Sunday, 28 July 2013

Removal of Oxidized Paint

Oxidation [:  the loss of electrons or an increase in oxidation state by a molecule, atom, or ion]

Photo degradation [: decomposition of a compound by radiant energy] a common reaction is oxidation.

Cause

Ultra violet (UV) radiation exposure leads to gloss and colour instability (photo degradation or photo-oxidation) and surface fading stains. But before UV light can cause harm, it must first be absorbed. If it is not turned into heat or transferred to a nearby stabilizer molecule called a quencher, it breaks weak chemical bonds. This is the beginning of UV damage.

Some materials absorb UV radiation more readily than other materials. Materials that readily absorb (UV) radiation are quickly damaged...rubber, vinyl, gel coat fibreglass, and many other plastics.

When radiation is absorbed, it starts to break (cleave) weak chemical bonds, which leads to photochemical degradation (bleaching, (fading), discolouration, chalking, brittleness and cracking) all indications of UV deterioration. The bond cleavages resulting from UV absorption cause the formation of “radicals.” Each free radical can trigger a chain of reactions (in the presence of air), leading to more bond cleavages and destruction. These oxidising chain reactions require no further UV exposure, just the presence of air

Today’s water-based products have a number of obvious environmental benefits, but some are more susceptible to photo degradation (fading) over time, a significant drawback. In addition, because of ozone depletion, higher levels of solar ultra violet (UV) radiation now reach the surface of the earth. This further contributes to the rate of fading.

Polymers use in auto paint, plastics and vinyl, where they are routinely exposed to sunlight; the UV radiation adversely the mechanical properties of these materials, often causing structural failure, which limits their useful life.

Photo-oxidation of polymers

Photo-oxidation (sometimes incorrectly described as oxidation) is the degradation of a polymer surface in the presence of ozone. This is a consequence of ultra violet (UV) radiation, which instigates a chemical change that reduces the polymer's molecular weight. As a consequence of this change the material becomes more brittle, with a reduction in its tensile, impact and elongation strength. Discolouration and loss of surface smoothness accompany photo-oxidation. Infra red (IR) radiation or high surface temperature significantly increases the effect of photo-oxidation by drying.


Clear Coat Oxidation - Failure

Effect
Acids enter the breach formed in the clear coat and attack the resin binder system, which accelerates the degrading of the paint film surface, eventually leading to oxidation and/or failure.

Ultra violet (UV) radiation is known to contribute to the chemical modification (oxidation) or drying out the polymers and the resin binder system of exposed paint surfaces resulting in loss of gloss. However (clear coat failure) results in colour change, chalking, flaking and eventually destruction of the paint film

Oxidation can appear as a dull and somewhat hazy, or `chalky' appearance to the paint surface, a paint film surface that is adequately protected with wax or a sealant actually has a lower surface temperature than one that is not.
A dark coloured vehicle parked in the sun can attain a surface temperature in excess of 200° F With both types of paint system the application of a Carnauba wax provides a sacrificial and easily renewable barrier against airborne contaminants, which means the wax is compromised not the paint system

The clear coat layer is extremely thin (1.5 – 2.0 Mils) it is not a solid coating and is to some extent porous, the top most layer of clear coat paint contains ultra violet (UV) protection. Oxygen interacts with substances in the paint layer (i.e. mica flakes as in metallic paints) and trigger the oxidation reaction. It's just that the amount of oxidation taking place is minimal in comparison to single stage paint.

Paint oxidation

An automobile with an oxidized clear coat paint finish can be restored up to the point that clear coat failure begins (blotchy white / gray areas).Paint oxidation is the result of ultra violet (UV) radiation drying out the polymers and its resin binder system of exposed paint surfaces resulting in loss of gloss (clear coat failure) colour change, chalking, flaking and eventually destruction of the paint film

Removing oxidation necessitates thinning the clear coat, and therefore successful paint renovation will be dependent upon how much paint thickness there is. Sometimes a non-invasive chemical paint cleaner like Werkstat Prime Strong, a water-based cleaner for removing contaminants from paint surface maybe all that is necessary

Ultra violet (UV) protection is 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. Take measurements with a paint thickness gauge (PTG) or take the vehicle to a body shop and have the paint thickness measured. If the car has sufficient paint thickness you should be able to make it look very good with the right polishes

                  Two stage paint system- (base, colour and clear coat) - a clear-coat finish does not oxidize in the true sense of the word (meaning that the pigments and resins mix together and the pigments are exposed to the sun's ultra-violet rays, which causes them to dry out or oxidize. The clear coat is applied to protect against this but the finish will become ‘dull’ by using harsh (abrasive) or if acidic car washing solutions as used in ‘touch less’ car washing systems, or from industrial airborne pollutants compromising the clear coat allowing the suns heat to dry out (oxidize) the paint.

