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OSI HM270 Construction Silicone Sealant (Carton of 12)

- Available in 2 Options. Pricing may vary.

PLEASE NOTE: Once ordered this product immediately goes into processing and cannot be cancelled prior to shipment.

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Product Information


The OSI HM270 Construction Silicone Sealant is a one-part RTV sealant designed for sealing and glazing. It cures at room temperature upon exposure to moisture in the air providing good tensile strength and excellent adhesion, usually without the use of a primer, to most nonporous building materials. OSI HM270 easily withstands temperature extremes from -60°F to 400°F without adverse effects. This sealant from OSI will work with sealing skylights, solar panels, ventilators, aluminum siding and windows, heating/air conditioning units, duct work, recreational vehicles, and other glass, plastic or metal assemblies.


  • Designed for glass, metal, and plastic
  • Water resistant
  • Skins in less than 10 minutes, and is tack free in 25 minutes
  • Very flexible with up to 25% joint movement
  • Extrudes in any weather condition, making it a great year round caulk


Specifications Chart
Make OSI
Model HM270
IDH Number
  • 1493960 - White
  • 1494045 - Clear
Quantity 12
Capacity 10 fluid ounces
Base One-part, acetoxy, moisture-curing silicone rubber
Skinning Time 5 - 10 Minutes
Tack Free Time 25 Mintues
Cure Time 24 Hours
Temperature Range -10° to 250° F
Water Resistant? Yes
Paintable? No
VOC Content % 3%

Helpful Documents

WARNING: California's Proposition 65
Proposition 65 Warning for California Consumers

Prop 65 Warning WARNING: Cancer and Reproductive Harm