Frequently Asked Questions – General

What is Polyurea?

Polyurea is an organic polymer that is the reaction of isocyanate with an amine terminated polyether resin, forming a plastic-like or rubber-like compound that may be used in many of the same ways as older technologies – polyurethane, epoxy, vinyl ester, neoprene; to name a few.

Can anyone apply Polyurea?

Polyurea requires special training and equipment for field application, whether used as joint filler or as a field applied coating. VersaFlex has an ongoing program of contractor trainingin place. There are qualified applicators in all regions of the U.S. and an expanding network of qualified applicators throughout the world.

Where can polyurea be used?

As a general rule, VersaFlex polyurea can be employed to contain any substance that may be directly discharged into normal sanitary sewer systems. It may be easier to give examples of environments where polyurea should not be used.  As a general recommendation for constant exposure to direct chemical attack VersaFlex polyurea products may not be installed for attack by:

  • Halogenated Solvents
    • Carbon tetrachloride
    • Chloroform
    • Methylene chloride
    • Tetrachloroethane
    • Trichlorethene
    • Trichloroethane
  • Non-Halogenated Solvents and Ketones
    • Acetone
    • Acetonitrile
    • Acetophenone
    • Benzene
    • Butanol
    • Camphor oil
    • Cyclohexanone
    • Diethyl ether
    • Diisobutyl ketone
    • Ethyl acetate
    • Hexane
    • Methyl ethyl ketone
    • Methyl isobutyl ketone
    • Pentane
    • Phenol
    • Toluene
    • Xylene
  • Acidic compounds with a total composite pH range equal to or below 4
  • Basic compounds with a total composite pH range equal to or above 11 Note: Non-aqueous (anhydrous and anhydride compounds in granular, crystalline, or powder form) protected by an air drying system may be contained by polyurea. Consult VersaFlex.
  • Amine Attacking And Amine Containing Compounds Strong, inorganic acids, organic acid halides, aldehydes, isocyanates, organic anhydrides
    • Aminoethylethanolamine
    • Aniline
    • Ethylamine
    • Methylamine
    • Pyridine
    • Toluenediamine

What kind of temperatures will polyurea withstand (and will it burn)?

VersaFlex polyureas begin to develop their physical properties within minutes of application.  Among several very desirable properties are their quick gel time and their glass transition temperatures that average -40° F and +480° F.   Heat of deflection under no load is +250°F, depending on system. Safe upper limit of working temperature is +350°F, under no load; again, dependent of system.  Polyurea will exhibit thermal shock debonding when subject to repeated periodic blasts of live steam.  While polyurea has high glass transition and heat of deflection temperatures, it will burn when exposed to direct flame. It will self extinguish when flame is removed.

Is polyurea hard or soft?

Polyurea may be either hard or soft depending on the particular formulation and the intended use. Durometer ratings may range from Shore A 30 (very soft) to Shore D 80 (very hard).

What’s the difference between Aliphatic and Aromatic polyurea systems?

Actually there are two different types of aliphatic polyurea systems currently on the market.  One is the typical high pressure/temperature sprayed systems and the other is what is known as a “polyaspartic polyurea” type system.  This polyaspartic system is different in that it uses an ester based resin component and has a longer pot life.  It can be hand applied using close nap rollers; brushes; rakes or even airless sprayers.  The aspartic systems are not the high build coating typical of the “hot spray” polyurea systems.   The typical aromatic polyurea systems must be processed through high pressure, heated plural component pumps and sprayed through an impingement type spray-gun.  This is true also for the aliphatic version of this type of system, the primary difference being the color stability of the aliphatic systems.

Application Specific Questions

Can you give an overview of the chemical resistance of polyurea to solvents, acids, treated water, etc?

Each product on our website has Chemical Resistance charts under the Documents tab. Example link: Chemical Resistance – Aromatics.

One of our workhorses when it comes to very harsh chemical exposure is VT-40™.

Furthermore, if you have a specific chemical you’re dealing with (or a specific application), feel free to contact us so we can help you determine the best system for your needs.

Besides shrinkage during cure or cooling of standard aromatic polyurea liners, is there a specific shrinkage or creep we need to take into account for long-term liner systems?

It does depend on the formulation, although in VersaFlex’s particular formulations, the polyurea will not shrink after it has cured.

However, this is a good question to ask of anyone you choose to buy material from – does your material shrink or not?

On FSS45DC or FSS50DM applications with a below grade waterproofing application, would we have any issues with two separate areas, sprayed at two different times, adhering to one another at the overlapping joints?

With good surface preparation, no, you would not have issues. You would typically prep the overlap of the old polyurea (very light grind/sand and then wipe down with a little solvent to wake the polyurea back up). We recommend using Dzolv or VF Tackcoat for this step in the process, and then continuing with proper surface prep and cleaning everywhere else.

