Surface Energy: A Discussion of How Wax & Automotive Ceramic Nano Coatings Function in Auto Detailing.
By Christopher Brown of OCDCarCare Los Angeles – OCDCarCare.com – 17 Jan 2017
Surface Energy, What on Earth is that?
Surface Energy, in auto detailing terms, is the discussion of how water or contaminants interact with a vehicle’s surface; usually paint. Typically, this subject appears in conversations surrounding the ability of water and dust particles to cling to a surface. In auto detailing, this is a positive surface attribute because low Surface Energy causes water beading, water sheeting, and helps vehicle surfaces to remain cleaner. In terms of ceramic paint coatings, Surface Energy is crucial because it explains many key benefits which paint coatings provide to vehicles. Additionally, understanding surface energy provides insights to detailers which can help when troubleshooting potential surface issues.
Surface Energy Scientifically Explained
Surface energy is a measure of a solid surface state. If free surface energy is at a high level then liquid will have great success adhering to that surface. Conversely, the lower the surface energy, the more difficulty a liquid has to adhere or stick to a surface. Usually causing it to fall off the surface with relative ease.
Contact Angle measures the free surface energy of a solid surface when a liquid contacts it. Simply stated: the higher the contact angle measurement, the more difficulty a liquid has adhering to a solid surface. Contact angle is measured between a liquid droplet’s edge and the solid surface it rests upon. At a very high contact angle, say 145 degrees, water appears as almost three quarters of a very tight liquid sphere sitting on top of a surface. Therefore, only small portion of the liquid droplet touches the solid surface. At a low contact angle, say 30 degrees, water appears as a small wide pool, touching the surface.
The terms Hydrophobic and Hydrophilic use contact angle to define how a solid surface interacts with liquid. The word Hydrophobic translates to “fear of water.” A surface is Hydrophobic when liquid contacting it contains a contact angle of 90 degrees or greater. Hydrophobic surfaces are hard to wet. Water has difficulty attaching to the solid surface, therefore appear to sit on the surface.
On the other hand Hydrophilic “friend of water” surfaces have contact angles below 90 degrees. Think of pouring a glass of water onto a typical sidewalk. The water easily rests onto the concrete. There is almost no discernible difference between the water and the concrete. They seem to fuse together to make — wet concrete.
Most simply: contact angle quantifies the ‘wettability’ of a solid surface by a liquid.
How Surface Energy is Relevant and Important in Auto Detailing
Surface Energy of automotive surfaces is a topic rarely discussed, yet carries much significance in today’s detailing climate. Without an understanding of this concept, it may be difficult for detailers to evaluate and plan solutions for common auto detailing issues arising from the behavior characteristics of vehicle surfaces.
Surface Energy is even more relevant today than ever, since ceramic paint coatings have become a staple surface protection option. Therefore, detailers need a solid understanding of the technology and properties behind ceramic nano coating technology. This may prove invaluable for relevant issues that may arise around ceramic nano coating upkeep and maintenance.
This article came to fruition because little to no information or resource regarding this subject exists to educate consumers or detailers. This article’s concepts primarily focus toward the performance and characteristics of ceramic nano coatings. However, MOST of this information is applicable to the understanding the surface characteristics for all Last Stage Products (LSP’s); including waxes and sealants.
How Changes to Surface Energy on a Vehicle Causes Hydrophobic Surface Behavior
ALL LSP’s including Waxes, Sealants, and Ceramic Nano (aka Glass) Coatings were partially engineered to protect vehicles by keeping surfaces clean. The amount of Surface Energy an LSP creates accounts for its ability to repel contaminants and liquid off of vehicle surfaces. Surface Energy is also the scientific explanation of how wax beads and ceramic coatings to sheet water. The common detailing industry term often used to describe water beading or sheeting is ‘hydrophobic;’ literally meaning afraid of water.
When anything layers on top of an LSP; such as dirt, topical contamination, or another product, the Hydrophobic properties of that LSP can change. Regular vehicle wash schedules assist in keeping vehicle surfaces clear of contaminants. This is the only way to ensure surfaces remain hydrophobic for extended periods of time.
In regards to coatings specifically; often the public, or even some detailers, quickly proclaim a coating has failed when it stops sheeting water. This is not entirely the case when investigating the matter at a surface level. Most times, a coating “failure” is due to topical contamination or something else layered on top of the coating. This altere the surface energy characteristics.
To Layer, or not to Layer or “Top”, Ceramic Nano Coatings?
As a wax, Swissvax Concourso is a stunning choice for automotive finishing. Its high carnauba content causes vehicles to glow with a sexy cinematic halo around them, creating a gorgeous presence. However, if a vehicle has a ceramic nano coating applied to its surface, then even handsome wax is NOT the product you wish to maintain it with. Even if adding as an additional sacrificial barrier of protection.
