J-B Weld White Sealant and Adhesive is a general purpose Sealant Adhesive RTV (Room Temperature Vulcanized) Silicone designed for use in household or mechanical assembly applications. Upon curing, which occurs when the product is exposed to the moisture in air, the silicone forms a tough, waterproof, mildew and mold resistant seal on most surfaces. It will not shrink or crack, resists weathering, is sensor safe and is great for many household and automotive applications.