Difference between epoxy and polyaspartic coating
Polyaspartic Floor Coatings Polyaspartic coatings have been around for decades and found their first uses in corrosion control applications on metal and concrete parts of bridge structures. Around 2005, Slide-Lok Garage Interiors, was one of the very first players in the garage makeover and garage improvement market to use Polyaspartic resin technology for garage floor coatings. In those days, nearly everyone on the market resisted the technology and tried to push epoxy, thinking polyaspartic would not hang around and would not hold up. Well, it did hang around and for many, many years. It has proven to hold up very well in a wide variety of conditions and Slide-Lok was one of the very first to use polyaspartics in the garage concrete flooring market. In the last few years, the advantages and long term reliability of polyaspartic has become so widely known and apparent that today, many contractors offer polyaspartic resins in addition to epoxy.
Polyaspartic coatings are a great option for many reasons. For one, it is very easy to apply and can typically be done in only one day; minimizing installation trips, cost, and inconvenience to home owners. This coating is also easy to apply in extreme temperatures from hot to cold, which can allow you flexibility in deciding when you would like to have your project done. Unless working with a very exotic epoxy formulation, as a rule of thumb, epoxies should not be used when temperatures are below 55 degrees F and for those contractors that use only epoxy, their installs come to a halt when fall temperatures start dropping. Polyaspartics can be used in temperatures well below zero.
One of the early advantages of polyaspartic coatings is that they are UV stable which makes for a great top coat, meaning that it will not discolor or yellow from the sun. This yellowing or ambering is perhaps one of the famous shortcomings of most epoxy formulations. Polyaspartics also feature excellent scratch resistance, making them extremely durable and useful for areas of high traffic. As well, they are much, much more elastic than epoxies, meaning that when your concrete expands and contracts with changes in temperatures, the polyaspartic floor coating will “move” with the concrete much better and as a result, adhesion to the concrete is highly improved. Polyaspartic floor coatings are however a more expensive option than epoxy.
Epoxy Floor Coatings Epoxies have been around for many, many decades and their main advantage is their low cost. When it comes to flooring, epoxies tend to be less elastic and in environments where the substrate, concrete, is exposed to wide temperature variations over the course of the year, they can “pop” off the floor. Below 55 degrees Fahrenheit, epoxies are a ‘no go’ for installation as curing can be extremely slow and/or result in partially cured flooring systems. Even when you’re within the right application temperature, epoxy takes longer to cure than Polyaspartic, usually taking five to seven days before you can use the floor compared to 24 hours with polyaspartic floor coatings. And of course, mostly all epoxy floor coatings use a similar resin technology based on DGEBA (bisphenol-A and epichlorohydrin) which features an aromatic ring, making it inherently flawed to yellowing and ambering when exposed to the sun (radiation). If the floor will be exposed to UV light from the sun, over time, epoxies will yellow and should not be recommended for outdoor or sunlight exposed floors.
Be wary of newer companies touting “100% UV Resistant Epoxies” or derivatives thereof. Many of these companies are using the same commercially available epoxy resins (DGEBA) as the lower cost epoxies and pairing it with a higher cost cycloaliphatic amine (hardener). While this system has enhanced UV resistance to yellowing/ambering, it is only temporary. The system may last 6 months longer than a floor without a cycloaliphatic hardener, but it will yellow just the same in time. It wouldn’t be honest to say that technically a 100% UV resistant epoxy could not exist, it could, but at this moment in time it would make absolutely zero sense from a financial and a technical standpoint. There are a few saturated cycloaliphatic epoxy resins that exist in the marketplace that could be paired with a cycloaliphatic hardener, but these are so inherently expensive to manufacture and are not widely used simply because they are not being manufactured. The largest epoxy manufacturers in the world do not even make these types of resins for flooring because of drawbacks such as increased cost, poor cure rate, unsuitable film formation, etc… They are so cost prohibitive to introduce for the increase in UV protection that the recommendation is simply to use a polyurethane / polyaspartic flooring system which also comes with other improved technical performance aspects such as increased cure, hardness, elasticity, etc…