·         Wash the paint surface and dry thoroughly
·         Clean the paint with chemical paint cleaner (Werkstat Prime Strong,  Autoglym Paint Renovator or Klasse All-In-One) using an orange foam pad at speed #4, this may take 2-3 applications
·         Apply a paint surface protection

          Single stage paint systems (base and colour coat) – without a clear coat to provide protection, primarily a hostile environment will attack the paint surface causing microscopic gaps and valleys (micro fissures) and it becomes compromised both chemically; by industrial fallout (IFO) acid rain, brake /rail dust and etc., and by ultra violet (UV) heat radiation, which causes it to dry out and/or fail, further causing the clear coat to expand and often separate from the base coat, allowing environmental pollutants to penetrate.

 Single stage is easier to correct than most clear coats, as a general rule use a more aggressive pad before moving up the scale in an abrasive polish.

Optimum's Hyper Polish and / or Hyper Compound used with a Microfiber pads are very effective at removing oxidation from single stage paint

      For highly oxidized paint systems (or Nitrocellulose lacquer)
·         Wash the paint surface and dry thoroughly
·         Clean the paint with chemical paint cleaner (Werkstat Prime Strong)  using an orange foam pad at speed #4, this may take 2-3 or more applications
·         If you need a more abrasive polish; use a high speed rotary and try Optimum Hyper or Menzerna  Power Gloss with a LC White polishing foam pad, if  the results are not satisfactory then step up by to  going to a LC Orange (light) cutting foam and then if needed a LC Yellow cutting foam pad.
·         Once the oxidation has been removed use a decontamination system (C.Quartz IronX)
·         Apply an oil rich product to stabilize the paints binder system (3M Imperial Hand Glaze) apply a thick coat and allow to dwell time for 12-24 hours before buffing, repeat as necessary until surface has an ‘oily’ sheen.
·         Remove residue with 1:10 solution of isopropyl alcohol and distilled water

Finally apply a coating (Opti-Coat™) a pre-polymer that cross links and forms a semi-permanent continuous film on the surfaces it is applied to similar to a single component Isocyanate that forms a clear coating finish.

Relevant Articles

1. “Clear Coat Thickness and UV Protection Removed by Polishing” - http://www.autopia.org/forum/car-detailing/136818-clear-coat-uv-protection-removal.html#

2. “Environmental Damage” - http://www.autopia.org/forum/car-detailing/136393-environmental-damage.html#

3. “Nanoskin Surface Prep Towel” - http://www.autopia.org/forum/autopia-detailing-wiki/141207-nanoskin-surface-prep-towel.html

4. “Oxidation or Clear Coat Failure?” - http://www.autopia.org/forum/autopia-detailing-wiki/141208-oxidation-clear-coat-failure.html

5. “Paint Thickness Gauge (PTG)” - http://www.autopia.org/forum/guide-detailing/137139-paint-thickness-gauge-ptg.html#post1454624

6. UV Radiation Damage – http://www.autopia.org/forum/guide-detailing/136963-ultra-violet-uv-radiation-damage.html?daysprune=100







Saturday, 27 July 2013

Headlight Restoration

Polycarbonate lenses before & after

Modern automotive lenses are made of high impact thermoplastic based acrylic / polycarbonate, this allows for headlight designs in a variety of shapes and sizes, making their configuration, one of the most diverse in automotive design history.

This material is versatile and beautiful, but it has a limited life expectancy. Unlike Glass which would last virtually forever, climate and environmental contamination has a negative impact on their appearance.

Cause

Over the years, the polycarbonate headlight lens on any vehicle are subjected to heat and humidity - high Intensity discharge (HID) bulbs also bulbs also contribute to the deterioration of the polycarbonate lens as they emit heat from inside the lens, heat from the engine bay, radiation heat and humidity from the atmosphere, depending on climate and season

Other environmental contaminates can have a negative impact, they rapidly succumb to photo degeneration and oxidation caused by ultra violet (UV) radiation and the lens becomes hazy and yellow and when exposed to environmental contaminants like salt air, acid rain and excessively harsh (alkaline) cleaning chemicals.  Road salt is also a yellowing agent, and then there is the effect of high-speed collision abrasion from dust, road grit and insects.

