NEWS ALERT: Three Cortec® Coating FAQs to Learn From

Do you ever have questions about good surface prep and coating adhesion when working with direct-to-metal coatings? Cortec’s Technical Service Manager, Rick Shannon, recently shed light on some frequently asked questions (FAQs) that come up when talking with Cortec® Coatings users.

1. Do I Need to Remove Cortec® VpCI®-41x Series Cleaners Before Coating?

If a sandblasted metal surface is going to sit exposed at least 24 hours before painting, it should be cleaned with a VpCI®-41x Series cleaner to remove grit and grime and inhibit flash rust. Since cleaners such as VpCI®– 414 and VpCI®-416 contain flash rust inhibitors that temporarily adsorb on the metal surface, the question arises of whether the cleaner itself needs to be rinsed off, as well, to ensure good coating adhesion.

The answer depends on how the cleaner was applied and how it has dried. Typically, Rick would recommend rinsing off the VpCI®-41x Series cleaner before painting, especially in areas where the wash water has pooled. However, if the VpCI® cleaner was applied by power-washing and has dried completely without pooling, adhesion should not be an issue, and the VpCI®-41x Series may not need to be rinsed off at all.

2. How Soon Can I Apply a Second Coating of CorrVerter®?

Another common question concerns recoat time. This is important because not waiting long enough for each coat of paint to dry before applying the next one can have a serious impact on adhesion.

In the case of CorrVerter® Rust Converting Primer, Cortec® recommends applying a second coat only after the first is dry to touch. Practically speaking, this often balances out to at least six to eight hours depending on the location and time of year. For instance, in the middle of July in the Northern Hemisphere, CorrVerter® may be ready to recoat in just three hours because the heat dries it out so quickly. But in late autumn as the temperatures fall, it may be necessary to wait overnight to get a full cure.

For any water-based coating, cooler temperatures greatly extend the recommended recoat time because water evaporation rates slow down. In fact, a cool, humid day could double recoat time. If painters have any question of whether a coating is ready to recoat, Rick recommends waiting overnight before applying the second coat. If for some reason it is not possible to wait, he suggests doing a coating adhesion test or solvent rub to see if the coating has cured.

3. How Long Can I Wait to Recoat?

On the other end of the spectrum is the issue of how long is too long to wait before recoating. Rick shared that for some Cortec® Coatings, recoating can wait indefinitely. Coatings such as EcoShield® VpCI®-386 or CorrVerter® can be recoated even a year later as long as the surface is clean. Other Cortec® Coatings, such as VpCI®-395 and VpCI®-396, cannot wait too long before recoating because their resins get much harder. If more than 72 hours have passed since applying these two coatings, the painter will need to scuff the surface before recoating to improve adhesion.

How to Make Use of FAQs

Many variables enter into the equation for each FAQ, and the answers are not always exactly the same. However, they provide a general rule of thumb on how to work with surface prep and coating dry time. The best way to make use of these FAQs is to use a healthy dose of common sense to apply the advice to each unique case. If uncertainty about a particular application still lingers, you can always contact Cortec® Technical Services for further help. Perhaps your own inquiry will even make it on a future list of FAQs!

Keywords: Coating FAQs, Cortec Coatings, coating adhesion, good surface prep, rust converting primer, how soon can I apply a second coating, how long can I wait to recoat, coating adhesion test, solvent rub test, Cortec

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PRESS RELEASE: EcoAir® Biobased Outdoor Coating: Seeking Renewability and Rust Prevention in Remote Locations

No matter how technologically advanced today’s society is, corrosion remains a fact of life. Manufacturers and maintenance crews continue to battle rust on metal components, equipment, and structures. While countless rust preventatives exist, Cortec’s EcoAir Biobased Outdoor Coating® powered by Nano VpCI® is one approach to corrosion protection that specifically caters to renewability and worker convenience concerns for those in remote or difficult-to-access areas.

Wet Film Corrosion Inhibitor

EcoAir® Biobased Outdoor Coating powered by Nano VpCI® is a biobased temporary coating designed for severe marine and high humidity conditions. It leaves behind an oily protective film that does not dry and is temperature stable to 180 °F (82 °C). It can be used to spray a quick layer of rust prevention on practically any metal part that needs protection: nuts and bolts, spare car parts, or other exposed metal surfaces. It is also great for quick temporary touchup on equipment where chipped paint cannot be immediately restored.

