Epoxy sealants are protective coatings applied to the surface of concrete, masonry and other materials. They differ from other types of sealants in that they consist of two separate components, which undergo a permanent chemical reaction when mixed together. Most epoxy sealants consist of a resinous material and a hardening agent which are suspended in either water or solvents based on the intended application. Different types of epoxy sealants can be distinguished based on whether they are solvent based, water based, or made from 100 percent solids with no water or solvents. Marine or gel sealants represent a fourth type of epoxy sealant, and are designed for high performance applications.
Water-based epoxy sealant serves as the most common type of sealer for light-traffic applications. For example, they may be used to seal a residential driveway or countertop. Water-based epoxy sealant features little odor and is considered less toxic than other versions of this product. While it costs less than oil- or solvent-based sealants, it also tends to be less durable, and may develop stains or discoloration over time.
Solvent-based epoxy sealant products are a mid-range option for moderate traffic applications. For example, this product could be used to seal a floor or parking lot in a small retail store. These sealants consist of a hardening agent which has been suspended in a solution of water and chemical solvents. They cost more than water-based products, but also tend to perform better. Solvent-based epoxy sealants produce fewer harmful fumes than those made from 100 percent solids, but more than water-based sealants.
For heavy-duty industrial applications, an epoxy sealant made from 100 percent solids often provides the most durable and longest lasting solution. Rather than suspending a solid in water or solvents, 100 percent of the solids are transformed into a sealant when mixed with the resin. There is no dilution, which means that the final sealant won't shrink or crack. This results in the most effective coverage, but also comes at the highest cost.
For extremely harsh conditions, a marine or gel sealant may be required. These 100-percent-solid epoxy sealants incorporate the most advanced hardeners and resins on the market, which allows them to withstand exposure to chemicals or saltwater. These sealants are tend to be the most expensive of all epoxy sealers, and often produce harmful fumes. They must be protected from ultraviolet rays and frequent sun exposure to maximize their effectiveness.