Effect
All of the above will cause the lens to become oxidized (opaque) causing lack of available road illumination. Hazy headlights aren't just a cosmetic issue; they’re a safety issue, too and replacing headlights can get extremely expensive, and is often unnecessary.

Remedy
Because the damage on the lenses is usually purely superficial, they can be restored to an as-new clarity with minimum time and effort with the headlights still on the vehicle. If the lights are pitted, they will have to be sanded. But if they are just dull, hazy and yellow, surface polishing with a chemical paint cleaner (Werkstat Prime Strong). This formula takes a step toward a finishing polish and can eliminate the need for a more aggressive polishing in many instances.

This product contain  mild abrasive so will help to remove oxidation, light swirl marks and scratches, used with the right pad (LC White light polishing foam pad,  orbital speed #3 - 4)

What condition are your headlights in?
1.      Do your lenses appear to have a thin layer of plastic wearing off the lens?
2.      Is the lens deeply pitted?
3.      Are there scratches visible on the surface of the lens?
4.      Does the lens appear to have thousands of tiny micro fractures in it?

The above conditions go beyond the effect of natural oxidation. Dependent upon the extent of the damage it can sometimes be restored by resurfacing utilizing wet-sanding and/or polishing systems.

Headlight Kits

Be cognizant that some ‘headlight restoration kits’ use fillers (Kaolin or Dimescous Earth) to ‘mask’ as opposed to an abrasive that will remove lens surface problems.

3M Headlight Restoration Kit (136050) - a complete headlight restoration; from scratch removal to sealant; the kit contains a sealant that requires ultra violet curing (UV lamp or in sunlight, 10-15 minutes) aerosol spray hard coat to protect the restoration. Ford Motor Company has tested and approved their sealant in their Weatherometer in Detroit exhibiting a durability of 3 years minimum.  This is currently the only OEM tested and approval product of this type that meets standard ASE J2527 paint testing protocols.

Lexan® Polycarbonate

In the late 1980’s, vehicle manufacturers changed the lighting lens system materials used for head lights from glass to a polycarbonate. Original equipment manufacturers (OEM) needed a material that could be moulded to aerodynamic shapes and was lightweight. A polymer material, Lexan® Polycarbonate, which was both lightweight and could be moulded into many different shapes aerodynamic shapes, making it suitable for sports cars.

Is a registered trademark of SABIC Innovative Plastics; a highly durable polycarbonate resin thermoplastic intended to replace traditional glass and Plexiglas where the need for strength and impact resistance justifies its higher cost.

Vehicle Head Lights

To the naked eye one cannot tell that these plastic lenses are actually a porous material that expands ever so slightly when it gets hot. Degradation of the lens occurs over time Having your headlights on or being exposed to the heat of the day causes expansion of the micro-the pores, allowing debris from the road to get in.

Headlights are usually made from Polycarbonate; it has its advantages (light weight, easily formed to differing aerodynamic shapes, etc) but also has its disadvantages; namely oxidation / discolouration or more correctly photo degradation

Tail light, turning and signal (turn indicators) are usually made from heat and impact resistant acrylonitrile butadiene styrene (ABS)

Oxidation (photo degradation) - of the polycarbonate headlight causes it to dry out the plasticizers and become cloudy or take on a yellowish tinge. Ultraviolet (UV) rays from the sun also cause the lens to develop micro-cracks, hastening the colour change. If the lights are pitted, they will have to be sanded. But if they are just dull, hazy and yellow, surface polishing will restore clarity. This debris can be removed with a chemical paint cleaner (Klasse AIO or Werkstat Prime Strong)

Surface damage - when the lens starts to exhibit an opaque appearance and then a yellow hue on the outside of the lenses, this is due to ultra violet radiation (UV), which also causes micro-cracks. Road grit / debris and harsh chemicals cause surface scratches. This can severely restrict the amount of light reaching the road and this becomes a safety issue as you rely on the vehicles lighting system to see what’s on the road ahead and adjust your driving accordingly.

