SELECTING EXTERIOR TOPCOATS BASED ON AESTHETIC PERFORMANCE This presentation focuses on EXTERIOR topcoats and the aesthetic performance of different generic types based on color and gloss. It does not include surface prep, primer or intermediate coats, or corrosion protection.

COATINGS & ULTRAVIOLET LIGHT

What is a Coating Polymer? A carbon chain created primarily with by-products of the petroleum industry. These polymers, also known as “resins”, provide the framework for which the coating’s performance is built upon Examples of a coating polymer include: Epoxy Urethane Acrylic Fluoropolymer

What Causes Coating Degradation? Light Exposure Primarily Ultraviolet (UV) light, along with oxygen and water, can induce slow degradation (aging) of many organic polymers found in coatings Elements Temperature fluctuations, pollution, chemical exposures, rain, etc. can also contribute to degradation, usually accelerating the process Gloss loss, fading, yellowing, peeling, loss of tensile strength and delamination can be caused by these two factors.

Radiant Energy The Earth’s atmosphere filters and absorbs most of the more powerful shorter wavelength radiation, including UV light. The Earth’s atmosphere filters and absorbs most of the more powerful short wave radiation. Only a small amount of long wave UV light (between 300 and 380 nm) reaches earth. However, even these small amounts can cause damage on the molecular structure of coatings. (Glass allows visible light to pass through but blocks most UV light, providing longer life to interior coatings.) This radiant energy from UV wavelengths causes molecules of the polymers to become excited and can break a coating’s chemical bonds, damaging the film.

Responses of Radiant Energy Transmission UV light harmlessly passes through film to the substrate Reflection Although transmission through the coating does not affect the topcoat, coatings or substrates beneath it can be adversely affected by UV. Reflection could be due to specialty pigments, such as aluminum, that are included in the coating. Absorption is the most common type of response to UV. This response could be attributed to specialty pigments included in the coating formulation. Just as the sun damages unprotected skin, a coating that absorbs UV radiation and cannot dissipate it will be damaged. Free radicals are the result of a reaction within the polymer that begins to pull polymer bonds apart. This is a very complicated chain reaction that is presented in a basic form here for the purpose of simplicity. The chain reaction will continue in a damaging form as long as the coating is exposed to UV radiation. Coatings absorb UV light and create free radicals: Polymer degradation (i.e. fading, chalking), Creation of chromospheres (i.e. yellowing). UV light is reflected from coating surface Absorption Coatings absorb UV light but dissipate it as harmless heat

Mechanisms of Coating Degradation UV light absorbed by a coating excites the polymer, raising the energy level that must be eliminated This energy breaks the primary polymer bonds, creating free radicals and begins a chain reaction of degradation if UV exposure continues Depending on resin type, once degradation begins, a rapid breakdown will occur Polymers with stronger bonds (i.e. urethanes & fluoropolymers) have more resistance to UV light induced breakdown at any given wavelength. The second bullet describes a conversion from radiant to chemical reaction.

Increasing UV Resistance UV Resistant Binders Reflective Pigments UV Absorbing Pigments UV Inhibitors Pigments, fillers and additives, especially inexpensive ones, are vulnerable to free radicals and can begin the degradation process that can then attack the binder. This is why a pure urethane can still be affected by UV light. UV Resistant Binders: Coatings using aliphatic polymers that do not absorb UV light (i.e. fluoropolymers, polyurethanes) resist these damaging effects. Non-UV absorptive binders can still be affected by free radicals originating from other UV sensitive materials in the coating. Reflective Pigments: Pigments such as aluminum and titanium dioxide can be used to reflect UV light and inhibit absorption. Mixed metal pigments reflect infrared (IR) light to reduce solar gain. UV Absorbers: Specialty pigments that absorb UV light and dissipate the energy as harmless heat, protect the binder and extend coating life. UV absorbers do exactly what the name implies, they absorb UV radiation and dissipate it as harmless heat, keeping free radicals from breaking the polymer bonds and degrading the coating. However, just like the UV absorbers found in common sunscreen, at some point their protective ability will be used up and UV will begin attacking the polymer bonds. Think about putting sunscreen on and laying in the sun for an entire day. You will likely still burn but it will take much longer, and be less severe, than tanning without the protection of a sunscreen. Most “UV packages” contain both absorbers and inhibitors for optimum protection. Once the absorbers are exhausted, protection is still provided by inhibitors. These packages can be part of the standard formulation, factory added upon request or field added. UV Inhibitors: Specialty additives can be selected that inhibit degradation of the binder or interfere with reaction of free radicals. UV inhibitors can be combined with UV absorbers to provide maximum protection.

