Case Study: Eastman Chemical Company Fights CUI with VSC 1200

One of the costliest corrosion problems faced by the chemical processing and petroleum refining industries is corrosion under insulation (CUI). CUI affects both carbon steel and stainless steel equipment and has been recognized as a problem for many years. The American Petroleum Institute publishes recommended practice API 583, “Corrosion Under Insulation and Fireproofing” which provides information on the causes and mitigation of CUI. The National Association of Corrosion Engineers publishes SP0198, “Control of Corrosion Under Insulation and Fireproofing” which provides information on the use of coatings to prevent CUI. In both documents coatings play a major role in preventing CUI.

Like all its peer companies Eastman Chemical Company has experienced CUI of both stainless steel and carbon steel equipment. Recently Eastman began a program of CUI-related inspections and repairs to extend the life of several critical assets that operate under conditions that are conducive to CUI. Previous experience suggested that CUI was likely with an elevated temperature distillation column made of carbon steel. The column has been in service since the early 1980’s with an operating temperature that varies from about 100°C at the base to 80°C at the top.  Operating requirements prevented shutdown of the column so all coating and insulation work was completed while the column was in operation and the external surface was hot. When new, the equipment was painted with a red iron oxide primer and insulated with two inches of fiberglass blanket insulation. After more than 30 years of operation in an exposed outdoor location the insulation was removed to permit a thorough external inspection, found damage was repaired and a protective coating system and new thermal insulation was installed.

As expected, when the old insulation was removed, corrosion of the steel substrate was found.  It is very difficult to prevent the ingress of water through an aluminum jacket, particularly one that has many jacket penetrations – which is why corrosion to the shell occurred. Figure 1 shows typical corrosion damage found at an insulation support ring. Support rings are horizontal surfaces designed to provide vertical support for the thermal insulation.  In this case, the ring was welded directly to the shell, which allowed water to accumulate in the insulation on the topside of the ring, resulting in corrosion of the steel shell.

Historically, Eastman has used either epoxy phenolic or multi-polymeric coatings for CUI protection. In both cases the required surface preparation is abrasive blasting. Because this distillation column is in service, it was not possible to do abrasive blasting; instead an SP3 power tool-cleaned preparation was specified. VSC1100, a high-quality, high build surface tolerant aluminum epoxy mastic coating, was chosen for the first coat because of its outstanding corrosion resistance and excellent tolerance of marginally prepared surfaces. VSC1200, a top coat with Eastman Tetrashield™ protective resin systems, was chosen for the second coat because of its outstanding resistance to water permeation and excellent chemical resistance. Laboratory testing showed application of VSC1100 to a hot surface had no impact on the curing or properties of the coating.  The hot surface temperature did require the addition of a cure blocker to ensure proper film characteristics for the VSC1200 topcoat. Figure 2 shows the VSC1100 as applied, and Figure 3 shows the VSC1200 topcoat.

Figure 1. CUI damage at insulation support ring.

Figure 1

Figure 2. VSC1100 applied to marginally prepared steel substrate at about 80°C.

Figure 3. VSC1200 topcoat applied to the VSC1100 aluminum epoxy mastic at 80°C substrate temperature.

Figure 3

Extensive laboratory testing carried out during the development of both coatings showed they have individual characteristics that provide each with excellent properties that, when combined, produce a coating system with excellent corrosion resistance. The Tetrashield resin provides excellent resistance to water permeation and resistance to many aggressive chemicals. These characteristics make it very useful in moderate temperature CUI applications where an abrasive blast surface preparation is not possible and in situations where the equipment cannot be taken out of service.

Immersion grade coating systems are chosen for CUI applications because they may be exposed to hot, wet conditions for extended periods. The high build epoxy systems are only recommended for temperatures up to 60°C in NACE SP0198.  Between 60° and 150°C NACE recommends epoxy phenolic coatings which are considered immersion grade coatings.  However, in cases where the recommended abrasive blast cannot be done, the epoxy phenolic cannot be used. The system can bridge the temperature gap between 60° and 150°C given its good moisture permeation and corrosion resistance; however, it is not an immersion grade system and should not be chosen in situations where continuous hot immersion is possible. The design of the insulation system should be done with CUI resistance in mind to help the coating system function as intended. For the Eastman project, a moisture resistant insulation was chosen, along with an elastomeric jacket material that is adhesively sealed to itself and to the vessel being insulated as seen in Figure 4. This combination made it much less likely that water could get to and be held against the surface, thus reducing the need for moisture resistance in the coating system. The VSC1100/1200 system with its good moisture permeation and corrosion resistance is a good choice for moderate temperature applications when the substrate is corroded and abrasive blasting is not practical.

Figure 4

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Discussion of coatings selected for deck remediation where the decking has been exposed to Phenolic Foam Insulation (PFI).

History:

In 1991, the major industrial coatings manufacturers of the United States were contacted by Beazer East, Inc. through a consulting firm.  These coating manufacturers were presented with the problem of specifying a surface preparation and coating system to be applied over corrugated steel decking that had been in direct contact with, and/or corroded by, Phenolic insulation.  The coating had to be able to be applied to both painted steel and galvanized steel decking.