1.      Wash and thoroughly dry the lenses
2.      Tape-off all around the lenses so that you don't accidentally wet sand or buff the surrounding areas.
3.      Use a Nanoskin surface prep towel to remove any surface contaminants
4.      Using a random orbital buffer with a 3.5-inch backing plate and a 4-inch (Lake Country (LC) Mfg) White polishing pad or a terry cloth applicator
5.      Place a small dab (about ½-inch diameter) of plastic polish on the foam pad or applicator.
6.      Place the pad on the lens surface and turn on the machine (speed #4)
7.      Polish the lens repeatedly in a left-to-right and an up and down pattern.
8.      Continue polishing until all the polish is gone
9.      Wipe the lens with a damp Microfiber towel
10.  Inspect the lens; repeat the polishing process 2-3 times as necessary
11.  Finally wipe down the headlight surfaces with isopropyl alcohol (IPA) or a tack rag to eliminate any residue.

Notes –
1.      Polishing or wet-sanding  will not remove clarity defects that are within the plastic but it will remove external/surface scratching and ultra violet (UV) oxidation (yellowing) as well as OEM applied UV protection that should be replaced
2.      Softer polycarbonate resists breakage but will oxidize faster.
3.       Don’t use abrasive or highly alkaline cleaners.
4.      Never scrape the sheet with squeegees, razor blades or other sharp instruments.
5.      Don’t clean Lexan® Polycarbonate products in the hot sun or at elevated temperatures as this can lead to staining?

Original equipment material (OEM) suppliers started to add ultra violet resistant (UV) coating to the surface of the lens in an attempt to reduce this condition and prolong the usable life of the lens. This protective coating is very thin (25 µ (microns or 1 Mil)

Removing oxidation or scratches from vehicle headlights or brake lights (also polycarbonate) also removes the OEM ultra violet protection, which prematurely decreases the durability of the lens. Surfaces that have yellowed are a sign that the ultra violet (UV) sacrificial coating has failed and must be resurfaced and recoated.

Ultra Violet Protection - polishing or wet-sanding headlights without renewing their ultra violet (UV) protection is a false economy, unless this protection is replaced, the end result is that you'll have to do them again in a few months (repeat this polishing process enough and there will be no material left to work with)

Preventive Measures

There’s nothing you can do to stop plastic from degrading, but you can certainly slow the process down, however, by avoiding salted roads and prolonged sun exposure whenever feasible.
Cleaning the lenses on a regular basis (whenever you wash the vehicle) and using a mild , polycarbonate compatible polish on a semi-regular basis, and some companies even offer clear protective films that provide a buffer between your lenses and the elements. Such measures do more than just promote safety; they‘ll also improve the resale value.

Optimum Opti-Lens™


In order to restore the lens back to its OEM standards a new ultra violet (UV) resistant coating must be re-applied. For brand new vehicles, Optimum Opti-Lens™ is formulated with an acrylic and various co-polymer resins designed to cross-link with polycarbonate and will adhere to the factory-applied film to increase its life span. Or on refinished headlights, where the coating has failed and has been removed do to polishing.

Optimum Opti-Lens Headlight Coating - an advanced, resin-based coating Opti-Lens is a hybrid coating based on Opti Coat. OPT added acrylic for flexibility due to the constant expanding and contracting and increased the ultra violet (UV) absorber content to accommodate the absence of protection inherit to polycarbonate. This product is specifically designed to provide protection for OEM headlights, taillights and other poly-carbonate surfaces

Apply directly to the headlight using a poly foam applicator or Optimum Dual Pro Applicator. Work a small amount of product over the lens using overlapping passes until it appears to melt into the lens and disappear. Remove any streaks or high spots with a soft microfiber towel. It takes approximately 30 minutes to cure before it can be exposed to water. Allow 24 hours to pass before washing or cleaning with pressure.

This product can only be removed via mechanical means (abrasive polishing) it does not wear off.

·         Apply a thin coat side to side, which will leave a trail behind the applicator and then top to bottom seeing a trail behind the applicator.
·         When 80% of the area has flashed to clear (rainbow colours disappeared), lightly buff off any remaining product with a micro fibre.
·         Don’t buff unnecessarily during application or when removing excess. It’s easy enough to remove a dried high spot by hand and it’s better to remove them after it cures

.Alternate Product

G|Techniq C4 is a permanent headlight sealant; it has a durability of ~ two years (dependent upon conditions encountered).