PIGMENT SELECTION

Organic vs. Inorganic Organic Pigments Synthetic Less color stable than inorganic Bright organic colors are less expensive than bright inorganic Inorganic Pigments Naturally occurring; metal based Color stable Less susceptible to free radicals Bright colors are more expensive to produce Many people become confused between the terms “organic” and “inorganic” as they relate to pigments. While “organic” is often used as a synonym for “natural” it really refers to carbon-based materials. Organic pigments are derived from carbon-based materials such as petroleum and then refined, thus the name, organic pigments. Since they are refined in a laboratory, brighter colors are easier to produce. “Inorganic” describes materials that do not contain carbon. In the case of pigments, this includes metal based materials that are mined from the earth. Because they are not “organic”, they do not break down as readily and therefore hold their color better. However, because they are taken from the earth, clean bright colors are more difficult, and therefore more expensive, to find and refine. That is why many inorganic colors are earth-tones or a duller, dirty shade.

Pigment Quality There are various grades of both inorganic and organic pigments Quality and performance can depend on: Material make-up Carbon content Pigment color Technology (organic vs. inorganic) Resistance to free radicals

EFFECTS OF ULTRAVIOLET LIGHT COLOR AND GLOSS

Ultraviolet Light (UV) on Color & Gloss Damage caused by UV light can discolor the binder, fade pigments and affect gloss The shown blue panel was subjected to 10,000 hours of VU exposure. One side of the panel coated with a highly sustainable fluoropolymer and the other with a polyurethane. Note the difference in appearance. Neither side of the panels had substantial color change; the gloss change however, thus the appearance to the observer, is significant on the polyurethane side. Acrylic Polyurethane FEVE Fluoropolymer Panel demonstrates coating performance after 10,000 hrs. QUV-A Exposure

Viewing Gloss Rough surface of coating could be formulated or caused by UV damage. The same color can appear quite different when viewed as a high gloss or a flat finish. Loss of gloss can be a major factor in the “color change” of a coating that has been damaged by UV. Architects should consider gloss retention performance, even of lower gloss finishes, to help ensure the loss of gloss does not affect how the “color” is viewed. High gloss Low gloss High gloss – Light is reflected causing coating to look brighter Low gloss – Light is diffused causing coating to look duller

Viewing Color Color, or color perception, can be greatly affected by a light source or type Color indoors can be perceived much different than the same color outdoors Exact color and color differences can be determined using color equipment View color selection in same light source as exposure.

Comparing Color Color and color differences can be measured in Delta E (DE) in different ways: CIELAB2000 CMC FMC II Hunter Measurement scale should always be stated when comparing color The way in which color is seen and measured is extremely technical and could be a presentation unto itself. For reasons of time, this is the only slide that addresses it. These are the four basic measurements of color and it is important for architects to know which one is being reported when comparing product performance. Tnemec has historically used FMC II but is currently using CMC.

TOPCOAT SELECTION BASED ON GENERIC TYPE

Generic Coating Types Epoxies Alkyds Acrylics Polyurethanes Polysiloxanes FEVE Fluoropolymers The most commonly encountered generic types are included in this comparison. Control 6 Months Exp. Waterbased Epoxy (black)

Epoxies UV Light Performance Poor UV stability Color Yellowing of binder Fading of pigment Chalking Gloss Extreme loss Chalking is the result of the binder degrading and the pigment being exposed. Epoxy was included here for the sake of discussion, and while it is used as a topcoat for barrier protection, it should not be considered an aesthetic topcoat. These chemical and abrasion resistant coatings generally degrade in UV light due to absorption by a polymer chain in the binder. Epoxies are not recommended as topcoats when aesthetics are required. Control 6 Months Exp.

