Volume 50, Issue 5 - May 2015

Does it Really Do That?

The Suppliers of Low-Maintenance
Coatings Tout Lots of Benefits.
Which Ones Pan Out?

by Megan Headley

Low-maintenance glass products are designed to make glass applications, including façades, easier to clean compared to untreated surfaces.

As with every niche, the emergence of low-maintenance coatings (i.e., easy-to-clean) in the 1980s led to the rise of a new market within an industry. More than 100 companies around the world now offer fabricators an easy-to-apply option for adding new value to glass.

You may have talked to several suppliers promising best-of-industry performance—most durable … water repellant … oil repellant … protection from concrete and construction grime. Each product is a bit different from the rest. So how do you make sense of all the various claims when selecting a product for your operation?

Apples and Oranges

One reason for the different claims among suppliers is that the chemical composition of each coating varies. The U.K.-based Glass and Glazing Federation describes five categories of technology for liquid-applied glass surface treatments in its November 2013 publication, “Surface Modification of Glass for Ease of Maintenance”:

• Bi-functional silane;
• Polymeric resins;
• Reactive silicone fluid;
• Sol-gel silane; and
• UV-cured silane.

The silane products are described as coatings, versus treatments that react to and become a part of the surface of the glass. (For the purpose of this article we are going to use these terms interchangeably.)

Among those five categories, more than 150 manufacturers have cropped up worldwide to offer their unique take on low-maintenance enhancement. So how do you find the best one for your product?

“At the end of the day, it is quite subjective when measuring the performance of coatings. Each coating is marketed differently and claims different performances,” says Gareth Francey, vice president for Bohle America Inc. in Charlotte, N.C.

Adam Zax, president and CEO of Diamon-Fusion International in Irvine, Calif., suggests starting with the basics. “It really depends on what attribute the consumer needs,” he says. “For exterior applications, tests [for example, EN 1096-3 for UV weathering] showing durability of the coating when exposed to UV light will be important. For solar applications, tests showing if the coating blocks any part of the light spectrum can be critical.”

Talking to your supplier about what you want to offer your customers is a great place to start—but without understanding the real benefits of these coatings, it’s possible to get lost in misinformation and exaggerated claims, cautions Stephen Byers, managing director of U.K.-based Ritec International Ltd., the manufacturer of ClearShield.

“We believe the industry … is under serious threat caused by repeated failures of some suppliers to inform their customers about product performance based on real-life experience instead of laboratory testing, as well as multiple risks to health and safety,” Byers says. He adds, “We are working hard to avoid situations such as those involving ‘self-cleaning’ glass.”

By this, Byers means providing incomplete information or over-selling a product’s true capabilities, such as the hype around “self-cleaning” glass products developed in the early 2000s. These products didn’t actually clean themselves, but rather required less maintenance than standard glass products.

As with self-cleaning glass, a single overblown claim from one over-enthusiastic supplier is enough to cast doubt upon an entire industry.

“In some countries, such as South Africa, this situation caused a number of legal actions, which resulted in some glass and glazing companies avoiding the use of any glass surface treatment or coating at all. It has taken years to remedy this situation, and the job is not yet complete,” Byers says.

Ritec performs both lab and field testing to ensure performance of its products.

Comparing Durability

Byers’ first claim, about the failure of suppliers to inform customers about product performance based on real-life experience, is based on durability. Ritec has been field testing since the development of the ClearShield system began in 1981. “It was initially made available to marine markets on the basis that, if it works on a cruise ship or ferry exposed to aggressive conditions 24/7, it will work anywhere,” Byers says, adding that field experience is the only “meaningful way of measuring or comparing the differences in performance or durability.” He cites several studies within the coating industries1 that agree that “it is a fact that no laboratory test alone, or any combination of tests, can predict the performance or durability of a glass surface treatment or coating.”

It’s hard to argue against experience as a good indicator of performance, but it’s also a stretch to claim that laboratory testing is not. A better argument, perhaps, is to consider whether your supplier is promoting potentially subjective in-house or impartial third-party testing—and whether their warranty is backing up the claims that are important to you.

On the other hand, customers do find a field-tested product offers a powerful argument. While Arnie Harris, president of Heights Glass & Mirror in Chicago, switched to DFI’s coatings on its Euroview Shower Door product to increase the company’s profit margin, he notes, “It’s proven itself in the many years that we have used it.”

But another factor to consider is to know upfront if reapplication or “revitalization” of the coating is necessary. In some cases, a claim for durability requires repeated applications of a coating. In other cases, it means simply following proper maintenance procedures to ensure the end-user of the glass isn’t rushing along end-of-life performance for this coating.

For example, Byers says his company guarantees “performance and durability as long as the complete, cost-effective ClearShield Eco-System is followed. Whenever this may not be feasible, we provide guidelines based on actual field experience under similar conditions.”

Re-application certainly wasn’t a deal-breaker for Harris—but a difficult reapplication process might have been. “If we do have to go into the field to make a service call, DFI has products where you can just walk into the customer’s house and do the service without having to put a hazmat suit on,” he says.