What is the shrinkage for FSS 45DC™ compared with VF 380™? Can they be applied over high density polystyrene foam?

FSS 45DC™  is about 1.5% shrinkage and VF 380™ is < 1.0% shrinkage. Either can be applied over high density EPS.

Do you have some kind of polyurea with anti-abrasive and anti-adherent characteristics for mining trucks?

We have the perfect product for this type of application, our VF 330™. This product has been tested extensively in the mining industry, and has consistently performed above expectations.

How much is polyurea being used for floor coatings? Or is this new to the floor coating industries (industrial)?

Both our industrial and decorative flooring systems have been in use for years; this is not something new to the flooring industry. Unfortunately we do not have estimates on overall usage, but again, this is definitely not something new.

We also have an anti-microbial additive, CrobeFlex®, that is being used in hospitals, clean rooms, food storage, and veterinary clinics.

When used as a RV roofing material, what are suitable substrates?

There are a lot of variables here, but since most RV roofs are made of either aluminum/painted aluminum or a painted composite, these would be suitable substrates for our coating systems.

Prep would depend on: a) what the actual substrate is, b) is it new or old, c) is paint still present, etc.

We have several products that would be suitable for this type of project.

What about stainless steel? Which would be the best product and what would be the surface preparation?

Our first question would be, “Why do you want to coat stainless steel?” First you’d want to identify the purpose for coating stainless steel, as this substrate has superior corrosion resistance on its own. But if it is to be coated, then please follow SSPC-SP 16 – “Brush-off Blast Cleaning of Coated and Uncoated Galvanized Steel, Stainless Steel, and Non-Ferrous Metals” for proper surface preparation techniques.

In many cases, a vinyl wash primer is then used, applied very thin via spray application. The “best” polyurea product to then use as a coating will depend on why the stainless steel is being coating (purpose / function). If you can provide additional information on this use (contact us), then the appropriate system can be suggested.

I hear some companies saying polyurea is not as good as epoxies when it comes to corrosion protection. Can you point out how polyurea is better than epoxy on metal? Also, do you have any good 10-year case studies on immersion / metal projects?

For immersion / steel applications, keep in mind that PUA (polyureas) and epoxy are not the same. They are both descriptions of technologies / a product type. PUA systems do work well for immersion, but they must be properly formulated for that application.

While epoxy systems are significantly more rigid, PUA systems have superior flexibility and low permeation rates for properly formulated systems. PUA is also a much quicker return-to-service material in general — polyurea cures within hours compared to days (or sometimes weeks) for epoxies. However, the big issue with this type of work and steel substrates is that surface preparation is critical. This MUST be done properly / completely. This is where most have had issues when attempting these type projects.

Check out our Projects page for profiles on this and many other types of applications.

Is it proper to use a 600% elongation polyurea system for a roof waterproofing over concrete?

For concrete roofing, some of the system characteristics will depend on the type and condition of the concrete roof. However, we suggest being very careful with this terminology / characteristic of “600% elongation”. There are many successful concrete roof deck applications that use PUA systems with 200-400% elongation.

The term “% Elongation” reported on a data sheet is derived from ASTM testing. Basically, this is the percentage of stretch to failure from a starting point. If the starting distance is “0” then 600% of “0” is still pretty close to zero.

You must take care of your surface preparation and treatment of penetrations and cracks in the roof deck. If there is considerable movement in the roof deck, you must have a good balance between elongation and material tensile strength.

This is covered in our Applicator Schools at Polyurea University.

What is the proper weight per m2 of geotextile fabric?

For geotextile fabric, the common weight used is 4oz to 8oz, but depending upon the type of work, substrate, and traffic, some will use 10-12oz. And that is oz/sq yard.

So, for the 4-8oz/sq yard = 0.53kg to 1.05kg / m2.

For the 10-12oz/sq yard = 1.3 to 1.6kg / m2.

What primer would be best on sprayed polyurethane if the foam needs to be cut back and the cell structure opened up?

Our VF 20™ would work for this type of application.

What is the best flooring solution/system with anti slip properties for an industrial environment with a lot of oil / grease spillages and forklifts etc, and with easy to clean/maintenance properties? Any oil tolerant primers to go with it as the substrate/screed is also contaminated in certain areas?

What you are really looking for, and the proper term, is a “slip-resistant” system. For us here in the US / North America, we go by OSHA safety guidelines, and that value is 0.50. For ADA (Americans with Disabilities Act), that value is 0.60. For ramp / inclined areas, the value is 0.80. One way to measure in the field is by use of ASTM F 609, Standard Test Method for Using a Horizontal Pull Slipmeter (HPS).