Alkyds UV Light Performance Poor to moderate (depending on quality of oil) Color Some discoloration of binder Fading of pigments Chalking Gloss Will decrease at an accelerated rate Alkyds are commonly used because they are easy to apply (1 component) and inexpensive. However, they can not be expected to provide suitable color and gloss retention for more than a few years, especially in sunny environments. Alkyds’ convenient application make them widely used and can provide basic UV performance if comprised of quality materials. Alkyds’ convenient application make them widely used and can provide basic UV performance if comprised of quality materials.

Acrylics UV Light Performance Good to very good Color Little change to binder Possible fading of pigments Gloss Moderate rate of loss Acrylic resins themselves are not highly affected by UV. However, to meet the lower price points customers expect to pay for them, manufacturers use inexpensive additives and pigments that then become the weak link in the coating and attribute to susceptibility to free radicals. While acrylic binder is not highly affected by UV, additives used to decrease cost and lower priced pigments can cause performance to decrease dramatically.

Aliphatic Polyurethanes UV Light Performance Very good Color Little change to binder Slow fading of pigments Gloss Slow rate of loss Binder is not highly affected by UV, but less costly additives and pigments can greatly affect performance. Generally provide good color and gloss retention. True polyurethanes have good resistance to the effects of UV, however some manufacturers add less expensive additives and pigments to decrease the product price. This results in lower color and gloss performance even though it is still technically a “polyurethane”.

Polysiloxanes UV Light Performance Very good Color Some yellowing of binder (epoxy) Less potential fading of pigments Gloss Slow rate of loss Polysiloxanes typically utilize epoxy, acrylic or urethane binders. Those with acrylics and urethanes will outperform epoxy versions in both color and gloss.

FEVE Fluoropolymers UV Light Performance Excellent Color Outstanding binder Very good pigment tolerance to UV exposure Gloss Extremely slow rate of loss One reason fluoropolymer perform better is due to the expensive resin used in it. Because of the cost, manufacturers are more likely to use high priced, and better quality, color pigments and other additives. Exhibit excellent pigment compatibility, enabling a broad range of colors. Offering brighter, more vivid colors. They also offer a broad range of gloss possibilities Because FEVE coatings can be field applied, they are ideal for recoating applications. Provide excellent bonding to substrates ranging from aluminum and steel. Bond well with primers and undercoats such as epoxies and polyurethanes. Can be easily recoated and used to repair and refinish other fluoropolymers. Fluoropolymers’ utilize binders that have a tenacious chemical bond, which are not highly affected by UV and typically use additives and pigments of high quality that do not affect color and gloss performance.

Years Between Touch-Up/Recoat Life-Cycle Cost of Topcoat – Aesthetics Only 20 Year Life-Cycle of 30,000 FT2 Polymer Type # of Applications Years Between Touch-Up/Recoat Service Life Final Cost Alkyd 5 3-4 Years 20 Years $ 230,625.00 Acrylic 3 4-6 Years $ 140,625.00 Polyurethane 2 7-10 Years $ 96,000.00 Polysiloxane 10-15 Years $ 77,625.00 Fluoropolymer (FEVE) 1 15-20 Years $ 71,250.00 **See “TNE008_Slide_19_extranotes. pdf” for notes for this slide. (Found in Continuing Ed. Prog. folder on T-Net) Note: Figures listed are for topcoats only; they do not include primer and intermediate coat application and material costs.

OTHER CONSIDERATIONS COATING PERFORMANCE AND TESTING

Other Factors, Which Can Affect Aesthetics Surface preparation Coating compatibility Complete coating system selection Performance for specific environments Application equipment & technique Specification requirements Of course there are many more things that contribute to coating performance, durability and aesthetics. However, this presentation concentrates only on color and gloss performance as they relate to UV exposure. This slide is intended to acknowledge the other important aspects to consider when specifying a coating or coating system.

