

• An optically perfect shine comes from a clean, clear (i.e. the applied products do not occlude the surface underneath) prepared and level surface; it improves the desired optical properties i.e. surface reflectance. The other requirements are surface gloss, depth of shine and applied product transparency (clarity), which allows all of the components of an optically perfect shine to be visible.
• The best light reflection is obtained from a perfectly flat highly reflective surface, i.e. glass over a silver metallic material(a mirror)
• A polish would need to level a paint surface; this will provide a surface without distortion
• To provide protection to our theoretically perfectly distortion-free surface we would need to apply a wax or a polymer sealant, which in turn would need to be optically clear

Shine is an easily understood concept of light reflection / refraction (in simple terms the light reflectance from a mirror) I wanted to expand that concept so that the shine would be optically perfect (a majority of the incidental light is transmitted) as well as multi-dimensional. The bright shine of a polymer sealant is often criticized as being “sterile” (a flat silvery-white reflection) good reflective properties but without ‘depth’.

A clean polished paint surface will exhibit a bright shiny finish, which is great on light colour paint. On darker colours I prefer not just a bright shine but rather a deeper, darker gloss.

Similar to a car's black paint rippling as if it was under water. Carnauba in today's wax formulas functions as a carrier, it is used to keep the polymers and oils on your car's surface. Only a small portion of your vehicle's shine comes from the "wax" (i.e. carnauba) itself. Carnauba is translucent at best with only minimal light reflection.

The oils that are formulated in Carnauba waxes provide gloss, which causes jetting (a ‘wetting’ of the surface) this distorts the light reflectance, giving the surface the ‘look’ of a mirror in shallow water reflecting a three-dimensional deep, rich colour, in contrast, bees wax, paraffin and many synthetic waxes and some polymer sealants tend to occlude (cloud) the finish

The aesthetics- of a vehicles appearance is very subjective to say the least, the only paint protection finish that really matters is what looks 'best' to you. In the final analysis it all comes down to; 85% preparation, 5% product, 7% application method and the balance is in the ‘guy’ of the beholder

In obtaining the ‘optically perfect shine’ we should be equally concerned with ease of application, resistance to abrasion, atmospheric contamination and weathering. Products should be chosen that would carefully balance each of these considerations without focusing on one specific characteristic. A surface protection with a spectacular shine but limited durability just doesn’t make sense.

a) Requirements:

·         Clean-washed to remove oxidation, surface dirt and grime, tar and road film

·         Reflectivity – that comes from a clean and level surface

·         Gloss-that comes from oils and polymers with their ability to reflect light with a minimum of light diffusion to produce surface shine

·         Optimising light refraction -apply product in ‘direction of airflow’, horizontal surfaces hood to trunk, vertical surfaces front to back. This application technique affects the paints optical properties by optimising light refraction and the reflectivity of the bodylines and contours of the vehicle

·         Transparency-or clarity of the applied product, which will enable all the above components to be clearly visible

b) Contributing factors:

·         Cleaned- using a mildly alkaline (pH 7.5) car wash concentrates to remove surface road dirt and grime and then- using detailer’s clay to remove ingrained pollution from the paint surface, and a chemical paint cleaner (Klasse All-In-One) to prepare the surface for a polymer sealant and a Carnauba wax.

·         Polished-removal of minor blemishes, surface scratches, swirl marks and water marks with an abrasive machine polish or compound (Menzerna) to provide a level surface. A machine polish should remove surface imperfections and swirl marks, contain oils for lubrication and should not leave residue that requires extensive ‘clean-up’ to remove hazing, its solvents should evaporate moderately quickly without leaving excess wax/oils behind, and lastly should buff relatively easily.

·         Glazed- to obtain a high gloss by providing the necessary oils and burnishing the paint surface to a high optically clear gloss

·         Protected- the polymers carrier system (solvents) allows the product to fill and level the paint film surface to produce an ultra-flat surface while proving durable surface protection. A polymer (Zanio Z2PRO™) with its levels of shine, gloss, clarity, reflectivity, depth and 99% optical clarity, which doesn’t distort or detract from the paints colour or lines of the vehicle.

·         Waxed-the applications of Carnauba (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 or Klasse AIO and SG, Jeffswerkstatt - Acrylic Jett ) these sealants will provide a flat silvery-white shine, but without ‘depth’ the exception is Zaino  Clear Seal (Z-CS).

Bibliography

1.      Gloss as an aspect of the measurement of appearance by W Ji, MR Pointer, RM Luo, J Dakin

2.      Surface correlation effects on gloss by R Alexander-Katz, RG Barrera - Journal of Polymer Science

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