For applied liquid coating systems, such as polyurea systems, aggregate is usually added to improve that perceived “slip resistance”, and does work quite well. However, once the aggregate is included, the coated floor area may in fact be more difficult to clean, especially with conventional wet mopping or brooming. For this, a power wash / scrubber system would then be used.

Or, for a kitchen floor application where water, food stuff, or grease may spill, they may use a slight texture so as to be easier to clean. But then they also require employees to wear specific shoes with soft soles, not leather soles.

You could also use a softer PUA coating system that would work fine for foot traffic, and would be easier to clean, but would not hold up well to forklift / heavy vehicle traffic.

The best flooring system for the specific application you have described may in fact be one of the urethane – concrete systems. These are popular and do perform well, and can be cleaned. However, if oil / grease is spilled and not cleaned up properly, they can become quite slippery.

So the question you have to ask: Do you want the flooring system to be highly slip resistant, or do you want the floor to be easily cleaned? These are often somewhat exclusive.

As far as ‘oil tolerant’ primers, we do have both our VF 20™ (urethane based) and VF 30™ (epoxy based) products that would work. Note: Use of these products does not mean NO SURFACE preparation required — you still must perform proper surface preparation and remove heavy oil / grease from the surface before use of either of these primers.

How can we avoid bubbling on polyurea film? To clarify: after spraying polyurea and letting it dry for between 1 – 7+ days, the polyurea becomes like a balloon in some areas exposed to direct sun light. Heat here in Saudi Arabia reaches 48°C [118.4°F], so how can we avoid this and how to repair professionally?

Things to check: Are these blisters / balloons between layers / within the polyurea, or between the applied polyurea and the substrate? There are various answers depending upon the situation.

It could be that this is not a true polyurea, but rather a cheap hybrid passed off as a polyurea, and it simply does not have the thermal stability given the heat exposure.

It could be that this is a polyurea, but that the substrate / priming was not performed properly.

Or it could be that the mix was off-ratio / off-mix due to incorrect equipment set-up and use.

To repair, you must cut that blister out, abrade the surface, and possibly prime depending upon whose polyurea (or hybrid) is being used and their recommendation. The re-spray into that prepared area.

What product would you recommend for coating EPS, with the hardest rating?

You can coat EPS with any of the following products:

VF 380™, hardness about 35 shore D.
FSS 45DC™ / VF 350™, hardness about 45 Shore D.
FSS 50DM™ / VF 320™, hardness about 50 Shore D.
FSS 42D™ (aliphatic), hardness about 42 – 45 Shore D.
AroStruct®, hardness about 65 Shore D.
LS / 75™, hardness about 75 – 80 Shore A.

If you can let us know what you are using the EPS for, we can better direct you to the appropriate system / product.

Can VF 330™ be applied in relatively thin coatings (15-25 mil)?

Yes, the VF 330™ can be applied at 15 – 25 mil thickness with the proper equipment setup and spray gun for the small parts.  You would have to use either the GUSMER / GRACO GX-8 or the Pentech MG spray gun.

Would you need to prime a capsheet flat roof?

In this type application, it is best to spray foam (3 pcf) and then coat the foam with VF 380™.

Will a Graco H-40 spray polyurea? Graco E-30?

Both the H-40 (~45 lbs/min) and the E-30 (~30 lbs/min) could be used for PUA. They both have max pressure of about 2000 psi, but high output, flow rate.

The main issues will be what size heaters are present, and if they can keep up, and the hose length.

The H-40 would be “better” or more consistent. Also, you must have the right chamber in the spray gun. If it’s an air purge, an AW 3737 would work. This would be like the GUSMER H-2000 we used years ago.

What polyurea would you recommend for repairing cracks on the deck of a 50-year-old city swimming pool? The cracks are not in the pool, they are outside on the walking area.

For pool deck repairs, you could use FX Mender™ after the cracks have been prepped with either a thin flat concrete blade (not a “V” blade), or a wire wheel on an angle grinder and vacuumed. Use a good high output heat gun or propane torch to remove moisture in the cracks to be repaired. Install FX Mender™ slightly lower than the crack and top with dry quartz sand the same color as the concrete deck. Press sand into the FX Mender™.

SL/60™ material could also be used with the same method as above, pressing sand into the material. If using SL/60™, you would need to be a little quicker getting the sand on top, as it has a shorter window of workability.

Can SacriShield™ be used over painted / powder coated parts to protect the finish? How easily can it be removed?

SacriShield™ will not stick / bond to the powder coating. However, if it is a small or complex part, then there will be overlap and possible interaction with the detail of the part, but not from adhesion to the powder coating. Typically it is not difficult to remove when necessary.

What kind of low pressure spray equipment could be used for coating signs / foam and then coating over with polyurea, and what would be the best system to use?