Headlight (Physical) Protection

Even after a headlight restoration project prevention is always better than a cure; with the average cost of replacement head lamps and fog lamps spiraling to nearly $300, it is nice to know that there is a product available to protect your car against the perils of the open road. These products are made from a proprietary, scratch-resistant, urethane material coupled with the strongest optically clear adhesive available

a)      Protect your expensive headlamps, before it's too late. WeatherTech® LampGard™ uses a tough 40 mil thick, double-polished urethane material that is optically clear and applies (peel & stick) directly to the surface. This product has built-in ultraviolet inhibitors that help prevent the material from drying, hardening or discolouring. Custom die-cut to fit your specific vehicle for a precise, perfect fit, it comes with easy-to-follow instructions and applies to headlamps, fog lamps, turn indicators and parking lights (when applicable) to protect them from scratching, cracking and pitting.

b)      XPEL™ Designed for maximum durability, these light covers were originally tested under the harshest of circumstances with amazing results. Both in the real world and in the lab, these covers have proven that they will withstand a barrage of 1" diameter stones (about 1oz.) at speeds up to 120 M.P.H. with no damage to the lens they protect. It is nice to know that your expensive lenses are protected in every scenario. We are so confident in our product that we offer a 5-year warranty to leave you with complete peace of mind. Headlight protection film can also improve the look of old headlights by reducing the haze build-up

Relevant Articles




Friday, 26 July 2013

Paint surface, depth, warmth, gloss, etc.


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, likened to 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) An optically perfect crystalline shine is the result of combining a polymer sealant for its reflective shine properties with a Carnaubas three-dimensional jetting properties.

Clean surface – both above and below surface contaminants have been removed and a chemical paint surface cleaner has been used to remove ‘ingrained dirt

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). Unless the paint surface is cleaned and properly levelled the surface will not have ‘shine’ (its ability to reflex light) and the other attributes (Colour, Depth and Clarity) are meaningless

Colour, Depth and Clarity- 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 gloss 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.

Some products will maximise metallic flake, others reflectivity, or depth of shine and colour richness (wetting, also known as jetting). Factors such as durability are objective and are an easily quantifiable part in the process.

There is no one product that can produce all of the properties for an optically perfect shine, however; for high surface gloss and surface reflectance-a polymer sealant, which also provides durability. Detailing enthusiasts consider shine as only one attribute of a protective wax or sealant. They are equally concerned with; ease of application, resistance to abrasion, atmospheric contamination and weathering as well as strong cosmetic enhancement characteristics

The final result can only be as good as the surface it’s applied to. It really is all dependants upon, process over product; 85% surface preparation, 5% product suitability, 7% application methodology and the balance is in the ‘guy’ of the beholder. The other variables are; a detailer’s knowledge of the paint type, experience with a given product and skill level and experience with machine polisher.

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...

Friday, 12 July 2013

Leather Conditioning


Section through finished leather


Leather Hides

Raw hides have four main parts - an epidermis, grain, corium and flesh
Two of these layers, the epidermis (which is a thin protective layer of cells during the life of an animal) and the flesh are removed during tanning by a process called liming.

This leaves just the grain and the corium, the parts that are used for automotive leather upholstery .The grain layer is made of collagen and elastin protein fibres and its structure varies quite a bit depending on the age, breed and lifestyle of the animal. The grain carries many distinctive marks such as insect bites, growth marks and wound scars giving the leather a unique appearance.

A simple test – place a drop of moisture on the surface of the leather - if it soaks into the leather you have unfinished leather (sometimes called aniline style) If there is a very light colour or clear coat on top of aniline-dyed leather, it is often referred to as “semi-aniline.” Semi-aniline leather offers modest protection while retaining much of the aesthetic beauty of unfinished aniline-dyed leather but still remain absorbent to moisture. If the moisture sits on the surface and does not soak in and darken the material you have finished leather.

The corium [Latin term for the dermis] or skin layer, is packed with collagen protein fibres, arranged in larger bundles and interwoven to give the structure great strength, excellent elasticity and durability. In the tanning process these fibres and impregnated with collagen's that are designed to hold them together and keep them supple after which they are sealed, these polymers are neither volatile nor migratory, rendering the use oil-based conditioner a mute point

The other critical factor is moisture (re-hydration) any leather is going to lose its moisture in hot ambient environments.  Much of the suppleness of leather comes from its moisture content, which is the reason maintain the moisture content of the corium is so important. When leather tanners talk about leather conditioning they specifically mean replacing its moisture content (re-hydration).  After tanning the skin is protected with a thin pigmented (colour) urethane and then a clear topcoat.

