3. Drill a Hole for the Drain
Use a sharp 1/8-inch drill bit to bore a pilot hole, then a sharp 1/2-inch bit to drill the final hole for the drain fitting. Dial the drill motor up to highest speed and apply only light pressure at 90 degrees to the surface to cut the cleanest hole possible. While the drain is 3/8-inch in diameter, once you press on the clear vinyl hose, the assembly will fit snugly and securely in the 1/2-inch hole. Drill too slowly or apply too much pressure and you’ll bugger up the fiberglass.
4. Snake the Hose In and Up
Push a length of 3/8-inch-inside-diameter clear vinyl hose through the hole and snake it up inside the gunwale to the hole for the rod holder. This is fairly easy, though it might necessitate gouging away a bit of foam around the area where the bottom of the rod holder will sit. It will also require more hose than you will eventually need to install the drain.
5. Attach Hose to the Rod-Holder Drain
Press the upper end of the hose onto the hose barb of the drain cup. For an extra measure, you can use tie-wraps to secure the hose to the barb. With this done, reinstall the rod holder, pulling out excess hose as you lower the rod tube in place. Be sure to bed the rod-holder flange and mounting screws with marine sealant to keep water from seeping underneath and below.
6. Install the Push-In Drain
Trim the excess hose, leaving about 1 1/8 inches hanging out of the hole. Press the drain fitting onto the hose, and then push the assembly into the 1/2-inch hole. Apply a bit of marine sealant to the inside of the drain flange before seating it. This press-fit will be tight and might require a few taps from a rubber mallet to seat it completely. To make sure there are no kinks in the tubing, pour some water in the rod holder to see that it drains freely.