Make sure you get the bottom sealed extra good under the lip where the Plywood is joined ... I had those Little tiny Black Ants my Grandmother Called Sugar Ants make their home in the Side Boards on my Boat trailer --- until it was eaten up --- the only way I know would be to stand the Boat up till the Transom was flat to allow Everything to cure and not run out from between the Plywood... My Grandpaws barn is over 120 years old could hoist it rite up and let you work in the shade