Once your dry fit is confirmed parallel, and all sides of the mushroom head sit flush on the hulls exterior you will need to do one more round of de-waxing of both hull and backing block.


After that is done you need to wax both the flange (not the backer block) and the thru-hull with copious amounts of mold release wax, butchers wax or even Collinite. The wax should be a paste type carnuba. After you have waxed it cut a scrap board to length and wedge the thru-hull into place. If you are on gravel or dirt lay a board on the ground to wedge the upright board against.


Contrary to popular belief you really do not need two people to install a thru-hull if you can be a little creative.