Problem:

Phenolic insulation exposed to humidity or direct moisture (such as roof leaking) creates sulphonic acid.  In a short amount of time, this sulphonic acid corrodes both standard painted deck as well as galvanized deck. It is important to note that the coatings used to paint corrugated decking are applied at a thickness of between one half and three quarters of one Mil DFT. That is less than one thousandth of an inch. A sheet of newspaper is three thousandths of an inch thick. The phenolic insulation also has a history of crumbling, and easily crushes when walked on, leaving a residue on the decking.  This residue is present regardless of whether the insulation has been crushed or not.

Discussion:

In order to have corrosion, three things are required, oxygen, moisture, and a catalyst.  In our case, the catalyst is the Phenolic insulation residue and the sulphonic acid.  In order to prevent corrosion in this application, we would need to remove all the residue, which is not practical.  The easiest way to prevent corrosion is to prevent moisture from coming in contact with the phonlic residue and the existing corrosion or steel by means of a high build barrier type coating.

Specification:

When developing a specification for surface preparation and coating selection, there are limitations to what surface preparations are available, possible, and practical.  When making a coatings selection there are also limitations as to the occupancy of the building and limitations of surface preparation, and the skill level of the applicators.  Any change made to the surface preparation will change the selection of the coatings system used.  When reviewing the possible surface preparations, we are limited in the sense that many of the industrial surface preparations, such as abrasive blasting or water washing, are not practical.  Regardless of what practical surface preparation is chosen, we know that corrosion and the sulphonic/ phenolic residue will remain on the remaining surfaces.  It is not practical to completely remove the residue or the corrosion as it would be less expensive to just remove and replace the deck.  For our surface preparation specification, we use the Steel Structures Painting Council SP-2 hand tool clean or SP-3 Power-tool clean.  The level of cleanliness for these specifications are the same, the difference is the methods used to reach the required level of cleanliness.

Examination:

After examining the profile of decking that had been corroded by sulphonic acid/phenolic residue; we found after cleaning, that the profile or depth of the corrosion ranged between two and eight thousandths of an inch (mils).  This meant that our minimum dry film thickness required to cover the deepest profile was at least nine (9) mils.  The profile of the corrosion directs us to a high build coating which is also surface tolerant given that corrosion will remain on the steel decking. This coating must be able to be applied to and adhere to existing coatings, without lifting, and adhere to galvanized decking.

Degrees of Damage:

It is not that the sulphonic acid is so damaging, it is that the insulation boards will hold around 10 times their weight in water allowing it to stay continuously wet and dissolve the deck.

This is typical of the damage, full, active corrosion from top(flange), down the slope(web) into the bottom(flute). The dust is mostly crushed insulation. The phenolic foam dust cannot be fully removed without washing it from the deck. The previous roof system was mechanically attached using screws that penetrate through the decking. In areas where the roof has had leaks, these fasteners/screws can be completely corroded through leaving the screw head and washer on top of the foam and the end of the screw falling into the building.

The beginning of stratified corrosion. Beyond this degree of corrosion a consultant would recommend either removal of the section of deck or preparing, coating and overlaying of the area

This section of decking has been completely corroded through. The section was prepared, coated and overlaid with new decking.

Selection:

Products such as acrylic primers or oil based (alkyds) primers cannot be used and have failed when used for several reasons:

-Acrylics (typically 35 to 50% volume solids*) meet neither the surface tolerant requirement nor have the ability to be applied in thicknesses greater than five (5) mils dry (DFT dry film thickness).

-Alkyds (typically 45 to 60% volume solids*) have limited surface tolerance but do not meet the high build thickness requirement. Also oil based coatings contain oxidizers which are the drying mechanism (along with solvent evaporation), these oxidizers continue to “dry” the coating until no oil remains, thus leaving a dry powder residue which has no barrier properties and will allow the deck to corrode again.  Oil based primers are typically applied between 2.5 and 4 mils DFT.

-Standard Epoxies (typically 60-75% volume solids*) can meet the surface tolerant requirement but not the film thickness requirement. Typically applied from 3 to5 mils DFT.

*Volume solids are the amount of liquid in the can that actually forms a solid film.  Any part of the coating that is not volume solids is solvent and needs to evaporate out of the coating to ensure proper curing. Only volume solids have film forming characteristics.

In all three of these cases, applying the coating at a greater film thickness than designed in the formulation process will cause solvent entrapment due to the low volume solids.  This will lead to continued corrosion because the film becomes very porous due to the solvent bubbles/blisters working their way to the top of the film.  A cross section of these films looks very much like Swiss cheese.  Epoxies can cause osmotic blistering as the uncured coating pulls moisture through the film and back down to the substrate (decking).

Conclusion

High Build Epoxy Mastics (75-100% volume solids). Epoxy Mastics, when formulated properly allow for surface tolerance, moisture impermeability, high volume solids, and high film build. Not all high build epoxy mastics are surface tolerant; many are formulated to be a build or mid-coat in a three coat system or as part of a lining system where chemical immersion will be the end application, requiring abrasive blasting and the removal of all contaminants to clean steel.  The coatings we have selected are formulated meeting our requirements and have been tested on steel decking that has been removed from buildings that have had Phenolic insulation on them.  The coatings that we have selected meet both the surface tolerant requirement and the high build requirement.