Urethane has micro-pores that allow evaporation and hydration (the passage of water vapour through a membrane or pore) they are not sealed per se. Oils are not compatible with water-based pigmented urethane coatings and their molecules are too large to permeate, although some may enter via stitching, usually it remains on the surface to be removed by clothing

Since the leather hide has a pigmented urethane layer and clear topcoat finish, when treating the leather, so you are in fact dealing with a urethane (to all intents and purposes, a ~150 µ (micron) thick plastic surface coating, about the same thickness as automobile clear coat paint; that simply needs to be kept clean and hydrated…it really is that simple.

Before 1980 most automotive leather upholstery used was high quality top grain full grain leather with a pigmented solvent-based Nitrocellulose lacquer coating and their unstable plasticizers would easily migrate in the heat from sun exposure and again create 'fogging' on the internal surfaces of the windows.
As a result of this plasticizer migration the use of oil-based products that contained solvents to keep them from becoming brittle and cracking, creams, waxes and oils were needed in after-care products to try and bring the suppleness back into the leather by applying an oil-based conditioner; a term that became known as ‘feeding ‘

Automotive leather has a pigmented urethane clear coat to add colour and a clear top coat to provide abrasion resistance and protection from the harsh environment of the vehicles interior 

Two stage paint; base (colour) coat and clear coat were adopted (around 1982) as an automotive industry standard to replace these older lacquer paints. There is a minor difference between vehicle and leather clear coats, clear coat paint or resin has no pigments and hence imparts no colour to the vehicle. It’s simply a layer of clear resin that is applied over coloured resin. 

Whereas finished leather’s clear coat has pigmentation added to provide colour. Almost 95 percent of all vehicles manufactured today have a clear coat finish, the new clear coat urethane paint did not require oils but the old method of feeding paint took many years to fade out.

This same resistance to change also applies to finished leather even though urethane’s only requirement is to be kept clean and hydrated, it doesn't require conditioning

It’s possible that there is an association with old world quality (i.e. European automobiles with unfinished leather upholstery and real burl wood interiors) with these types of products, despite the fact that the automotive industry has been using aqueous (water- based) urethane covered pigmented leather since 1980.
Something else that always surprises me is that many detailers aren't old enough to remember Nitrocellulose lacquer coating, yet they are adamant that conditioning is a prerequisite for finished leather


I hope you've found this article both informative and helpful.

TOGWT® Autopia Detailing Wiki Articles
  1.  Unfinished leather” - http://www.autopia.org/forum/autopia-detailing-wiki/145381-unfinished-eather.html#post1543547
  2. "Proper  Finished Leather Cleaning and Care” - http://www.autopia.org/forum/guide-detailing/136421-proper-finished-leather-cleaning-care.html
  3.  “Leather Upholstery Type Surface Identification” - http://www.autopia.org/forum/autopia-detailing-wiki/136895-leather-upholstery;-surface-identification.html#
  4. “Leather Articles Hyperlinks” -http://www.autopia.org/forum/autopia-detailing-wiki/141973-leather-articles-hyperlinks.html



Wednesday, 10 July 2013

Wipe down Process

The wipe down process should be carried out both before to ensure a surface that is free of any debris and after to ensure that defects have been removed as opposed to masked by any lubrication oils or fillers left behind after the polishing process. The wipe-down process may need to be repeated to ensure a perfectly ‘clean’, debris free surface

Wiping the finish with a micro fibre cloth you may feel that the swirls have been removed, only to have them reappear after the surface has been washed. After polishing a section, mist and wipe to fully remove residues and reveal the true paint finish. Nothing worse than a client having paid for paint renovation to wash the paint surface and then have paint marring reappear

·         Polymer sealants will not form a proper monocular bond with a paint surface if there are any silicone or synthetic oils present, they will also negatively affect durability if not removed

·         Silicone will cause surface smearing and will affect abrasives effectiveness, product  bonding and durability (See also Silicone Removal

Water-based polishes tend to fill far less than oil-based; but they both contain silicone resins and polymer or wax lubricants. A wipe down after polishing or compounding is used to remove the carrier oils and wax used for surface lubrication and allows you to inspect the surface to determine if the surface is defect free or if further work is required.

When polishing or compounding to remove fine swirls or holograms, it's easy for residues and / or waxes or oils to settle in the swirls, hiding the true paint finish (drop back).

Prior to the application of a paint protection coating it is absolutely necessary to remove any (mostly invisible to the naked eye) fillers and oils; if they are allowed to remain a white or grey hazing will appear on the paint once the coating is applied.