Rust Prevention with Renewable Content

A key feature of EcoAir® Biobased Outdoor Coating powered by Nano VpCI® is that it contains 65% USDA certified biobased content. At this percentage, it is also a qualified product under the mandatory federal purchasing initiative of the USDA BioPreferred® Program,* which requires federal agencies and contractors to give purchasing preference to products with a minimum level of biobased content in 139 product categories. For those who like Cortec’s CorShield® VpCI®-369 but need a biobased alternative, EcoAir® Biobased Outdoor Coating is a great substitute.

Convenient Coating Application

Another defining characteristic of EcoAir® Biobased Outdoor Coating is its packaging. EcoAir® Biobased Outdoor Coating comes in EcoAir® bag-on-valve (BOV) spray cans powered by compressed air rather than traditional chemical propellants. When the can is empty, the inside pouch can be thrown away and the can recycled.

Such packaging offers great convenience and portability. For example, workers doing MRO (maintenance, repair, operations) tasks on a rooftop unit may have to climb a ladder or steep stairway to reach the work area. While it would be impractical if not impossible to drag an air compressor and spray equipment up to the top of the roof to spray-apply a coating, it is easy to grab a can of EcoAir® Biobased Outdoor Coating and do a quick application wherever corrosion protection is needed.

Offshore platforms or other remote worksites are also great candidates for EcoAir® Biobased Outdoor Coating. It is much easier to bring along a spray can of rust preventative coating than to haul an entire drum of coating—not to mention spray equipment that poses trip hazards. EcoAir® Biobased Outdoor Coating is also much easier and safer to store onsite than traditional aerosols—especially in high-risk environments like the oil and gas industry—because it is classified as nonflammable (flash point: 257 °F [125 °C]).

The Battle Continues for Sustainable Rust Prevention

Corrosion never dies, but neither does Cortec® stop looking for ways to bring user-friendly, sustainable features to the battle. EcoAir® Biobased Outdoor Coating is one example of a convenient solution for environmentally conscious end-users or those simply looking for a way to comply with biobased purchasing mandates. Contact Cortec® to learn more about EcoAir® Biobased Outdoor Coating:

*For more information, go to

Keywords: biobased coating, rust prevention, corrosion protection, rust prevention with renewable content, BioPreferred, USDA certified biobased, mandatory federal purchasing, EcoAir Biobased Outdoor Coating, MRO coating, Cortec

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NEWS ALERT: Have You Ever Considered Using VpCI®-369 for Dip Tanks?

VpCI®-369 is one of Cortec’s most popular wet film corrosion inhibitors, used in spray applications around the world. But have you ever considered using VpCI®-369 for dip tanks? One major global equipment manufacturer decided to do so when an emergency shortage of their standard rust preventative (RP) sent them looking for a different product. A custom version of VpCI®-369 was an almost seamless substitute that mirrored the qualities of their previous RP used in both spray and dip applications. Their story of adapting it to a dip tank application offers inspiration for other manufacturers who may want to use the same method of corrosion protection for their service parts.

History of Use

VpCI®-369 is an oil based temporary coating that provides extreme corrosion protection in aggressive environments. It has been used around the world and, because of its dual lubricity/protection, is often sprayed onto moving parts (CorShield® VpCI®-369) for preservation in offshore layups. Historically, it has rarely, if ever, been used for dip tank applications because of its high viscosity that typically makes it too thick for dip tanks. However, the positive recent experience of the service parts manufacturer who diluted it down to a custom viscosity opens new possibilities for other manufacturers who may want to apply a wet film corrosion inhibitor by dip.

Adapting VpCI®-369 to Dip Tanks

In order to make VpCI®-369 viable for dip tank application, the client worked closely with Cortec® to create a custom dilution that would leave behind the desired 4 mils (100 µm) of protective film after dipping and draining. The client also subjected the product to salt spray and humidity testing to ensure that it passed company specs. The customized version of VpCI®-369 ultimately met full approval on their specification for long-term (up to five years) indoor protection of service parts and has been in use for approximately one year. It is used to dip cylinder sleeves that will be installed directly into equipment engines (no removal required in this case) once the service part is needed.

