Tested to meet ASTM E595, a standard used by NASA, these compounds produce almost no volatile emissions that could damage sensitive electronics, even in a vacuum. Light passes through them easily, so they’re ideal for protecting solar cells and fiber optics. Made of silicone rubber, these compounds are softer and more flexible than epoxy and urethane compounds. That means they’re better at protecting against shocks and vibration. They also withstand a wider range of temperatures, so you can use them with electronics that heat and cool rapidly. These compounds are excellent electrical insulators, and they’ll shield your components from moisture and dust. However, they don’t hold up well to chemicals or scrapes. They’re also known as RTV (room-temperature vulcanizing).

These compounds are easy to apply in high volumes. Just mix the two parts together and pour them over components inside a container, such as a potting box.