Once you've cut and/or reconnected your strips, you can cover any open components with some high-grade silicon sealant. We use the same type of silicon gel to coat our IP65 LED strip lights, so you know it's good! The seal will be strong and water tight if used properly, and if you're using connectors, feel free to coat the connector in the silicon as well (though this seals it tight, it can make the connector tougher to get to if there are any issues. [links]