If you have had positive experiences using this popular wet film rust preventative in the past and would like to adapt it for dip tank use, contact Cortec® for guidance through the process:

Keywords: VpCI-369, corrosion inhibitors, rust preventative for dip tanks, Cortec, offshore layup, preservation of service parts, dip tank application, temporary coating, corrosion protection, long-term preservation

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CASE HISTORY SPOTLIGHT: Case History #769: Stopping Underbody Rust on Collector’s Car

In 2008, the owner of a 1947 Chrysler Windsor decided to passivate the rusty front underbody and interior floor of his collector’s car. He chose to try Cortec® Coatings based on a good experience working with Cortec® products in the Cortec® sample department.

He started his winter restoration by scraping all the grease and grime off the front wheel drums, shock absorbers, and undercarriage. He applied just enough CorrVerter® Rust Converter Primer to stop the rust and followed this with a topcoat of VpCI®-386 Black when the CorrVerter® cured. He used the same two coatings on the rusty floor inside the car.

The owner was impressed with the coatings, especially since he did not have to worry about using flammable products or enduring unpleasant fumes while working in his garage with the heater on and the door closed. When doing brake work almost 14 years later, he was impressed to find that these areas were still clean, solid, and rust-free, with no “rust creep” coming out of the nuts and bolts.

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Keywords: collector car restoration, underbody rust, Chrysler Windsor rust, Cortec Coatings, Cortec samples, stopping underbody rust, Chrysler Windsor restoration, CorrVerter, rust converter, rust primer

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CASE HISTORY SPOTLIGHT: Case History #616: Coating Refrigerator Coils

A refrigerator coil manufacturer was unsatisfied with the solvent-based paint they were using to coat the coils. Workers disliked the strong solvent smell and associated health hazards. Long-term corrosion protection was also deficient. By switching to water based VpCI®-386 in their dip tank, the manufacturer was able to reduce VOCs while improving corrosion performance and the worker environment.

Read the full case history here.

Keywords: solvent based paint alternative, switching to water based paint, coating refrigerator coils, case history spotlight, Cortec, VpCI-386, reduce VOCs, corrosion performance, worker health hazards

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NEWS ALERT: New Demo Video from Cortec®! How to Check Coating Cure

Have you ever been applying a coating out in the field and wanted to know if enough time had passed to apply the topcoat? Our newest demo video shows how to do a quick solvent rub test to make sure your coating has cured.

In this short video, Cortec® Technical Services Manager Rick Shannon explains how to do a solvent rub test and then demonstrates the technique on a panel coated with VpCI®-395 Water-Based Epoxy Primer. Wearing gloves, he rubs a towel dipped in solvent (MEK) back and forth across the panel 25 times to see if any of the coating will come off or fade. Rick finishes the solvent rub with no damage to the coating, confirming that it has fully cured and is ready to be top-coated with another Cortec® Coating.

Making sure a coating has fully cured before applying the second coat on top is critical to good adhesion and the success of the entire coatings system. Without good adhesion, the coating will chip or peel off more easily, exposing the metal to corrosive elements that could damage the surface and cause coating failure altogether, negating corrosion protection. When time is limited and cold weather or other situations make it unclear how long you should wait before recoating, a solvent rub is a quick and easy way to check coating cure. Watch this demo to be prepared next time you need to do an impromptu MEK solvent rub test out in the field:

Keywords: coating failure, Cortec demo video, how to check coating cure, coating adhesion, good adhesion, how long should you wait before recoating, Cortec, Cortec Coatings, MEK solvent rub test, corrosion protection

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PRESS RELEASE: Achieving Superior Corrosion Protection with Water-Based Coatings for OEMs

EcoShield® VpCI®-386

OEMs (original equipment manufacturers) have more than just paint color to consider when choosing a coating for metal parts. In many cases, corrosion protection is also needed to compensate for harsh shipping, storage, or operating conditions components will encounter after coming off the assembly line. Cortec’s EcoShield® 386 series gives manufacturers the opportunity to meet these rust preventative needs while achieving a pleasing appearance with water-based coatings at low DFT (dry film thickness).

