My boats a 17 ft. aluminum. Noticed that on the inside of the transom on both sides next to where the motor mounts, there is some seperation. This is about a foot long & the caulking is split & the aluminum has a gap about 3/8 of an inch. If I push on the back of the transom the gap will close halfway but not completely. What would you guys recommend to fill this up rather than a caulk ? I would like to use something that would bond & strenghthen this. The rest of the transom looks fine & I use a transom saver. I would like to avoid any problems down the road with this. Thanks for any replies.