ive seen that gorlilla glue once or twice. one of the guys we contract for suggested we use it once, but we never do. just set in our ways i guess
i do interior trim for a living, so i work with MDF every day, and when i build my box im going to use subfloor adhesive and 2 inch trim nails for the whole box. it doesnt dry as fast, but it seals very well. on the inside, my friend is going to fiberglass the whole thing. not sure why but im guessing it will seal everthing and make it a perfect solid sealed structure.