HELP - CD31 waste holding tank taking on water.

[bleslie50]

I recently had a new Beta marine engine installed in my "83 Cape Dory 31. After the installation was complete, the boat was launched and problems developed. I went to the boat a few days later and found that water was up to the cabin sole and flooding the cabin. After running the bilge pump and operating the whale pump in the cockpit, the flooding was over.....or, temporarily. I then discovered water coming up through the engine mount area, water coming through the previous motor mount holes. Alerting the install team, they quickly responded and plugged the holes and the leaking stopped. I thought I was ready to get the boat ready for sailing, so hoisted sails- main, jib and staysail. I also decided to add water to head for use for the season. A couple days later, there was evidence of an odor from the head, then noticed that water was seeping out around the inspection cover that lies above the holding tank. It became obvious that the tank was full. I had used the head a few times, but not near enough for a 28 gallon tank to be full this early in the season. We decided to have the tank pumped and did so promptly. After leaving the dock, we proceeded to the mooring and thought it would be a good idea to check the tank. Upon doing so, and after a period of maybe 25 minutes, the tank had gained about 12" of water. I would guess the tank was full within an hour or so. This seems to be fresh lake water being in the Great Lakes and we have no idea where it is coming from.
I apologize for such a lengthy post, but wanted to be sure to try and convey the details that lead the boat to this
state.
I have read over the years that the 31 has had issues with holding tank problems leaking into the bilge, but I have no idea where this water can be coming from. On this coming Tues, I am scheduled to haul the boat out and look for possible leaks. Any help would be greatly appreciated.
Thanks in advance, Guy

[Skipd]

Sorry to hear about the issue and good choice on the Beta engine. I own a CD30B and have owned a 25D. In both boats the holding tank is in the trailing edge of the keel. Not sure where the holding tank is on the 31. I do know of a case on a 25D when re-powered that they also worked on the cutless bearing where the shaft log is fiberglass. In the process of changing the bearing they cracked the glass and it was not discovered until the boat was launched. The 1984 25D has a fiberglass shaft log and the 1985 30B has a bronze log. Possibly your 1983 31 has a fiberglass log and the cutless bearing was worked on? If so, I could see where a crack in that area might work its way into the holding tank.

Hope this helps

Thanks

[bleslie50]

Thanks for your reply. My biggest frustration is not having any reference as to how the waste tank is incorporated into the hull … can’t find any reference anywhere. At this point I’m running blind as to why water can seep into that tank and not appear in the bilge.

[gonesail]

lifting and launching a boat can put considerable pressure on the bilge areas especially if they don't get the straps right. not sure what you mean by plugging the holes.

[Skipd]

If similar to the CD25D and CD30B (which does not have a reverse transmission) the holding tank is fiberglass, elongated shape, more narrow at the base, at the aft end of the bilge, it is the aft “wall” in the bilge and extends back towards the rudder. On the CD30B the air vent and outlet port to the holding tank sit directly under the engine in the fiberglass/gelcoat oil pan.
The engine bed stringers and oil pan are molded into a one piece unit which is then glassed onto the hull. It appears this way, makes sense from a build standpoint. Water coming through the previous mount’s holes is perplexing. Might indicate the engine bed was shifted or compromised in some way and water is coming in from under it. In that case checking the shaft log and the raw water intake and cockpit seacocks for leaking, the leaking making its way down under the bed? Just some thoughts.

Thanks

[John Ring]

Is there any chance that holding tank wasn't fully emptied before winter storage and froze/expanded over the winter?
John Ring
CD36 Tiara