Sealant Chemistries
Sealant chemistry can be complex, so working with experts to determine the best option for your application could save you time and money. We can help you choose from a multitude of sealant formulas, which include polymers, silicones, acrylics, and elastomerics.
The application and environment the sealant will be exposed to is very important in determining the best compound to use, so we will thoroughly review your application and its details before offering a suggestion and a sample.
Which Sealant Chemistry is Right For You?
Sealants
Acrylic sealants are best known for their fast cure times and strong adhesion, and they work well on a variety of substrates including wood, drywall, and concrete. They are very cost-effective and widely available, making them a popular choice for many applications. Acrylics can be easily painted over once they have been applied, which is a distinct advantage over silicone sealants, which do not allow paint to stick.
What you gain in convenience and cost with acrylics, you may lose in durability and quality over time. They are not well-suited for high temperature environments, and are not flexible compounds. They also do not stand up to direct exposure to sunlight over time. Because of this, they may crack or shrink, leaving your seal compromised. Acrylics are not moisture-resistant and should not be used as a method to seal out water.
Benefits
Very fast cure times.
Cost-effective and widely available.
Drawbacks
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Not very durable in outdoor conditions.
Cannot be used for water sealing.
Sealants
Perhaps the most well-known sealant chemistry, silicone is a popular choice due to its durability and flexibility. Silicones work well on many substrates including glass, plastic, metal, tile, and more. They can withstand expansion and contraction of the substrate materials due to their flexible characteristics, and they hold up well to harsh conditions such as high temperatures and direct exposure to sunlight. They are also an excellent water sealant and can be used in wet areas. With proper installation, a good silicone sealant can last up to 20 years.
Silicones are more expensive than some other chemistries, but their performance makes up for the difference in price. Other drawbacks include a slower cure time, relatively speaking, and the inability to apply paint over the seal. For that reason, silicones come in many colors to match paint since they must be applied after painting is complete.
Benefits
Very durable and flexible.
Can last up to 20 years.
Drawbacks
More expensive than other chemistries.
Slower cure times than other chemistries.
Sealants
There are a variety of polymer-based sealants, each with unique properties. Polyurethanes are the most widely used among the polymer family. They are UV and water resistant, and they can be painted over. Polyurethanes are also durable and are an excellent choice for bonding joints, as they cure quickly and form a hard seal which makes post-application sanding possible.
The main downside to polyurethanes is that they do not perform well in cold environments. They also require heat to cure. Therefore, application of a polyurethane in cold temperatures may not be possible without additional equipment to provide heat. Once cured, polyurethanes still struggle with cold temperatures, meaning that they may crack and deteriorate over time. Lastly, their shelf life is not long, so they must be used in a reasonable timeframe from the date of manufacture.
Benefits
Excellent for joint sealing.
UV and water resistant.
Drawbacks
Not suited for cold temp conditions.
Relatively short shelf life.
Sealants
The term elastomeric refers to the presence of rubber. Therefore, any of the other sealant chemistries can become elastomeric with the addition of rubber. Elastomeric sealants are very durable, flexible, and can be used in a wide variety of applications and on many different substrates. Because of their flexible nature, these sealants perform very well in applications where joints expand and contract, or where the substrates are exposed to vibration or impact. They are waterproof, durable in outdoor environments, cost-effective, and resistant to chemicals.
Because elastomers are simply sealants with rubber added to the composition, the drawbacks associated with elastomers typically coincide with the drawbacks of their base formulation. For example, an acrylic elastomer will increase the flexibility of the acrylic sealant, but it will still be a less than ideal choice for outdoor applications due to the poor UV resistance of acrylic.
Benefits
Can enhance durability and flexibility of base compound.
Drawbacks
Depends on the base composition.