When deciding on a coating, we looked for surface tolerance moisture impermeability, adhesion, film thickness, and, specific to our application, ease of use.  For this application we had to keep in mind that the coatings would be applied by roofers and not professional painters.  In most cases, these roofers need to be taught not only how to prepare the decking, but the proper application of the coating, and the use of the spray equipment to apply the coating.  In consideration of the project limitations we look at how easily the coatings can be mixed together (how they “handle”), how easily and with what type of equipment they can be sprayed (standard airless or plural component), and the pot life or working time before the coating sets and cannot be used, and if there are any limitations due to weather/temperature.

The difference between the two coatings is more than simply a matter of odor.  The first epoxy recommended/used is Sigmacover 7428 ST ( Sigmacover 7428 ST  is discontinued now look at US Coatings DeckGrip 6120)  which is an 85% volume solids surface tolerant high build epoxy which is applied at 12-14 wet mils, and curing to between 10.2 and 11.9 mils.  As it is a high solids epoxy, there is odor from the 15% solvent and the inherent odor of the ingredients that make up this product.

The second coating that we recommended/use is Sigmacover CSF 5484 (CSF = Cold Solvent Free,( Sigmacover 5484 ST  is discontinued now look at US Coatings DeckGrip 6250) meaning it will cure at ambient temperatures and is solvent free). The DeckGrip is a 100% volume solids, low-odor high build surface tolerant epoxy which is applied at 14 to 16 wet mils curing to 14-16 dry mils. That the coating is solvent free is not the only reason that it is low odor, the ingredients of the product are very low odor in and of themselves aiding in the “low odor” facet of this product. It is erroneous to assume that all 100% solids epoxies are low odor. The GripLine family of products are used extensively as tank linings ranging from potable water to refined crude oil products.  It is because there is very little odor that we tested and recommended this product as it met all of the requirements.  The DeckGrip has been used for the past several years on all facilities handling Pharmaceutical, Produce, Brewery, and Grocery, Hospitals, and office building/complexes (including the Youngstown, OH Postal Clearing Center) where both odor and airborne solvents are an issue.  It would be easier for us to use the CSF 5484 or CSF family of products on all Phenolic projects but the cost is almost twice that of the standard epoxy, and in a number of cases, this low odor product is not necessary.

Coatings testing: Both of these coatings were applied to samples of decking removed from buildings that were being remidiated.  The panels were separated by degree of corrosion ranging from very little corrosion to being corroded to the point at which the decking would be replaced rather than coated. One half of each panel was hand prepared as per SSPC- SP-2 and the two coatings were applied at the recommended film thickness.  The panels were then laboratory tested in 100% condensing humidity.  After 2000 hours, the panels showed no blistering or delamination (loss of adhesion) or other failure.

It is important to note that in 14 years and over 3500 Phenolic deck remediation projects no system that we have recommended has failed.  In those 14 years, we have supplied over 700,000 gallons of epoxies to projects involving deck remediation where the deck was exposed to and was in direct or indirect contact with phenolic insulation.

The John’s Manville projects that we have completed, the Sigma Coatings/US Coatings have been specified by architects, engineers and roof consultants.  These specifiers consider the products, application, performance and the field personnel put in place to aid the contractor in project start up.  US Coatings as a company gives a warrantee against active corrosion on every project that is completed using their coatings.

Application and repair of Roof Decking

A power broom fitted with a 100% wire brush head is used to prepare the deck to what approximates an SSPC-SP-2/3 level of cleanliness.

The deck is blown clean after power brooming. This cleans the dust and debris out of the bottom of the flutes. The phenolic foam dust is too fine to be efficiently vacuumed as it quickly clogs vacuum filters.

The airless sprayer is fitted with a dual spray nozzle which allows the web-flute-flange to all be coated at the same time including the web that is facing away from the applicator. Using the DSN greatly increases the production rate of application and reduces the amount of wasted paint caused by making too many overlaps or going back to cover missed areas.

An applicator should be able to properly coat around one full square of roof area per minute which represents 100 sq/ft of floor area and is actually 135 sq/ft of coated surface area.

The new roof insulation is immediately laid into the wet DeckGrip as the roof area is coated.

The finished application at 14-16 wet MILS. No, Yogi Bear was not taking the pictures….

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VSC 1200: An advanced polyurethane industrial maintenance coating with superior long term performance

US Coatings is excited to introduce a new 2K polyurethane finish and surface-tolerant epoxy mastic system that outperforms competing systems in almost every way—at no added cost.

The VSC 1200 Topcoat and VSC 1100 Primer are more durable, sustainable and productive on the job. This improved performance is thanks to the groundbreaking Tetrashield™ protective resin developed by Eastman Chemical Company.

