Optimize Sealant Geometry for Movement

apparently the last reason to use backer on is actually because of kind of the the geometry of the joint you see how this looks kind of like an hourglass right it's kind of thinner in the middle wider on top if this was just a flat bead we wouldn't have that and that hourglass actually gives you a few things so first off you get a lot of surface area for adhesion right so it's going to stick better but if this was this thick the whole way it actually wouldn't move as well right so having it a little thinner in the middle makes it so that it's more relaxed when it needs to move I've always thought they've just