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 is approached in conversations around how water and dust particles have a hard time sitting on or clinging 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 of the key benefits which paint coatings provide to vehicles, while also providing 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 the 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, usually making it inclined to fall off the surface with relative ease.
Contact Angle is a means of measuring the free surface energy of a solid surface when a liquid contacts it. Simply stated, contact angle works like this: 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. A very high contact angle, say 145 degrees, looks like almost three quarters of a very tight liquid sphere sitting on top of a surface. In this case, only small portion of the liquid droplet is touching the solid surface. A low contact angle, say 30 degrees, may look like a small pool with the majority of liquid spread out over a wide area actually touching the surface.
The terms Hydrophobic and Hydrophilic use the concept of contact angle to define how a solid surface interacts with a liquid. The word Hydrophobic literally 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 those which are hard to wet, meaning water will have difficulty attaching to the solid surface and 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 wetting it. There is almost no discernible difference of 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 it was even 4-5 years ago, since ceramic paint coatings have become a staple surface protection option. Therefore, detailers need a solid understanding of the technology and properties behind coatings as well as the 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 behind 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, altering the surface characteristics.
To Layer, or not to Layer Ceramic Nano Coatings or Waxes?
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 this impressively handsome wax is NOT the product you wish to keep on top of it; either for maintenance or as an additional sacrificial barrier of protection.
The ONLY thing you want 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, any topper product should remain in the same chemical family as the base paint coating. Remaining within a chemical family helps to maintain continuity of surface energy and ensures optimal adhesion of the topical product, while retaining 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, many protection characteristics of a paint coating depend on the ability to remain hydrophobic. And 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 paint 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. It does not mean the coating has failed, but rather it 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 is found on literally hundreds of online forums and social media groups, many times marketing related. Surface properties alone do not provide an accurate picture of a ceramic paint coating and its overall protection characteristics.
If a coating is not exhibiting perfect hydrophobic characteristics this does not mean its other protective qualities are also gone. 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 have judged and perpetuated the myth that a coating’s overall quality and durability relate to the surface performance. They have even gone so far as to claim the coating is gone within 6 months, due to a lack of hydrophobic water behavior. This is definitely not always the case.
When a coating ‘fails,’ to produce water beading or sheeting, most times topical surface contamination is the culprit. This contamination build up occurs for a number of reasons, but most frequently improper wash intervals 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 is allowed to build 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 mean a ceramic coating or wax is gone or has failed? No, not necessarily. Most likely it indicates the surface is contaminated and therefore masking the properties of the LSP.
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 are better suited to 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.
► For Service Inquiries or Fill out our SERVICE INQUIRY Form
or call OCDCarCare (949)-427-1191► ►Follow OCDCarCare on: Instagram, Facebook, and Google +
Latest posts by Christopher Brown (see all)
- Safest Waterless Car Wash Method for Auto Detailing: Article & Video - 30 January, 2018
- Automotive Surface Care For Ceramic Nano Coatings Explained - 18 December, 2017
- Scratch: A Customer Email & FeynLab’s Heal Lite Self Healing Nano Coating - 22 June, 2017