High-performance industrial maintenance coating system

VSC 1200 Topcoat and VSC 1100 Primer represent the next-generation of heavy-duty industrial maintenance coatings. Owners will like the system’s superior asset protection for the price while contractors will enjoy the ease of use of this system leading to a lower overall cost of ownership for industrial asset owners. The performance-driven marriage of the VSC 1100 primer and the Tetrashield-enhanced VSC 1200 finish is a winning combination in the fight against corrosion with an attractive maintenance price tag.

VSC 1200 Topcoat

VSC 1200 Topcoat is a hard, tough and extremely durable two-part (4:1) solvent-based topcoat using Eastman Chemical Company’s Tetrashield™ protective resin. Tetrashield ™ is the breakthrough at the heart of this heavy-duty industrial maintenance coating that provides the following advantages:

• Consistent film build and easier application.
• Exceptional adhesion.
• Outstanding weathering, including superior gloss and color retention over standard acrylic-polyurethanes.
• Contractor-friendly with longer pot life and shorter dry time compared to traditional acrylic coating systems.
• Wide latitude application conditions with long recoat time, fast dry to the touch and faster through cure even at lower temperatures.
• Environmentally-friendly formula uses high-solids formulation that requires no thinning solvents, thus reducing VOC emissions.

VSC 1100 Primer

VSC 1100 Primer is a two-part (4:1) epoxy mastic exhibiting outstanding wetting properties (for less than ideal surface preparation) and excellent film hardness for long term durability. Performance testing shows that it vastly outperforms competing primers. It boasts the following key qualities:

• Superior adhesion to a wide range of surfaces, including steel, aluminum and concrete.
• Exceptional corrosion resistance.
• Superior wetting properties to perform even on marginally-prepared surfaces.
• Lower-temperature cure.
• Accepts a wide variety of weathering or chemical-resistant finishes.

Eastman Tetrashield™: Breakthrough protective resin

With the advanced Tetrashield™ protective resin at its core, VSC 1200 Topcoat provides more flexibility in application while providing superior performance in harsh environments over the long term.

The resin responsible for the superior performance has its origins elsewhere in the chemical industry. Before there was Tetrashield™, there was Tritan™—a BPA-free TMCD polyester Eastman developed that offered enhanced clarity, toughness, chemical resistance and impact strength for products used in medical, household and retail applications.

Eastman chemists then developed the Tetrashield™ resin to provide in the coatings industry the benefits that Tritan™ offered for consumer products. The result is a heavy-duty industrial maintenance coating that exhibits premium performance without a premium price. Coating projects are shorter, the coating dries faster and critical assets are put back in service sooner—and that keeps costs in check.

Find out more about how industrial coating projects can be made easier by reading our guide to a painless painting project. If you want to have a conversation about an upcoming job and whether the VSC 1200 Topcoat / 1100 Primer system is right for your site, let’s talk.

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Selecting the right coating – the basic questions

If one coating could do everything, coating selection would be limited to color and gloss choices and specification writing would be relatively simple. Since that magic coating does not yet exist, we are left with hundreds of possible choices.

Many popular coatings can perform multiple functions. But real-world situations often demand more specific performance requirements. Effective coating selection should be based on the demands of the project, such as performance, application, budget and other requirements.

There are some basic questions that the specifier, engineer or owner need to answer to narrow the choices and find the best option.

4 questions to ask when selecting an industrial coating

Questions to ask when selecting an industrial coating

What is being coated and why?

The answer to this question indicates the scope of the project and the expectations of the owner. It may sound basic, but answers can be surprisingly deceptive.

The reason for coating something like a vessel could simply be the company CEO is going to visit it next month. Appearance then means everything and no one is really interested in the benefits of a 25-year corrosion resistant coating system.

What exposure will the item see?

This is perhaps the real “meat and potatoes” question that tells us what environmental conditions the application will regularly face. There are many parts to this question which include:

1. Is the item exposed to the weather or wet interior environments like food process areas?
2. Are there any elevated temperature conditions?
3. Are there any harsh chemical fumes or potential chemical spills?
4. Will the coating be covered by insulation?
5. Will there be any thermal cycling/shock?
6. How frequent will the coating be cleaned and with what chemicals?
7. Will the coating experience any abrasion? What type (cutting or small particulate)?
8. What is the existing condition of the substrate (new steel, contaminated steel, rusted steel, old coatings)?
9. What is the condition of existing coatings?

How, when and where will the item be painted?

Answering this question will define the logistics of the painting project — whether applied at the shop, in the field or at an operating plant.

The coating may need to withstand early rain exposure or cold temperature cure. Certain coating systems will handle shop application better than others and will likely involve less shipping damage.

If spraying the coating is not possible due to issues like overspray problems, a brushed or rolled coating must be selected. If the speed of completion of the project is critical, fast dry/cure products will be preferable.

In many operating plants, open abrasive blasting may not be possible, so products with surface tolerant properties must be selected. And while these products are technologically advanced, those that require higher degrees of cleanliness are preferred for longer service lives.

What are the owner’s expectation in terms of service life?

At face value, one would think that the answer should be “as long as possible,” but this is not always the case, especially with limited budgets.