Meanwhile, Bohle’s BriteGuard Surface Sealer, introduced in 2011, is marketed with a 10-year warranty. “This warrants that the coating will not discolor, change or destroy the appearance of the glass surface. We also warrant that the glazed surface material will remain corrosion-free, and ultimately keep its repellent effect as long as the coating is not removed through harsh cleaners or mechanically removed by scraping with rough cleaning material,” Francey explains. A “BriteGuard Refresher Kit” is supplied in the event that the coating is degraded. “As the name states, the original coating is ‘refreshed’ through a one-step manually applied wipe-on application,” Francey adds.

The Diamon-Fusion protective coating comes with a 15-year warranty on architectural glass in nonresidential applications; the warranty can be extended to 30 years if DFI’s authorized revitalization requirements are met.

Warranties may vary, but so does the fine print, so be sure to talk to your supplier about treatments that may void this guarantee.

However, Byers adds one more durability factor to consider: shelf life. Sol-gel coatings typically have a shelf life of 18 months or less following the date of manufacture, according to information from Ritec.

Safe Application

Byers’ second claim, about the risks to health and safety posed by these products, is more serious.

“From a health and safety point of view, many glass and glazing companies are without doubt at serious risks of harm to their workers, visitors and property. These risks are caused by suppliers, governmental agencies and glass trade associations failing to inform companies about the risks and dangers [of application]. With the correct knowledge, companies can carry out proper workplace risk assessments and make informed decisions, including the use of required personal protective equipment (PPE) for their workers,” Byers says. “Actions are being taken by health and safety authorities in many countries to remedy the situation described above.”

Ritec’s research shows that certain coating suppliers fail to disclose the use of substances that are banned or regulated, among other issues. “Furthermore,” Byers notes, “some suppliers contradict warnings in their own Material Safety Data Sheets (MSDSs) …

Adrian Ray, director—Americas, International Business Development, PCT Global LLC, the Australia-based manufacturer of EnduroShield, agrees that implementation is of great importance. “There has to be more than just a transaction that involves the sale of a coating and along with that providing the instruction sheet. You are engaging in a business relationship.” His company offers customized implementations based on scale and requirements; this includes the required safety, regulatory and PPE documents, as well as advanced independent handling documents. “This is combined with, personalized training and certification of the fabricators location(s), warranty support and marketing support,” Ray adds.

“While DFI has never had such an issue, we have heard of competitors’ spray-application processes being shut down by regulators in certain facilities,” Zax says. “We applaud this effort to keep the workplace safe, but we also understand the burden it can put on fabricators and manufacturers.”

Making the right choice upfront can reduce that burden. For starters, it’s crucial to read the MSDSs for all products, and recognize that applying such products may require PPE beyond what’s currently used by your team. It’s also important to recognize that each coating type carries different risk factors.

“As there are many different chemical make-ups of coatings available to the market, the safety risks in application are all a little different,” Francey explains. “For the solvent-based products, the risk of spraying and application is there, but can be managed through correct PPE and workplace conditions.”

Francey says solvent-based products such as the BriteGuard Surface Sealer have a risk of a fine spray being inhaled during the application process as well as catching fire if applied near a flame. As a result, the manufacturer is “clear and strict” in its instructions that applicators apply the product in a well ventilated room with proper PPE, to include gloves, mask and glasses.

Francey further explains, “The nanotechnology products are potentially risky if there is contamination with the body cells, so they may require special protection or devices when applying these products. Silicone-based coatings are less risky, but could be hypo-allergic to people applying this.”

If an MSDS is not easily obtainable, from your supplier, that should set off a warning bell. “The responsibility of any health risks should be mutually shared with the company applying the coating as well as the manufacturer of the coating through a clear understanding of the application process and guidelines. Technical Data Sheets and Material Safety Data Sheets need to be well maintained and be made easily available,” Francey says.

Cutting corners is a poor way to build repeat business, and companies that plan to stay in operation bank on return customers.

In fact, the acknowledged safety risks led DFI to develop a solution for its fabricators.

“Better safety is one of the key value propositions of DFI’s self-contained, fully automated, patented Diamon-Fusion vapor deposition system, what we call the FuseCube,” Zax says. “Having received ‘blanket’ approval from the South Coast Air Quality Management District —one of the strictest regulatory bodies in the world, and part of the Environmental Protection Agency—it is one of the safest ways to apply a protective coating …”

Making a Choice

So how do you decide which glass treatment best meets the needs of your customers?

For Harris, that meant finding a solution that “would give us the greatest margin of profit, the easiest application and be able to offer something that we could market to our customers that was different than the other products available on the market.”

You might consider the following:

1. The claims made by the supplier. Do you want to protect from construction grime or simply lower window-washing expenses? What types of stains are problematic for clients?

2. What sort of investment must you make to get started? Don’t focus on the lowest cost, but the most thorough explanation of safe application.

3. Can your facility provide the protection needed to apply this product? If special applicators are required, it’s important to know that upfront. Make sure potential suppliers include a MSDS.

4. What is covered by the warranty? The length of the warranty is important, but perhaps not as important as the criteria that must be met to keep it active and ensure that promised characteristics are covered.