Writing Specifications Write performance based specifications with standards and minimum result requirements Place coatings in Division 9: Section 09 96 00 High- Performance Coatings Utilize Division 9 “Sub-Sections” to better define the scope of work & differentiate critical design elements Seek assistance for side-by-side comparison of products considered for substitution Request slight, but noticeable variation in color between intermediate coat and topcoat to ensure proper coverage. “Purity of Resin Formula” means “is the formula a hybrid or modified resin?” 09 96 00 – High-Performance Coatings section of MasterFormat 2004

Specifications By incorporating performance standards into a specification, the owner is assured suitable, high-quality products South Florida/Arizona exposures AAMA (weathering standards only) EMMAQUA: ASTM D 4141 QUV: ASTM G 53 or ASTM D 4587 Prohesion: ASTM G 85 Salt Fog: ASTM B 117 The next few slides will better describe each of these tests and acceptable results.

Exterior Testing Florida Exposure Various angles to the sun Extreme sun exposure Salt air and spray Arizona Exposure Intense Heat Various exposure angles Minimum cloud cover to maximize radiation exposure Dry harsh conditions Florida Exposure Various angles to the sun Extreme sun exposure Salt air and spray Arizona Exposure Intense Heat Various exposure angles Minimum cloud cover to maximize radiation exposure Dry harsh conditions

Real World Limitations High-performance coating systems could take 20 years before coating degradation Coating technology is dynamic and initial performance results are required quickly

Accelerated Testing Natural exposures can take years to obtain results Accelerated testing is utilized to emulate natural exposures with high concentrations of elements. UV Exposure Sunlight Concentrator EMMAQUA UV/Prohesion Humidity

Accelerated Weathering UV Exposure (QUV-A) Closely simulates natural sun Cycles Include: 4 hours UV/4 hours condensation 8 hours UV/4 hours condensation EMMAQUA Equatorial mount with mirrors and water Intensity of 8 suns Tracks sun movement In addition to natural exposure, long-term protection of an exterior topcoat can be confirmed with a UV (ultra-violet) cabinet and an EMMAQUA device. Both devices introduce the UV exposure and the wavelength range that causes the greatest breakdown on exposed coatings, in addition to water. These elements in combination best emulate the natural exterior exposed environment.

Gloss Retention (White)— QUV Exposure (ASTM D 4587)

Color Change (White)— QUV Exposure (ASTM D 4587) In addition to natural exposure, long-term protection of an exterior topcoat can be confirmed with a UV (ultra-violet) cabinet and an EMMAQUA device. Both devices introduce the UV exposure and the wavelength range that causes the greatest breakdown on exposed coatings, in addition to water. These elements in combination best emulate the natural exterior exposed environment.

Importance of Systems Unprimed 32 hrs. Alkyd 500 hrs. Epoxy 4,000 hrs. This slide clearly shows the protection afforded by primers, in contrast to an unprimed panel put in salt fog for only 32 hours. Notice the upgraded performance provided by a zinc-rich urethane over an alkyd shop primer. The hours listed for each generic type roughly indicate the amount of performance in salt fog hours one can expect it to protect. For example, most alkyd primers won’t provide satisfactory protection past 500 hours in salt fog, whereas a zinc-rich urethane still protects after 10,000 hrs. Point out the two areas of the panel: the scribe at the bottom which allows the salt solution to directly attack the steel panel and the plane, or unscribed area, where the intact coating’s barrier protection is evaluated. Unprimed 32 hrs. Alkyd 500 hrs. Epoxy 4,000 hrs. Zinc-Rich Urethane 10,000 hrs.

Utilizing Results Performance specification and minimum results based on both laboratory and natural exposures Key Criteria Color retention - Delta E (color space) Gloss Retention (change from standard) Chalking Adhesion (system must remain in place) Retain sample panels Product warranty required (outline acceptable ranges) Picture of a retained sample to compare original batch color to actual coated substrate. (Water tank in Hawaii after 10 years of exposure.)

CASE STUDIES EXTENDING PERFORMANCE WITH FEVE FLUOROPOLYMERS

Water Storage Tank Mt. Jackson, VA Finish Coat: FEVE Fluoropolymer Previous system had an adhesive coating system, in less than 10 years the system showed significant fading and the owner was not happy with the performance. The owner decided to go with an FEVE fluoropolymer system, as a fluid-applied option that would provide superior corrosion protection and exceptional color and gloss retention.

