SHOP: leakproof through bulkhead hose

In a previous post I have described a solution for a hydration system.
The water bladder sits under the deck, on a “shelf”, and the drinking hose sits in front of me on the deck.
In the Nordkapp LV the deck is lower and less space is available in the foredeck.
Water bottles positioned under the bungees on deck just don’t cut it as they often end up in the sea, especially in rougher conditions.
While on short trips carrying water on the PFD is a possible solution (small amount of water) in the heat of summer in Queensland a liter of water does not get you far.
Hydration in a subtropical locale is a serious consideration.
The water bladder could not go behind the seat (Valley makes sure that the rear cockpit bulkhead is tight against the seat) so the best solution was to place it in the day hatch.
I wanted a positive seal between the drinking hose of the hydration system and the bulkhead.
A simple hole that is just undersized drilled in the deck might not do the job: small amounts of water could still get through and wet items that are otherwise totally dry in a Valley hatch.
I decided to position the drinking hose to the left of the cockpit.
On the right hand side there is the day hatch cover and the outlet spigot for the electric bilge pump.



After drilling a smaller hole with a high speed drill (Dremel_ I use high speed or gel coat chipping can occur) I enlarged it to a slightly undersized dimension for the clear PVC water hose.
I placed an “O” ring on the hose that is slightly constrictive and let it sit on the hose for a while.
The “O” ring would create a small indent in the hose making sure it will really seal well.


I roughened up a circle on the gel coat around the hole, clear off the “O” ring, cleaned the surface with acetone and inserted a slightly greased up (mold release) hose and “O” ring hard against the gel coat.

roughened-up circle on gel coat; hose and "O" ring inserted
I mixed up a small quantity of West System epoxy 105 with 207 hardener (UV stabilized), added some tint (I didn’t like the pale yellow color) and thickened it with microfiber (for strength and workability).
With a toothpick I carefully covered the “O” ring creating a full encasement of the ring.

After curing it overnight I removed the hose (it released easily since it was greased up) and shaved away the excess epoxy to make a smooth “fitting”

epoxy still needs polishing
The “O” ring is now encased in the resin with the rubber surface against the PVC hose making it really leak proof.

PS MAR'10 For a much simpler solution that does not require epoxy Kiwibird managed to source just the right size rubber grommet.

It apppears that her solution is just as effective as mine.

If you can get hold of a grommet that fits the hose tightly I suggest to follow her set up.

The hose can still be slid in-out to shorten or lengthen it according to the paddler's needs.

The hose end inside the day hatch has a quick release coupling that came with the bladder so removing and filling up the bladder is a breeze.
The hose is usually stashed under the deck bungees and can be easily reached when needed for a drink.

After trying different solutions for a drinking system this one seems to address all the shortcomings of the other(*) systems.

* other systems that I tried:

-1) water bottle on deck: not enough water, fall off and hinder some paddle strokes.
-2) water bladder on PFD: if enough water in bladder for a day’s supply PFD becomes rather heavy on the shoulders. Also hinders rolling.
-3) water bladder in cockpit and drinking hose threaded through tunnel of spray deck: bad idea in case of wet exit (rough waters) and inevitably pain in the butt when forgetting to remove before landing :-)

PS: Kiwibird simplified the drink hose system by using a rubber fitting that needs no epoxy work; details here