encapsulated keel leaking to bilge

jbrockpiano · #1 (**permalink**) 01-27-2008

I have an islander 30 MkII built 1974. I believe the encapsulated fin keel is leaking at the keel hull joint forward. The rate of the leak is about a cup or two per day and is pumped out by the the bilge pumps about every three or four days. I replaced the old Volvo engine last September and installed a yanmar 3YM20. I needed to replace the prop so I took a scuba dive and with the extra air inspected the hull. There is nothing obvious. The previous owner had the bottom painted before I bought this boat last March. I need to haul the boat soon to replace the packing gland with a dripless seal. What should I look for to find this leak and need I be concerned about water in he keel rotting the ballast.

Thanks

Jeff_H · #2 (**permalink**) 01-27-2008

To start with, if your boat does have an encapsulated keel, there is no keel to hull joint. The keel enclosure is laid up with the hull, the ballast placed in it and then the top glassed over. If you are leaking through the encapsulation envelope that is very serious because it is nearly impossible to properly drain and dry out the keel cavity and re-establish a bond between the ballast and the hull. If your boat has iron ballast then this is especially tricky. To some extent a delaminated keel cavity is the beginning of the end of the life of the boat since the strength of the keel has been compromised.

But my recollection is that Islanders have bolt on keels, and while leaking keel bolts are not a great thing have to deal with, the good news is that it is relatively easy to unbolt the keel, check the keelbolts and replace them if necessary, and then reseal the joint.

Respectfully,
Jeff

JohnRPollard · #3 (**permalink**) 01-27-2008

Jbrockpiano,

I'm having some trouble envisioning what you're describing. Normally on a boat that has "encapsulated ballast", there is no distinct "keel hull joint". Generally, the keel is a seamless continuation of the hull fibreglass, without any "joint".

I'm not familiar with your model boat, but could it be that you have a keel that is bolted on? If so, these are not normally referred to as encapsulated ballast. Also, keels attached in this manner can sometimes develop leaks around the keel bolts, but usually you'd see some evidence of a problem when you visually inspect it.

If your boat in fact has encapsulated ballast, again I would expect to see some visual evidence of a problem if the keel area was the source of the water. Aside form the hunch, do you have any other reason to believe the water is coming from the keel area (other than that's where it pools in the bilge)? Small leaks like these can come from lots of different sources and are notoriously difficult to pinpoint.

Hopefully others can shed some light on this.

Edit: I see Jeff responded while I was typing -- sorry for the redundance...

jbrockpiano · #4 (**permalink**) 01-27-2008

I am sure the keel is encapsulated because I was able to track down the guy who made the keels for this model run of boat. You are correct however that it is only a hunch where the leak is coming from. I have checked all thru hulls. I suspected my fresh water tank but I would see a trickle of water forward if that were the case. I will know more on haul out I am just looking for ideas of what to look for. My deck is tight so no water from above. Thanks for your ideas.

camaraderie · #5 (**permalink**) 01-27-2008

jbrock...the easy test is DO YOU HAVE KEEL BOLTS?? If not...you have an encapsulated keel...and big problems if that is where the water is coming from.

jbrockpiano · #6 (**permalink**) 01-27-2008

Any other ideas about where the water might be coming from ? I only guess at the spot where the keel meets bilge. Water is clear not rusty. I have not tasted it for salt. Any ideas are appreciated. Thanks

JB

camaraderie · #7 (**permalink**) 01-27-2008

Are you sure your packing gland on the drive shaft is not dripping a little like most do?

ianhlnd · #8 (**permalink**) 01-27-2008

A cup of water a day isn't very much water. First of all, taste it and hope it's not water from a leak in the head

Then check your packing gland. Is it dripping, about a drop every 15 seconds or so? How about hoses, go around and squeeze them and see if any are hard or crunchy, may be a crack. Check every possible source of water from water heater to thru hulls. Close all thru holes and see if water still accumulates. Does your water pump go on every hour or so? Just questions you have to ask yourself. Also, if this is a recent problem, have you done any work with the hoses or pumps? Good luck.

jbrockpiano · #9 (**permalink**) 01-27-2008

Not the packing gland. The engine bilge is separate from forward bilge. Perhaps I am worst case thinking when I think of the hull leaking. I will take another look at the fresh water tank and hoses. The holding tank area is dry.
Any other thoughts or ideas are appreciated. The bilge pump cycles about every three days or so. Not a fast leak but I want to know where the water is coming from.

brak · #10 (**permalink**) 01-27-2008

Are you certain the leak comes from below waterline? Is there any corelation with amount of rainfall and such?

Also, is your boat like the one shown here: http://www.islander30.org/i30-pics.htm
If so, this one has a bolted on keel (integral keels are much wider at the top and have a gradual bend into the rest of the hull, and in general don't look anything like this one).