EcoShield® for Mass Produced Parts

EcoShield® VpCI®-386 is a fast-drying water-based acrylic one coat system that can be applied DTM (direct to metal) for protection in harsh applications. Excellent UV resistance allows it to be used outdoors in direct sunlight. EcoShield® VpCI®-386 is a great option for dipping thousands of parts for greater efficiency and less paint waste. It can be used to coat

  • Semi-truck wheel rims
  • Coil stock
  • Metal tracks for heavy equipment
  • Refrigerator coils
  • And much more!

EcoShield® VpCI®-386 can be applied as a thin (1.5-3.0 mils [37.5-75 µm] DFT recommended), barely noticeable clear coat or tinted to match a particular brand or equipment color. In either case, corrosion protection with EcoShield® VpCI®-386 adds a professional, finished appearance to the components.

EcoShield® for Force-Dry Applications

EcoShield® 386 FD is a newer version that is a great option for manufacturers working with fast-paced assembly lines where there is not much time for the coating to dry before parts are jumbled together. EcoShield® 386 FD dries quickly in a force-dry environment to reduce sticking of painted parts. With VOCs of only 0.04 lbs/gal (5 g/L), EcoShield® 386 FD qualifies as a zero VOC coating in the US. It was originally designed for a tube steel manufacturer who applied the coating to hundreds, if not thousands, of pipes at 1.0-1.2 mils (25-30 µm) DFT using a Nordson coater box. The manufacturer ended up being able to reduce the overall amount of coating required while still achieving the desired level of protection on the coated OD (outer diameter) during a year of outdoor storage near the Gulf of Mexico.

EcoShield® for High Temps and Surface Slip

Yet another member of the EcoShield® family is EcoShield® VpCI®-386 HT Slip Coating. This anticorrosion coating was designed to offer high heat resistance up to 500 °F (260 °C) or more depending on color choice. It is thixotropic and resists sagging and running. Another special feature of EcoShield® VpCI®-386 HT Slip Coating is that it improves surface slip, which can be particularly helpful when coating the inside of pipes or electrical conduits where wires will be threaded through. EcoShield® VpCI®-386 HT Slip Coating is available in clear, black, or aluminum and is a great option for keeping pipe or electrical conduit internals (ID) corrosion-free in extended storage outdoors.

Whether your coating application falls under general manufacturing conditions or requires special force-dry, high temp, or improved slip qualities, Cortec’s EcoShield® series is a great place to find outstanding corrosion protection in the form of user-friendly water-based coatings with good aesthetics. Contact Cortec® today to learn more:

Keywords: corrosion protection, water-based coatings, coatings for OEMs, slip coating, high temp coating, coat pipes, rust preventative, Cortec, EcoShield 386, anticorrosion coating

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NEWS ALERT: New Cortec® Demo Video: How to Test Coating Adhesion!

We are pleased to release a new demo video on how to test coating adhesion! This test can be very important for coating applicators who want to make sure their first coat of paint has cured enough to apply the second coat-or for applicators who simply want to paint over an old coating. Good coating adhesion is critical to the success of an anticorrosion coating system because if the coating does not stick to the surface, protection is lost. If adhesion is good, the coating can do its job!

Now, painters can watch our new demo video to see how Technical Services Manager, Rick Shannon, tests coating adhesion according to ASTM D3359 on a panel coated with one of Cortec’s Micro-Corrosion Inhibiting Coatings™. Using a special tool from his adhesion test kit, he makes perpendicular cuts to get 100 tiny squares on the surface of a coating. After brushing off the residue, he uses a piece of masking tape to see how many squares of paint he can pull off. Based on this, he calculates the percentage of failure and the level of adhesion.

At the end of the video, Rick explains how to do the same basic test in the field without special equipment. The only tools needed are a utility knife and masking tape. Rick demonstrates how to make 11 cuts in each direction (to get 100 squares), brush off the paint residue, and see how many squares of paint can be pulled off with the masking tape.

Rick often recommends testing coating adhesion to customers. Now, instead of having to get the directions over the phone or via email, customers can watch this short demo video to see how it is done! Watch now:

Keywords: Cortec demo, how to test coating adhesion, adhesion test kit, Cortec Technical Services, anticorrosion coating, micro-corrosion inhibiting coating, demo video, adhesion test demo video, good coating adhesion, testing coating adhesion

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