So your are using the 3M 4000 as a "gasket." To do it right, you want to do as described above. Put a bead around hatch opening. Don't leave any gaps. Place the hatch and gently secure it. Try not to squeeze much, if anything, out. That will give you adhesion between the hatch and deck. Let it set up -- read the instructions for cure times. Then, tighten everything down.Well I did something wrong, as water was pouring in quite a bit, can I use too much of the 3M 4000?
As an aside, make sure you sealed the edges of the wood you replaced with resin so it doesn't take up water as the hatch is a potential leak point.