5. How much training and/or technical assistance is provided by the supplier? The suppliers who spoke to USGlass offered assistance ranging from multi-lingual technical information, to onsite training or online support, to application videos and start-up kits.

Is Contact Angle the Best Indicator of Performance?

For many years, contact angle has been used to describe low-maintenance glass coating’s effectiveness at shedding water and contaminants.

Contact angle measures the water repellency of glass. The more water-repellant the glass surface, the more water will bead off, taking with it the minerals and contaminants that typically cause stains.

But according to Adam Zax, president and CEO of Diamon-Fusion International (DFI) in Irvine, Calif., contact angle may only be half of the equation.

“While contact angle can still be valuable, we’ve learned that much of what we thought contact angle told us was actually better described by sliding angle,” Zax says.

Sliding angle, according to information from DFI, measures a surface’s “slickness.” The angle is measured by placing a drop of water on a piece of glass and tilting the glass; the angle at which it is tilted when the water begins to slide is the sliding angle. The lower the sliding angle, the slicker the glass and, according to DFI, the easier the glass is to clean.

“Because ‘cleanability’ is a key value proposition of our kind of protective coating, for years the industry had been looking for a way to determine which coating performs best in this regard so we can properly inform consumers on this key attribute,” Zax says.

Zax became convinced of the importance of sliding angle while working with automotive engineers, who look at this factor to help them determine the speed at which water will slide off the windshield, providing better visibility.

“The stickier the surface, the faster the car had to go to get the water to bead off, so ultimately sliding angle tells us how easy that surface is to clean. A sticky surface is reported to the engineers in the form of a higher sliding angle. While working with this group about a year ago, we had our ‘aha’ moment,” Zax explains. “In what seemed like a commonsense realization, but had yet to be made by anyone in our industry, we discovered that having a measure of how sticky a surface is gives us a way to measure how easy or difficult it is for water and contaminants to come off that surface. How easy or difficult water and contaminants come off the surface defines how easy that surface is to clean.”

It’s a convincing argument, but one that doesn’t necessarily take into account the differences among various coatings.

According to Adrian Ray, director— Americas, International Business Development, for PCT Global LLC, the Australia-based manufacturer of EnduroShield, “Sliding angle is more relevant for thicker coatings that fill the irregularity of the substrate, but may lead to other problems such as slipperiness and difficulties in handling and potential failure of silicone sealants. The EnduroShield product, being of lower applied film thickness, does not even out the glass irregularities and has a slightly higher slip angle. This reading shows insignificant differences in the easy-to-clean properties.”
And, of course, until other testing bodies jump onto sliding angle as a proof of performance, there will be little data to compare.

“We do not test for the sliding angle,” says Gareth Francey, vice president of sales for Bohle America Inc. in Charlotte, N.C. “The contact angle, or angle formed between a drop of liquid and a solid surface, is the measure that the TÜV Rheinland states as the indictor that the coating is performing.” (Note: TÜV Rheinland is a worldwide provider of technical services. Headquartered in Cologne, Germany, its “mission and guiding principle is to achieve sustained development of safety and quality in order to meet the challenges arising from the interaction between man, technology and the environment.”)

Zax calls this “the old way of looking at this category of coatings simply as ‘hydrophobic’ rather than as ‘easy-to-clean’ which is the value proposition most manufacturers in this category are promising … [I]t is correct that contact angle measures the performance of a water-repellant, or hydrophobic coating. To the consumer’s detriment, historically this is where coating manufacturers … stopped. A coating can be very repellent, thus have a great contact angle, but still be very ‘sticky,’ so water and other material won’t easily slide off. Until DFI did it, no one looked deeper into what really makes their coating ‘easy-to-clean’ and how to measure that attribute. When DFI did it, we found the way to measure ‘easy-to-clean’ is sliding angle. Once they and the rest of the industry understand the science behind it, they will begin measuring it too. Whether they report it or not will frankly depend upon how they compare to the competition.”

1. Among the studies and papers cited, are the following: Australian/New Zealand Standard 1580/457/1:1996 – Paints and related materials – Methods of test – Method 457.1: Resistance to natural weathering; “No single cycle or device can reproduce all the variables found outdoors in different climates, altitudes and latitudes. One is a constant condition, whereas the other is variable.” Printed in “Shedding light on laboratory weathering,” Paint and Ink International, January 1996, page 2; “In spite of the longstanding general agreement that ‘salt spray’ results do not correlate well with the corrosion seen in actual atmospheric exposures, for many years salt spray exposures have generally been accepted as the standard corrosion test method.” Printed in “Combined corrosion/weathering exposures: A status report; The combined corrosion/weathering cycle tests improves industrial maintenance coating test results,” by Patrick J. Brennan and Steven J. Grossman, Paint and Ink International, 1996; “Of course all these calculations only give an idea about the time a product might last, it isn’t possible to predict exact periods of time.” Printed in “Practicable Methods in Environmental Testing” by Eduard Pohle and Leopold Kranner, Research Institute for Chemistry and Technology, Vienna, May 11, 2005.

the author

Megan Headley is special projects editor for USGlass magazine.
She can be reached at mheadley@glass.com.

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