The ONLY thing to layer or top a coating with is a long term silica sealant or another semi permanent coating product. These types of products are commonly referred to as ‘toppers’. Preferably, a topper product should remain in the same chemical family as the ceramic nano coating. Remaining within a chemical family maintains continuity of surface energy and ensures optimal adhesion of the topical product. This also retains the original properties that base coating provides. Putting anything else over a ceramic paint coating, other than these types of topper products, alters the surface energy. As stated previously, some protection characteristics of a paint coating depend on the ability to remain hydrophobic. This ability is maintained through low high surface energy.
The Fickle Nature of Ceramic Coating Surface Energy
The surface energy, and most of the measurable performance characteristics, of ceramic paint coatings are quite fickle if not maintained. It is actually quite simple to drastically alter the surface energy of a coating.. This is the exact reason why most coatings companies insist/stress regular wash intervals for coated vehicle surfaces. With regular maintenance, coating properties remain optimal, allowing vehicle owners the ability to visibly identify the coating’s hydrophobic abilities. Ease of maintenance and the ability to keep vehicle surfaces clean are prime benefits and selling points of ceramic nano coating technology. This occurs because the coating maintains it original intended outermost surface energy properties. Therefore, adding anything which drastically alters the ceramic nano coating’s original surface properties is highly inadvisable.
The Detailing Industry and Misinterpretations of Surface Energy Behavior
A change in surface energy alone is never a reliable indication of coating failure. Hydrophobic ‘failure’ could easily happen by smearing olive oil or a finish polish over a coated section. Whatever residue remained after wiping the surface would alter the surface behavior of that coated section. Therefore, this example only indicates that surface energy has shifted from the ideal characteristics of the coating. This does not automatically mean coating failure, but rather its hydrophobic properties are masked by whatever was put on top of it.
Often, customers or detailers form snap judgements or conclusions about ceramic coating effectiveness or durability based on hydrophobic properties. Frequently these opinions are without a true or full understanding of the principals behind vehicle surface energy. This type of uninformed dialogue floods literally hundreds of online forums and social media groups, many times marketing related. Surface characteristics alone do not provide an accurate picture of a ceramic nano coating and its overall protection characteristics.
When a coating ‘fails,’ to produce water beading or sheeting, most times topical surface contamination is the culprit. This contamination build up most frequently from infrequent wash intervals that allow contamination to layer and cover the coating’s surface. Detailers and consumers can avoid falling into the pitfalls of misjudging products with better knowledge. Therefore, the understanding how surface energy affects hydrophobic characteristics for surface performance and longevity is crucial.
Final Words on Surface Energy, Ceramic Paint Coatings, and Waxes in Auto Detailing
Vehicle surfaces require regular maintenance (washing) in order to keep them free of topical contamination. Proper vehicle surface maintenance optimizes the effects of ceramic nano coating water sheeting or the ‘super sexy’ tight beading of waxes. If contamination builds up, eventually it morphs into the outer most layer of a vehicle’s surface. Therefore, the paint adopts the surface energy properties of this outermost contamination layer. Does this automatically equal ceramic coating or wax failure? No, not necessarily. Most likely the surface is highly contaminated, therefore masking the properties of the LSP.
If a coating exhibits poor hydrophobic characteristics this does not mean its other protective qualities are also gone. Ceramic Nano Coating benefits and protective capabilities of: UV protection, chemical resistance, improved topical hardness, additional gloss, and measurable thickness; do not vanish if the surface does not sheet liquid. Unfortunately, and quite commonly, portions of the detailing community judge and perpetuate the myth that a coating’s overall quality and durability relate to the surface performance. Some even boldly proclaim the coating is completely failed within 6 months, due to a lack of hydrophobic water behavior. This is definitely not always the case.
Next time you think a ceramic nano coating or wax is ‘bad’ or has ‘failed’, consider the vehicle’s surface energy. Surface energy always plays a critical role in surface care within automotive detailing. However, when armed with an understanding of the science and properties associated with surface energy, detailers may better troubleshoot possible surface issues.
~Keep on Buffin’
© Christopher Brown of OCDCarCare Los Angeles – OCDCarCare.com – 2017
|For more auto detailing and car care related topics please browse: OCDCarCare Los Angeles’s – Auto Detailing Article Archive
His passion & dedication to car care lead him to writing in-depth articles about detailing in order to share with the car enthusiast & detailing communities. This lead to detailing training courses designed to develop skills, confidence, and results, enabling detailers to increase quality, efficiency, and profitability.
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