What is Waterproof Silicone?

Waterproof silicone is a silicon-based, synthetic material used as a waterproof sealant for weatherproofing, thermal insulation, and moisture-resistant enclosures. The compound is generally rubbery, strong, and non-absorbent. Silicone sealants are often used to caulk airtight joint seals when constructing watertight objects; used as a water-resistant coating to protect building materials or outdoor machinery frequently exposed to moisture; or even applied to clothing to create waterproof materials. The most common forms of waterproof silicone include silicone film, silicone spray, and silicone gel.

As a waterproof sealant, silicone can also act as a glue to join parts of a structure, such as the individual panes of glass in aquarium walls. The silicone joins the glass panes at the corners and fills in the microscopic porous spaces between the glass fibers, preventing water from passing. This sort of waterproofing technique has also been used on boats and submarines — not just on windows, but on the joints of interconnected parts that are often partially or entirely submerged in water.

Industrial uses commonly include sealing liquid vats or transport containers to prevent leakage, to keep fluids in rather than out. In construction, silicone sealants are frequently used as coatings for building materials. They are also utilized to close gaps in plumbing and fixtures, and to create watertight masonry structures.

More common uses can range from technology to personal devices. Waterproof silicone has been used to manufacture multiple-shaped devices, particularly those with sensitive electronic components that require a flexible, molded waterproof casing. These devices range from waterproof computer keyboards to protective cases for personal electronics, battery-operated personal massagers, and insulating cases for liquid containers. The malleable nature of silicone enables it to be shaped to precise purposes, while retaining a flexibility that allows for easy fitting over various devices. The water-resistant nature of the substance prevents moisture from disrupting the functionality of electronic circuits and other conductive components.

Although almost all are referred to as waterproof silicone, silicone sealants can be formed from any number of silicon compounds, including siloxane, silane, and silicone rubber. Each has a different chemical formula, resulting in different properties, depending on their use. Silane is typically applied to a porous surface and reacts with it, to form a waterproof resin coating that penetrates and fills any areas that might allow liquid in. Siloxane performs a similar function, but does not penetrate as deeply. Waterproof silicone rubber provides a thicker coating, with more elasticity and durability than either silane or siloxane.