It’s the one thing that keeps those who practice paint correction honest. Paint enhancement (glaze or an oil-based wax) anybody can do. But paint correction is a lot harder and IPA (or equivalent) is a liquid lie detector

Evaporation [: vaporization of a liquid that occurs from the surface of a liquid into a gaseous phase]

Isopropyl alcohol

[Anhydrous Isopropyl alcohol [Molecular formula C3H8O] for all-purpose cleaning, isopropyl alcohol, is a colourless liquid with a pleasant odour, and is highly flammable. A miscible clear fluid, Flash point 53.0F (12.0C) closed cup]

Reagent isopropanol alcohol, whether a technical, surgical or analytical grade will be X % isopropanol alcohol, the remaining percentage will be made up with water and is available as a 70 to 95 percent % solution.

The term "rubbing alcohol" has become a general non-specific term for either isopropyl alcohol (isopropanol) or ethyl alcohol (ethanol) Rubbing-alcohol products can leave a residue behind It is prepared from a special denatured alcohol solution and contains 97.5-100% by volume of pure, concentrated ethanol (ethyl alcohol) or reagent isopropyl alcohol (IPA)

Be cognizant that modern paint systems are porous, so be cautious as to what solvents you use. Dependent upon the particulate size, some chemicals penetrate easily, only liquids that are smaller on a molecular level than the cross-linked paint can be absorbed; solvents and alcohol can permeate the paint causing the paint to temporarily swell hiding surface scratches and marring

Reagent isopropyl alcohol (IPA) and or other solvents will permeate the paint, causing both temporary softening and some swelling. Depending on the solvent (strength) used and the amount of ambient heat, the amount of swelling varies. (See also “Paint (Solvent / Alcohol) Swelling”)

 Using undiluted reagent isopropyl alcohol, even 70% IPA can soften the paint excessively, but as you increase the dilution, the softening drops exponentially, this softening effect is temporary. Using an abrasive polish on solvent softened or ‘swollen’ paint may cause the paint film to wrinkle or delaminate (tear or separate)

For less dense (soft) clear coat, the lower rate of dilution (1:10) is recommended; conversely denser (dense) clear coat should use a higher dilution (1:25); as you increase the dilution rate of reagent isopropyl alcohol its paint softening effect drops exponentially. The reason for this wide range is due to the variations in clear coat paint systems

Isopropyl alcohol (IPA is a fast evaporating solvent, which usually fully evaporate at temperatures above 80.OF , whereas , slower evaporating solvents like mineral spirits  may take several days before they reach levels below 1%.
Reagent isopropyl alcohol (IPA) is readily available and like acetone, it dissolves a wide range of non-polar compounds. It is also relatively non-toxic and evaporates quickly. Thus it is used widely as a solvent and as a cleaning fluid [1]

Mineral oil can be used to clean heavier oil stains by diluting and liquefying the other oils, rendering the oils more accessible to detergents. Likewise, it can be employed to de-gum, to remove adhesive residue left by adhesive tape. Be cognizant that while it can be used as a solvent cleaner it can leave a residue, which is undesirable for paint cleaning applications.

Denatured alcohol (or Methylated spirits) - is ethanol that has additives to make it more poisonous or unpalatable, and thus, undrinkable. Do not use denatured alcohol as a substitute for reagent isopropyl alcohol (IPA)

Use caution if using paint thinner / strong solvent as there is a possibility that it can have detrimental long term effects, which cause the paint matrix to fail over time leaving a dull area that has a similar appearance to strikethrough, which cannot be corrected


Distilled water

Potable water usually contains a number of microscopic contaminants (turbidity) along with dissolved minerals such as calcium and iron. Distilled water should ideally be nothing but hydrogen and oxygen molecules and virtually all of its impurities are removed through distillation, which involves boiling the water and re-condensing the steam into a clean container (pH 6.0 – 7.5)

Any dissolved solids such as salt, bacteria, calcium or iron remain solid while the pure water converts to a much lighter steam and is drawn out for condensation, leaving most if not all solid contaminants behind. Distilled water is preferred for dilution as it’s a ‘known’ quality, unlike domestic potable water

In larger chemical and biological laboratories, as well as industry, cheaper alternatives such as deionised water are preferred over distilled water.