In the earlier case where the CEO was to visit the plant, giving the vessel a fresh look could be done rather inexpensively using a coating system with a minimal design life, especially if the vessel is to be dismantled in five years.

On the other hand, it would make sense to select a long-term service life system for an elevated water tank with a design life of 90 years, especially if it has the local high school mascot painted on it. But the longer service life systems will cost more in surface preparation and application.

Don’t guess, be certain

In the end, it is best to discuss your coating needs with a coating professional who will walk you through the basic analysis outlined here and match the right coating system for your specific set of circumstances and expectations of service life.

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“The Top Two Considerations of Writing Coating Specifications: Performance-Based versus Specific Named Products”   

A coating specification serves many purposes.

In its basic use, it provides a roadmap for the proper installation of a coating system. Any number of painting standards are often referenced to provide the applicator or end user proper guidelines for carrying out the specified surface preparation and proper application of the specified coating or coating system.  The specification as written already assumes that the coatings specified are suitable for the exposure and will meet the expectations of the owner.

Unfortunately; all too often, specifications are poorly written, can cause ambiguities, fail to account for problems that may come up (example: failing to specify cold-cure products during winter painting) and probably the most problematic (to the end customer) specifying the wrong products.  Those are doomed to early failure.  If the products that are specified are wrong for the application; the rest of the specification is moot.

This article will discuss two commonly used types of coating specifications; one that uses “performance-based” requirements and the other simply calls out “specific named products”.  The assumption (for this article) is that the specification as written will indeed handle the exposure and will meet the owner’s needs and expectations.  A separate article will discuss how to select the right coating system.

Performance Based Specifications

These specifications do not call our specific products by name, but rather list a series of performance requirements (minimum performance) to which the candidate system must comply. It may call out a more general performance requirement or even reference independent (3^rd party) specifications such as SSPC (Society for Protective Coatings) http://www.sspc.org/ or MPI (Master Painters Institute) http://www.paintinfo.com/index.asp or others.  Often, each coating (primer, intermediate coat and/or finish) has specific performance requirements listed.

Well written specifications call out specific requirements that will satisfy the needs of the project.  For example, it may call out a certain corrosion resistance for the primer tested to say ASTM B117 (commonly known as the Salt Fog test).  It should spell out the extent of the test (say 500 hours) and then spell out the minimum performance requirement (say no more than 2 mm undercutting at the scribe with no plane blistering or rusting).  A poorly written specification will simply say “tested to 500 hours in Salt Fog cabinet” without any performance requirement.  Testing without performance requirements is meaningless.  Any product can be “tested”.

A finish coating may have performance requirements written around weathering resistance (gloss and color retention) or abrasion/scratch resistance.  In these cases, certain test standards are referenced and minimum performance requirements are defined. Examples of some of the common tests are depicted in the chart below.

A couple words of caution when using or interpreting performance-based specifications:

1. Be careful that the performance test used actually matches how the coating will be used. For example it makes little sense to call out a weathering performance on a primer that will be topcoated.  Likewise, calling out a Salt Fog test solely on the finish coat makes no sense.  The test must match the intended use of the specific coating or coating system.
2. Be careful when interpreting submitted coatings for consideration that are “close” to meeting the specification. There are countless examples of coatings that “miss” meeting the specification because of a too strict interpretation of the requirement.  For example:  When comparing two finish coats that have abrasion resistant numbers of 115 mg loss versus 125 mg loss and the specification calls out no more than 120 mg loss (more loss is less abrasion resistance), the one with 125 mg loss does not meet the specification.  From a practical standpoint these two finishes have essentially the same abrasion resistance and their reported abrasion numbers are certainly within the tolerance of the test method. Yet, a perfectly acceptable coating would be disqualified based on a strict interpretation of the specification.  So, a specifier should have a very good working knowledge of performance testing, their meaning, and the significance of reported values when qualifying coatings for use.

Shown below is a chart with some commonly used performance-based standards for primers and finishes used for atmospheric exposure.  This is by no means a complete list.  These referenced methods may change based on end use, such as tank linings, high heat coatings, etc.

Primers

Finishes

Specific Named Products

One of the advantages of specifically named products in a specification is that the specifier (engineer or owner) has already determined that the products listed will satisfy the intent of the specification and the needs of the owner.  These types of specifications will often list competitive products that may be quite similar to each other (equals) or may in fact be quite different from each other.  While the coatings may perform in service similarly, one coating system may have faster dry times or low temperature cure capability that might be favored for a specific set of circumstances.  It is then left up to the contractor to choose the system that best fits the application needs.

In the end, there are no right or wrong specifications.  There are good specs and bad ones and everything in between.  The best ones are those that are well written with minimal ambiguities and fulfill the needs of the owner for the anticipated exposure and the owner’s expectations.

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Zinc primers vs. galvanizing, the age-old debate

Inorganic zinc vs. galvanized coating applications

The following information was derived from the NACE Publication; “Corrosion Prevention by Protective Coatings” by Charles Munger; p: 153.

There is an age-old debate regarding using inorganic zinc primers versus galvanizing steel for protection against corrosion in exterior environments.

