05.22.2025

Heat-Resistant DOWSIL™ Sealants: Made to Perform Under Extreme Temperatures

Heat-Resistant DOWSIL™ Sealants: Made to Perform Under Extreme Temperatures

In high-temperature environments, standard sealants can’t always hold up. That’s where DOWSIL™ heat-resistant sealants come in. Engineered by Dow, these advanced silicone formulations are trusted in demanding industries for their durability, flexibility, and long-lasting performance under extreme heat. 

Here’s a breakdown of three standout products in the DOWSIL™ high-temp line and what makes them essential for industrial and commercial use: 

DOWSIL™ Hi-Temp Sealant Red 

This one-part silicone sealant is formulated with iron oxide to endure intense heat exposure. It is ideal for situations where components must withstand continuous high temperatures without compromising the seal. 

APPLICATIONS

  • Fired heaters 
  • Access doors and flanged pipe joints 
  • Flues on gas appliances 
  • Appliance heating elements 

FEATURES

  • Withstands continuous temperatures up to 500°F (260°C), and intermittent peaks up to 550°F (288°C) 
  • Remains flexible and resists cracking, shrinking, and chalking 
  • Strong adhesion and weather resistance 
  • Fast curing with high-strength 

DOWSIL™ 736 Heat Resistant Sealant 

DOWSIL™ 736 is a non-slumping silicone sealant designed for bonding and sealing surfaces exposed to temperatures as high as 600°F (316°C). It’s especially suited for vertical or overhead applications for sag resistance. 

APPLICATIONS

  • Electrical enclosures and connections 
  • Sealing and insulating heating elements 
  • Aerospace gasket 
  • Moving oven belts 
  • Bag filters on smokestacks 

FEATURES

  • Resists sag and run 
  • One-component silicone 
  • MIL-A-46106B and FDA/NSF compliance 
  • Excellent high-temp durability and electrical insulation 

DOWSIL™ Q3-1566 Heat Resistant Adhesive / Sealant 

Formulated for high-temp resistance and superior adhesion, DOWSIL™ Q3-1566 cures at room temperature and forms a strong, flexible bond.  

APPLICATIONS

  • Ovens, cookers, and other heating equipment 
  • Automotive and other coolant sealing applications 
  • Electrical and other high-heat sealing scenarios 

FEATURES

  • Can withstand –58°F to 572°F (–50°C to 300°C), with peak tolerances up to 662°F (350°C) 
  • Non-sag, paste consistency 
  • Maintains flexibility across wide temperature ranges 
  • Unprimed adhesion on glass, metals, and most common plastics 

Each DOWSIL™ sealant is designed to perform in specific high-temperature scenarios. Whether you need a general-purpose sealant for heating appliances or an advanced formula, DOWSIL™ has a solution. 

To order any of these DOWSIL™ products or to find the right sealant for your application, email Orders@LentusLLC.com or call 270-765-2212.  

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