Adhesives Magazine

Tips for Selecting a Building Sealant

July 1, 2008


With so many products to choose from, selecting the right building sealant may seem like a daunting task. Selecting the wrong building sealant, or applying the correct sealant in the wrong manner, can have serious consequences. Mike Blaszkowksi, Dow Corning Marketing manager, recommends that you keep the eventual application of your sealant in mind, and also make sure it has the following characteristics.

1. Stability Over a Wide Temperature Range
Once fully cured, high-quality sealants perform across a range of temperatures. The best sealants can withstand temperatures between -85° and 599°F (-65–315°C). Select a sealant that functions reliably at temperatures outside the performance range to accommodate unexpected temperature changes.

2. Weather Resistance and Chemical Stability
UV rays, radiation and weather can cause low-quality sealants to crack, crumble and become brittle, compromising the seal over time. Look for sealants with good resistance to these and other erosive factors. Also, some organic sealants react to atmospheric pollutants or chemicals much like iron reacts with water to produce rust. Use a sealant that does not readily degrade after prolonged contact with common elements and industrial chemicals.

3. Good Bond Strength
Good industrial-assembly sealants provide durable adhesion to a variety of building materials, including glass, ceramics, wood masonry, and many metals and plastics. A variety of factors contribute to the bond strength of individual sealants, including chemical composition, cure type and substrate penetration.

4. Low Flammability
In fire conditions, some sealants are more burn resistant than others. Silicone sealants, in particular, are especially reluctant to burn, and many comply with UL-flammability standards.

Most importantly, be sure to select a sealant that can perform at the highest temperature you require but also offers a secure and flexible hold at lower temperatures.  When in doubt, consult with a qualified expert.

For more information, visit www.dowcorning.com.

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