Capping a thru-hull

[Roc]

The bottom line is the ONE vent, through the stanchion, does not do anything with allowing air (i.e. oxygen) into the tank.  Peggie advised me to route my second line forward, at a 45 degree angle (not straight up from the tank to the rub rail).  That's why I ran it forward toward the bow and exited the hull where the cabinet is on the v-berth port side, just below the rub rail (if you remove the screws along the frame, that cabinet comes out in one piece, exposing the hull).  The hull flares in at that point, as opposed to amidships, where that area could be in the water when heeling.  She said leave the stanchion vent alone since more venting is better than less.  If anything that would help with cross ventilation.  Here's a picture.  You can see the vent right below the rub rail, where the toe rail splits.

[Ron Hill]

Jim : Measure the diameter and go to a hardware store or Home depot and get a PVC cap that will fit over the fitting. 
Then epoxy the cap on.

A thought

[Noah]

I would double-check/research the "correct" epoxy and technique if you go this route. West G-flex may work OK, but I would flame treat the plastic parts first before gluing.

[KWKloeber]

- ....and suggest roughening the surfaces so the epoxy has some bite.

I'd feel much safer epoxying something inside that was an interference fit rather than outside the fitting.



2-1/2" is a hefty thru hull -- are you sure of that dim?  Is that ID or OD of the plastic?

Another thought since it is above the water line - rather than a grind, large bevel-out, fill/mat, fair, paint or gel coat job (I wouldn't want that) is a expanding pipe plug.