Inorganic zinc coatings contain metal, but they’re considered a silicate coating rather than a metallic coating like galvanized zinc. Galvanized coatings bond to the application’s surface with an amalgam of zinc and iron, while inorganic zinc coatings use iron and silica.

Inorganic zinc coatings are made up of individual zinc particles surrounded and interlocked by a zinc-silicate matrix that is only reactive to strong acids or alkalis, giving it a long lifespan under most environmental conditions. Galvanized zinc coatings are much more reactive to acids in the atmosphere, generally causing a briefer lifespan.

Studies found hot dip galvanized panels exposed to two years of tidal conditions were almost completely broken down by pinpoint rust. The panels coated with 3 mils of an inorganic zinc coating showed no substantial corrosion.

Inorganic zinc coatings are ideal for industries like marine operations, because they can provide protection with only a single thin application that’s less electrically conductive than galvanized zinc. The rock-like matrix of zinc silicates makes these coatings abrasion resistant, while galvanized coatings have a more malleable surface.

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Comparing and testing generic topcoats for exterior use

One of the important factors a buyer considers during the paint buying process is how well topcoats perform during their service.

Also known as weathering finishes, these coatings are designed for ultraviolet (UV) exposure during exterior use. They’re common in any industry that requires equipment or structures to be used or kept outdoors. Topcoats are the first line of defense against the elements, providing protection to intermediate coats which are designed to protect primers.

And it’s important to note right away that there’s no such thing as a coating that doesn’t weather. All coatings fade and break down eventually. With a greater understanding of topcoat formulations and quality testing methods, you’re empowered to make the choice that offers the best protection for your critical assets.

Accelerated weathering testing

In these tests, UV and moisture exposure is simulated in controlled settings over abbreviated time frames to judge how well coatings stand up to the elements. This is a preferred method for testing and comparing weathering finishes because it’s impractical to rely on real-time field tests that would take years to complete.

However, accelerated weathering testing is an imperfect method that requires strict controls and an understanding that actual results may vary in the field. Consider these practical issues:

• The UV lamps used to simulate sunlight in these tests emit radiation only in a very narrow bandwidth compared to the broad-spectrum UV radiation produced by the sun.
• Proper testing in controlled conditions cannot replicate or predict the diversity of ever-changing operating conditions in the field.
• There’s no accurate way to translate results from accelerated weathering testing to actual useful service lives for coatings in the field. The testing should only be used to compare coatings against one another in similar conditions.

Comparing coating formulations

Tests conducted on weathering finishes are designed to shed light on a few different things, such as:

• Resin quality – Resins are key components in coatings because they form the matrices that hold color pigments in place. When testing coatings to judge the quality of their resins, it’s best to use white or light-colored formulas that lack color pigments. That’s because differing color pigments degrade at differing rates, and that could skew the results of tests targeting resins.
• Color fastness – Not all pigments are created equal—even like-colored pigments. For example, the red pigments used to color a muscle car are of far higher quality than those used in other, shorter-term applications. When testing for color fastness, choose formulations with similar resin quality so that resin degradation doesn’t interfere with pigments.
• Gloss retention – When comparing the rate at which gloss loss occurs in a coating, it’s critical that the angles to which lamps are set remain constant. Differing angles alter the way light impacts a painted surface, and results will not be reliable.

It’s important to maintain other constants in tests, too, like film thickness, application method, curing conditions, testing exposure cycles and testing surface preparation. Ignoring experimental controls allows too many variables to interfere with test results.

Performance benchmarks

The Society for Protective Coatings’ (SSPC) standard for two-component weatherable aliphatic polyurethane coatings (SSPC Paint 36) defines three performance levels for weathering finishes.

Level 1 finishes are rated based on 500-hour exposures during accelerated weathering tests. Level 2 finishes are rated based on 1,000-hour tests. Level 3 finishes are rated based on 2,000-hour tests.

Alkyds or oil-based coatings are typically tested in the 250 – 1,000 hour range; most of these coatings sustain significant gloss loss at the high end of this range.

Epoxies lose gloss quickly and begin to chalk after a couple hundred hours of exposure.

Acrylic formulations can vary widely, but they typically hold gloss for between 1,000 and 2,000 hours.

Polyurethanes are even more variable in formulation than acrylics and are commonly tested for several thousand hours. Polyurethane clear coats care often tested into the 5,000 hour range.

Siloxanes and fluorourethanes known as “ultra-weatherables” have shown impressive gloss retention even after 9,000 hours of accelerated weathering testing.

Comparing US Coatings finishes

US Coatings offers many weathering finishes. Buyers need to carefully consider all aspects of an asset or structure prior to choosing a weathering finish, including:

• The intended use of the asset and whether such a finish is even appropriate.
• Whether the aesthetic appeal of an asset is important to its end use.
• Whether a such a finish is being used in conjunction with other coatings or asset protection systems.
• How frequently you expect to re-coat the asset.

Use the chart below to determine which US Coatings product is the best match for your exposed assets:

We’re here to help you answer any questions you may have. If you want to talk through your options further, let’s talk. You can also explore our products in greater detail by downloading our product data sheets here.