Any one of the AST pumps listed below would suffice for doing low pressure spray work.

PCH GMP-025
PCH GMP-050
PCH GMP-075

SL/60™ or SL/75™ would be fine. However, it may depend if you’re dealing with vertical applications or not. If so, then there is more technique required, and you may want to consider high pressure spray instead.

What kind of paint to use when going over polyurea?

Generally, a good quality 100% acrylic latex house paint works well over sprayed polyurea. It is usually best to coat over the polyurea (sooner rather than later) within 24 hours of application. This promotes the best adhesion.

I am looking at getting into large lagoon building for animal waste using a polyurea product over geotextile. How many square feet per can be applied per hour?  Approximately what would it cost the consumer per square foot?

The product you would want to use is our VF 380™.

The amount (or square footage) one can apply in an hour will depend on numerous factors. These depend upon the output capability of the spray equipment (typically either 1 or 2 gallons per minute), how thick the VF 380™ is being applied to the geotextile fabric, and if pre-sprayed panels are used and then joined in the field.

The typical thickness of application will be 60 to 80 mils (1.5 – 2 mm) of the VF 380™.  Most applicators are using an equipment setup of 1 gallon per minute, while some have 2 gallons/minute.  So given that, the following theoretical coverage rate is noted:

60 – 80 mils:                    1 gallon/minute output                       1200 – 1600 square feet/hour

60 – 80 mils:                    2 gallon/minute output                       2400 – 3200 square feet/hour

The above is theoretical, and notes continuous spraying for 1 hour.  Actual output will depend on experience level of the applicator, the complexity of the area, as well as environmental factors (wind for example), just to name a few of the factors to consider.

It is very hard to answer exactly how much it would cost per sq. ft. because of the lack of information per each job; applicator experience, equipment, travel requirements, size of job, profit margins required by the applicator, etc. However, given the standard list price of VF 380™, the average cost per square foot of VF 380™ will typically be about $1.50 to $2.00/square foot at the thickness range noted above. The geotextile fabric can range from about $0.05 to $0.20/square foot depending upon the type and weight used, as well as volume purchased.

What does VersaFlex offer as a crack filler for polished concrete?

We have a few products that are used for crack fill work in polished concrete applications. The most common would be our Quick Mender® material. Quick Mender® does contain solvent, and does possess an odor, however, we also have a Quick Mender® L.O. (low odor) version. Both versions are aromatic based technologies.

In some cases, the need for a more color stable system is required, and for this we have our FX Mender™. Being aliphatic based, this product is a premium system with a higher cost, but 100% solids.

We are interested in applying polyurea on flexible polyurethane foam for the development of outdoor furniture. We are in the process of acquiring a E10hp Graco Reactor – what are your thoughts about the suitability of this machine? Our other main questions are: What kind of polyurea is applied to the flexible polyurethane? Will we need primers? What is the color management in the application and durability?

Our suggestions will be based on the information you’ve given here — you’re using flexible foam as a substrate and will need good flexibility – your best bet is our VF 380™ system. No primer would be needed. However, VF 380™ is an aromatic system, and will hold all its properties but the color will fade over time. The darker colors and tan stay true much longer than the light grays, and you always have the option to coat with the VF 380™ material and then top coat with an acrylic latex paint.

The E-10HP is not really suitable for continuous spray work. We know you have probably seen it on numerous YouTube videos, but that machine will not last / keep up with production work if you are going to make a lot of furniture; those videos do not present the complete truth. Additionally, our VF 380™ will not spray well with that setup. That being said, we do not recommend the E-10HP to spray our VF 380™ material.

What product and primer would you recommend for coating a swimming pool with a gel coat?

 

In order to complete a swimming pool project with polyurea successfully, you’ll need to make sure the substrate surface preparation is performed correctly, and that the proper polyurea systems are used.

Aromatic-based system cannot be used alone as the chlorinated water will attack the surface of the coating and lead to failure. A top coating must be used that is resistant to the oxidizing effect of the chlorinated water.

Once you have determined that the concrete substrate is sound, and all repairs are made, the concrete should then be properly primed with our VF 20™ primer, or with our VF 30™ epoxy primer. Then, apply our FSS 45DC™ aromatic-based polyurea at a minimum average of 60-80 mils thickness. Within the 24 hour re-coat window of FSS 45DC, apply our GelFlex® 1115 aliphatic-based polyurea system (minimum average 10-15 mils) to completely cover the FSS 45DC™.

Please note that for swimming pool application work, VersaFlex WILL NOT provide any workmanship or application warranty. That is all up to you, the applicator of the material. We will only warranty the material itself for a period of 1 year as meeting noted physical properties and characteristics, provided the material is processed and applied as to our and industry standards for this type application work.