Integrity of the 26SWater Ballast Tank

[Chris Hansel]

We have a 1990 26S Water Ballast Boat. We put the boat in the water for the first time in 7 years and filled the ballast tank. Five days later, we discovered that about a quart of water in the starboard holes. Also, the water level in the ballast tank has dropped about 2". The water seems to be coming from near the top center of the ballast tank right in front of the glass door. Here is my question. Is there a pressure safety relief valve kicks in if the ballast tank is overloaded. If so, is there a line to remove the excess water to one of the bilge holes? Assuming that none of the above is true, and in fact there is a hairline crack in the front of the water ballast, how serious of a repair is this? Thank you!

 

[tnn@halcyon.com]

A Clue-I dont own one yet but this may help

Boats built since spring 1999 have a new deck structure. Older boats have a balsa-cored deck and companionway hatch. The new deck is stiffened by a series of solid fiberglass U-shaped beams with an outer flange bonded to the inside of the deck. The beams, which are on 4"-6" centers, are filled with foam, over which are laid layers of 1.5-oz. mat; the deck liner is then laid over the deck, which compresses the foam and bonds the deck and liner.  MacGregor said the new method produces a stronger structure and avoids the problems of rot with balsa. The process also reduces weight by 125 lbs.  Water ballast is carried in a chamber that runs from 3' forward of the transom to the V-berth; it is 4' wide and acts as a longitudinal stringer. It is enclosed by a fiberglass module bonded to the hull.  This leaves precious little area below the sole for a bilge. Because there is no way to inspect the bilge without looking behind the galley, there is no way of knowing how much water is in it. The company now drills a 1/2" hole in the sole below the companionway to allow bilge water to appear on the floor of the main cabin.  “Without the hole it is possible for the boat to collect a really large, stability-threatening load of bilge water,” MacGregor said. “Since the liner floor area is essentially a watertight tub, the skipper had no way of knowing until it reached the level of the cutout in the face of the galley.”  “I prefer a more obvious warning. When he steps in the cabin and ends up with water up to his ankles he will get the message. I recommend owners of older boats make a similar hole,” being careful not to drill into the water tank.  One owner said cleaning up bilge water on the sole is messy.

 

[Mike]

More info

I posted this question at http://www.trailersailor.com/forums/macgregor/I've noticed water in the interior starboard storage compartment where my interior battery is located. This is the compartment under the starboard seat in the galley of the boat. I don't believe it is rain water, since we sponged it all out and then about 2 hours later had another liter of water in there. Could this possibly be water coming back in the sink drain that is above the waterline on the starboard side of the boat? Possibly a loose connection from the sink drain to the fitting? A leak in the water ballast to this compartment? Any ideas would be helpful. Thanks, Mike Got this response so far:My 26S took about three tries to sponge out all the water in the "bilge" on the starboard side. I would dry it out and get it very dry, then come back a couple of days later and get another pint or so out. This was while it was on the trailer with no rain!!! I fathomed the source was from two places. The texture of the interior of the fiberglass on the hull would hold the minimal water back and only let it come down REAL SLOWLY and I had a small pool of water on top of the ballast tank under the head. This water pooled in a small depression and would only spill into the bilge when the boat was moved about 5 degrees side to side. Again, the texture of the fiberglass slowed the rate of flow so much you couldn't really tell it was wet for several hours. A liter or so of water can hide in lots of places in these boats!