Choosing the right weathering finish is just one step in assuring your next painting project goes off smoothly. In this guide, we take you through all the elements of a productive —and painless— industrial painting program.

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Recoating aged and weathered coatings when proper prep is not always an option.

MasticGrip 2500 is a surface tolerant, aluminum flake filled, mastic epoxy which can act as primer or finish.

MasticGrip 2500  is an aluminum pigmented, low-stress, high-solids mastic with outstanding performance properties and offers . It has unique properties over conventional coatings because it wets out existing rust down to the steel substrate. MasticGrip 2500 coating in a number of industrial markets. Today it continues to provide unmatched levels of barrier protection and corrosion resistance over existing finishes and rusted steel; or is suitable for hand or power tool cleaned surfaces.

MasticGrip 2500: What is the Labyrinth Effect?

The Labyrinth effect essentially creates complex maze for moisture to not easily penetrate the coating. This is important because the rate of osmosis is a critical component to premature coating failure. MasticGrip 2500 utilizes aluminum flakes of various sizes which acts similar to a coat of armor for your substrate. The protection is effective against everyday abuse from UV, water, and chemicals.

Why use MasticGrip 2500 as a “everywhere” primer?

The low viscosity formulation enables it to wet out and penetrate rust down to the substrate, yet it’s high solids allows it to bond to a variety of aged coatings without crazing or lifting. In short, MasticGrip 2500 is the most dependable, robust protection for maintenance painting available. It’s the best primer choice for aged, weathered coatings that can’t be mechanically abraded. This primer/finish is the perfect solution for owner you would like to get five to ten more years out of an asset before a complete repaint down to bare steel.

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US Coatings offers prefabricated hazardous material storage buildings

US Coatings is enhancing customers’ ability to comply with hazardous material storage and containment requirements by offering prefabricated hazardous material storage buildings.

Industrial firms rely on these structures to safely store dangerous corrosive, flammable, combustible or other hazardous materials that they must keep in or near their facilities.

US Coatings offers a wide range of free-standing, relocatable prefabricated hazardous material storage buildings to meet any facility’s need. Structures available include:

• Non-combustible steel construction – Designed to store flammable or combustible liquids and other hazardous materials, these structures feature exterior weatherproof unitized non-combustible steel construction made with welded structural and heavy-gauge steel sheets.
• Two-hour fire-rated uni-directional – These structures are designed to store flammable, combustible, corrosive and poisonous materials and incorporate weatherproof two-hour fire-rated non-combustible heavy-gauge steel construction. The design includes layers of UL-Classified fire-resistant gypsum wallboard between the exterior steel and interior galvannealed steel sheets.
• Two-hour fire-rated bi-directional – This model safely contains drums, compressed gas cylinders, bottles and other hazardous material containers. It features weatherproof bi-directional two-hour fire-rated non-combustible heavy-gauge steel construction and includes layers of fire-resistant gypsum wallboard, insulation and galvannealed interior and exterior steel sheets. The structure meets UL Fire Resistance Rating U425.
• Four-hour fire-rated bi-directional – This structure is designed to contain drums, totes, compressed gas cylinders, bottles or other hazardous material containers when they must be stored very close to other buildings or within a larger structure. It meets UL Fire Resistance Rating U490 and features bi-directional four-hour fire-rated non-combustible heavy-gauge steel construction with insulation and two layers of UL-Classified Ultracode fire-resistant gypsum wallboard. Exterior surfaces are made of corrosion-resistant galvannealed steel sheets.

Additional standard features

All prefabricated hazardous material storage buildings we offer also come with the following features:

• Screened air inlet vents with UL-Classified three-hour fire-rated dampers.
• Open channel building base to allow for under-building inspections and for forklift and crane sling transit.
• Internal spill containment capacity of 30 percent of the total storage capacity.
• Hold-down brackets to bolt structures to foundations to resist seismic and wind loads.
• Static ground system including an exterior grounding connection, grounding rod, copper conductor and grounding lugs.
• DOT hazard placard.

All buildings are Factory Mutual-approved and labeled and meet all state and municipal building code requirements.

Customize your prefabricated hazardous material storage building

We know one size doesn’t fit all. That’s why we offer customization options for customers whose unique hazardous material storage needs require individual solutions.

Using modular construction, we build units up to ten feet tall and offer widths of 6 – 14 feet in two-foot increments. We can also vary the lengths of your structure, starting at 8 feet long and topping out at 52 feet, also in two-foot increments.

Optional temperature control systems and explosion relief vents that comply with NFPA 68 are also available on all US Coatings prefabricated hazardous material storage buildings.

Request a consultation

If you’re facing a hazardous material storage requirement, we want to guide you to the solution that best fits your need. Let’s talk — together, we’ll identify the building and accessories that ensure your hazardous materials are kept secure and your personnel and assets are protected.

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Why warehouse floor coatings are more than just paint

Compared to other equipment and capabilities necessary in productive warehouses or similar settings, the industrial paint chosen to coat a concrete floor never tops anyone’s list.

But warehouse floor coatings are critical to safe, efficient operations because they can reduce slip and trip hazards, protect concrete from harmful spills and heavy abuse and increase an operation’s efficiency.