Wipe down Application Process

Application - fill a fine misting spray bottle with a dilute solution of reagent isopropyl alcohol (IPA) / distilled water Spray the surface you have just polished and allow the solution sit for approximately 15 seconds. If it flashes too quickly (hot surface or environment) use further dilution

Reagent isopropyl alcohol (IPA) and or other solvents will suspend waxes and silicones, and then re-depositing them, this can be avoided by adding 10% d-limonene (P21S Total Auto Wash) to the dilute IPA solution and wiping the surface with a clean, dry micro fibre towel.  (TAW will provide surface lubrication to minimise surface marring on less dense (softer) paints)

Agitate the area with a clean panel wipe or a  soft 100% cotton micro fibre towel (you may need to repeat this process) change the towel to a fresh quarter after each panel to ensure oil and debris are not re-deposited and observe.

This should have removed any wax or oils that may have filled any remaining swirls and show the true post-polish surface condition.

If a diluted IPA solution doesn’t remove the surface oils perhaps a specific paint preparation product, i.e.  CarPro Intense Oil & Polish Cleanser or DuPont PrepSol II™ may be more suitable

Now using your surface inspection light, shine the light directly on the panel and look for fine swirls. If they are still present, you should be able to see them. If not you will see a clear bright reflection from the panel with a great shine, and clarity

These fast acting solvent cleaners will not leave a film residue
·         CarPro Intense Oil & Polish Cleanser
·         DuPont PrepSol II™
·         Menzerna Top Inspection
·         Wurth Clean Solve

Mineral Spirits (White Spirit) are a petrochemical based product (Stoddard solvent) it also contains oils, so its use in a paint wipedown process is self-defeating as you’ll need to remove the oils from the surface

Notes:
1.      For dense (hard) clear coat use a very light dilution rate, for less dense(soft)clear coats use a more diluted solution, as  use too much alcohol will cause a micro fibre to offer more surface resistance and may cause surface marring.

2.      After the paint surface has been subjected to a chemical cleaning its protective layer (s)  have been removed and the paint surface left without protection, so it is very important that a wax or polymer protection  be applied immediately.

Alternative products

·         3M™ Prep Solvent-70 (#08983) is a low VOC, water- based solvent used to remove oils, wax, grease, and silicone from surfaces prior to the application of a coating. Effectively cleans metal, primed metal and painted surfaces. Use with 3M™ Panel Wipes (#4567) the Panel Wipes have excellent absorbency and are super strength when wet or dry. They are easy to carry and are supplied in an easy to dispense box.

·         CarPro Intense Oil & Polish Cleanser - is anti-static, reagent isopropyl alcohol (IPA) based cleaner designed to dissolve oil particles and remove polish residue to inspect the surface after polishing or to prepare the paintwork for the application of a coating product. Its intense cleaner dissolves oils and it also attracts the dust left by compounding. When you wipe down your vehicle with Eraser, you’re removing oils, fillers, and dust completely. Enabling a coating to form a stronger bond and create an even, long-lasting shine with a more durable protection.

·         DuPont PrepSol II™ - http://www.xurex.com/products.html) spray onto a 100% cotton or a micro fibre towel and clean the surface

 Groit’s Paint Prep - to remove wax, silicone polymers and oil from painted surfaces so products can properly bond to the surface. Paint Prep is easy to use and is safe for vinyl and rubber (not for use on glass)

·         Hi-Temp's H-23 Prep Wash - to prepare a paint surface for polishing, compounding, wax and / or polymer sealant application (especially if changing from a wax to a polymer product) this is a water-based paint cleaner designed to remove all traces of silicone, oil, and buffing residue from any exterior paint surface

·         Menzerna Top Inspection (PP95) – use to inspect your work, use this water-based cleaner that removes dust left by compounding and any lubricating oils so you can see the real results of your work. There are no silicones or fillers, just cleaning agents to uncover the real condition of your vehicle’s paint
·         Optimum Power Clean - Optimum Power Clean™ is an environmentally friendly, all surface-safe cleaner, used for paint dilute it 2:1

·         Wurth Clean Solve - is a fast acting cleaner and solvent that will not leave a film residue. It will quickly remove wax, tar, gum, grease, paint overspray, adhesive, oil, and silicone. It can be used on a variety of surfaces including: base coat, clear coat, aluminium, fibreglass, glass, fabrics and vinyl.

 Relevant Articles

1.      1. “A new perspective on paint defect return”, Jason Rose from Meguiar’s - http://www.autopia.org/forum/guide-detailing/112084-new-perspective-paint-defect-return-interesting.html

2.  2.     “IPA Wipe down”,  David Ghodoussi - http://www.autogeekonline.net/forum/auto-detailing-101/40688-ipa-wipe-down.html