OBSERVATION DECK PORT CANVERAL, FL Finish Coat: FEVE Fluoropolymer With its bird’s-eye view of Port Canaveral, Florida, the outdoor observation deck on the top of Exploration Tower has visitors flocking to take in the scenic views of passing cruise ships and rocket launches from nearby Kennedy Space Center. To keep the viewing area looking its best for many years, the project’s designers specified a fluoropolymer coating system. “They were looking for long-term color and gloss retention. “Recoating the elevated steel would be incredibly difficult, so they wanted to avoid having to do maintenance painting for many, many years.” The entire coating system was shop-applied by the steel fabricator. “The arches above the observation deck were brought out to the site preassembled and lifted into place with a large crane. The four-coat system was spray-applied over steel that was prepared in accordance with SSPC-SP10/NACE No. 2 Near-White Metal Blast Cleaning. The complete system was an aromatic zinc-rich polyurethane, a water-based epoxy, an aliphatic Polyurethane, and a finish coat of fluoropolymer Finish Coat: FEVE Fluoropolymer

CAST IRON FAÇADE SALT LAKE CITY, UT Finish Coat: The 75-foot high by 140-foot long facade features cast iron colonnades with ornamental castings and a cornice section made of galvanized metal. The amount of craftsmanship and handiwork that goes into restoring cast iron architecture like this is unbelievable, so this project required high-performance coating systems. Pitted cast iron pieces were reconditioned using a surfacing epoxy and primed with a zinc-rich aromatic urethane. Structural steel used to secure cast iron components to the building was blast-cleaned and primed by the fabricator with a zinc-rich coating. The façade’s cornice section was prepared in accordance with SSPC-SP1 Solvent Cleaning. “They originally tried abrasive blasting, but the sheet metal was too thin so they used a chemical stripper on the metal and pressure-washed it. The cornice section above the window bays were galvanized metal that was 100 percent shop-applied. The section was primed with an epoxy, followed by a finish coat of FEVE high-solids fluoropolymer resin that offers outstanding color and gloss retention. Among the custom colors specified was an elegant gold accent, matched to simulate 24-karat gold leafing, in Fluoropolymer Metallic. The Fluoropolymer was then topcoated with a Metallic Clearcoat, a clear coat used to both enhance the finish and extend the long-term weathering qualities of metallic pigmented coatings. Structural steel for these sections was primed with a high-build epoxy. During the recoating, the façade was surrounded by scaffolding and enclosed to help control environmental conditions. Tie-coats, finish coats and the gold accent finishes were applied with brushes, rollers and sprayers to the cast iron columns and individual decorative castings that were then reassembled and attached by screws. Finish Coat: FEVE Fluoropolymer (Metallic)

High Rise—New York, NY 12+ years of Performance (2002) Finish Coat: FEVE Fluoropolymer (Metallic) Opened in 1929, this 40-story New York City landmark was designed by the architectural firm of Walker and Gillette and was owned and built by George Fuller. Building contains glorious art deco metal figures and decorative features in bronze and cast iron. In 2002, building owner recommended that the priceless art deco figures beneath the windows be cleaned, repainted and protected with Premier Finishes. (Left: 2002, Right: 2011) System: Primer: Zinc-Rich Urethane Intermediate: Aliphatic Polyurethane Finish: Fluoropolymer Metallic

Important Points UV light degrades coatings by activating free radicals in binder, pigments and additives. Various binders react differently to free radicals. Additives can also be used to limit their effect. Color and gloss retention depends on performance of binder, pigments and additives. High-performance coatings like FEVE Fluoropolymers, despite being more expensive, provide longer-term aesthetic performance and lower life-cycle cost. This presentation highlights two important points when selecting a topcoat for aesthetic reasons: 1. There are many things, such as generic type and quality of additives, that affect the performance of a coating. Just because a product identifies itself as a “polyurethane” doesn’t mean it offers equal color and gloss performance to other polyurethanes. 2. Like most things in life, “you get what you pay for”. Inexpensive topcoats offered by the manufacturer are that way for a reason. They usually contain less expensive additives and pigments, and the binder can also be modified to bring the cost down. Considering the cost of application, and reapplication, a higher performance topcoat that may cost a little more initially will have a lower life-cycle cost.

Thank you for your participation in today’s presentation. QUESTIONS?