To make it really easy on yourself get the type that comes in a tube. Squirt it on, smooth it over, job done.

There is a gap between the two panes that acts as a barrier. [6] X Expert Source Kevin TurnerCommercial Handyman Expert Interview. 15 July 2020. It prevents the outside and inside temperatures from affecting each other. [7] X Expert Source Kevin TurnerCommercial Handyman Expert Interview. 15 July 2020.