At best, underestimating the necessity of the right warehouse floor coating can hold an operation back from running at peak efficiency. At worst, it puts employees and assets at risk and firms on the hook.

Enhance safety, efficiency and aesthetics with warehouse floor coatings

In settings where heavy shelves and forklifts are used, the right warehouse floor coating can protect concrete from cracking and chipping as well as the harmful effects of spilled chemicals. Coatings also protect people. Workers can move more safely on floor coatings engineered to resist slips and trips.

While it may seem frivolous to labor over what color to paint a floor, the right color does more for a space than meets the eye:

• Spilled chemicals can be located and cleaned more easily when they contrast with the color of a floor coating. Differing floor coating colors can also separate sectors of a warehouse. This increases efficiency and reduces the risk of confusion and accidents.
• Utility bills in warehouses add up. But the right warehouse floor coating can reflect light, keeping spaces more brightly lit. High-gloss coatings can reduce the cost to light a space or lead to the reduction in amount of lights used.
• Aesthetics do matter. While a floor’s coating can add value in terms of safety, efficiency and asset protection, they’re also more pleasing to look at. Certain colors can even improve workers’ moods.

Comparing coating systems

The advantages and disadvantages of the many available coating systems mean decision makers must assess the work done in their spaces, the safety concerns present in those settings, their project budget and time constraints. Here’s a quick roundup of warehouse floor coating systems:

• MMA – Low-glare Methyl Methacrylate (MMA) systems are resistant to some acids, alkalis and solvents and boast a fast cure time—you can walk on an MMA-coated surface in less than two hours. MMA can be applied at lower temperatures, can withstand elevated temperatures and has a much higher dry film thickness (DFT) than other systems, making it resistant to scratching. But floor preparation cannot be overlooked as MMA systems don’t bond as well to substrates compared to other options. Good ventilation is required when applying odorous MMA coats. MMA systems require as many as four coats and are costlier compared to other systems.
• Epoxy and urethane – These systems also resist chemicals well and boast high hardness. Their dry film thickness is on par with other coatings systems, require three coats and are among the less costly alternatives. But these systems do not cure quickly. The walk-on time of 24 hours is among the longest of the available systems; because each coat takes longer to cure, the total project time takes nearly two days.
• 100% solids epoxy – These systems stand up to abrasion and chemical spills and can be applied to floors as part of a multi-part system or on their own. Because these coatings are 100% solids, their wet film thickness and dry film thickness are identical. That means no thickness is lost due to evaporation of harmful volatile organic compounds (VOCs). For this reason, 100% solids epoxy coatings are safer to use. They’re also the cheapest option, but they do not cure quickly —walk-on time is up to 24 hours.
• Polyaspartic – This hybrid system is an offshoot of epoxy and urethane systems that offers the advantages in a single coating what two coatings of epoxy and urethane systems can muster. Polyaspartic formulations can be manipulated to allow for curing times that suit individual projects and can be applied at temperatures well below freezing. Walk-on time is just four hours and polyaspartics are safer to use due to only moderate odors. These systems are costlier than epoxy / urethane and 100% solids systems but offer better flexibility compared to the other options.

US Coatings systems suit various needs

No industrial setting is identical, so one coating type certainly doesn’t fit all settings. That’s why US Coatings offers a range of floor coating options made to suit your individual needs.

GripCrete 200 SL – This 100% solids flooring epoxy is recommended in interior spaces where abrasion resistance or chemical protection is desired, including warehouses, service centers and commercial buildings. It can be used alone or in a multi-coat system.

GripCrete 200 SL can be applied directly to concrete but the risk outgassing / pinholing is reduced if the surface is primed. See additional GripCrete 200 SL specs here.

GripCrete 1750 MVE – MVE stands for moisture vapor emission. This low-odor, low-VOC, 100% solids concrete primer / sealer minimizes outgassing and moisture vapor transmission. GripCrete 1750 MVE is suitable for use as a primer in confined spaces and in underground or above-ground concrete coating applications. It can be applied to damp concrete.

GripCrete 1750 MVE is prone to chalking and ambering under sunlight in humid conditions; urethane or polyaspartic topcoats (such as GripCrete 200 SL or GripCrete 9000 PA) are recommended to prevent epoxy erosion and to retain color.

GripCrete 9000 PA – PA stands for polyaspartic. This next-generation coating is designed for a wide range of interior and exterior applications, including in warehouses, factories, chemical processing plants, stadiums and institutional buildings like hospitals and schools. It can also serve as a topcoat over other US Coatings floor systems. GripCrete 9000 PA is fast curing and UV-stable.

Polyaspartic coatings add greater value because they achieve in a single application the benefits of an epoxy and urethane system. As project timelines and budgets constrict, a polyaspartic warehouse floor coating could be the option that returns industrial spaces to service faster while keeping workers safe.

Thinking strategically about your warehouse floor coating can raise many questions, so contact us and we’ll help guide you through choosing the coating that best suits your space and developing a coatings maintenance plan. To get additional information about the products we offer, consult our product catalog.

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